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Lundin J, Suutala A, Holmström O, Henriksson S, Valkamo S, Kaingu H, Kinyua F, Muinde M, Lundin M, Diwan V, Mårtensson A, Linder N. Diagnosis of soil-transmitted helminth infections with digital mobile microscopy and artificial intelligence in a resource-limited setting. PLoS Negl Trop Dis 2024; 18:e0012041. [PMID: 38602896 PMCID: PMC11008773 DOI: 10.1371/journal.pntd.0012041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 02/28/2024] [Indexed: 04/13/2024] Open
Abstract
BACKGROUND Infections caused by soil-transmitted helminths (STHs) are the most prevalent neglected tropical diseases and result in a major disease burden in low- and middle-income countries, especially in school-aged children. Improved diagnostic methods, especially for light intensity infections, are needed for efficient, control and elimination of STHs as a public health problem, as well as STH management. Image-based artificial intelligence (AI) has shown promise for STH detection in digitized stool samples. However, the diagnostic accuracy of AI-based analysis of entire microscope slides, so called whole-slide images (WSI), has previously not been evaluated on a sample-level in primary healthcare settings in STH endemic countries. METHODOLOGY/PRINCIPAL FINDINGS Stool samples (n = 1,335) were collected during 2020 from children attending primary schools in Kwale County, Kenya, prepared according to the Kato-Katz method at a local primary healthcare laboratory and digitized with a portable whole-slide microscopy scanner and uploaded via mobile networks to a cloud environment. The digital samples of adequate quality (n = 1,180) were split into a training (n = 388) and test set (n = 792) and a deep-learning system (DLS) developed for detection of STHs. The DLS findings were compared with expert manual microscopy and additional visual assessment of the digital samples in slides with discordant results between the methods. Manual microscopy detected 15 (1.9%) Ascaris lumbricoides, 172 (21.7%) Tricuris trichiura and 140 (17.7%) hookworm (Ancylostoma duodenale or Necator americanus) infections in the test set. Importantly, more than 90% of all STH positive cases represented light intensity infections. With manual microscopy as the reference standard, the sensitivity of the DLS as the index test for detection of A. lumbricoides, T. trichiura and hookworm was 80%, 92% and 76%, respectively. The corresponding specificity was 98%, 90% and 95%. Notably, in 79 samples (10%) classified as negative by manual microscopy for a specific species, STH eggs were detected by the DLS and confirmed correct by visual inspection of the digital samples. CONCLUSIONS/SIGNIFICANCE Analysis of digitally scanned stool samples with the DLS provided high diagnostic accuracy for detection of STHs. Importantly, a substantial number of light intensity infections were missed by manual microscopy but detected by the DLS. Thus, analysis of WSIs with image-based AI may provide a future tool for improved detection of STHs in a primary healthcare setting, which in turn could facilitate monitoring and evaluation of control programs.
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Affiliation(s)
- Johan Lundin
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Antti Suutala
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Oscar Holmström
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Samuel Henriksson
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | - Severi Valkamo
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | | | - Felix Kinyua
- Kinondo Kwetu Hospital, Kinondo, Kwale County, Kenya
| | - Martin Muinde
- Kinondo Kwetu Hospital, Kinondo, Kwale County, Kenya
| | - Mikael Lundin
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Vinod Diwan
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Global Health & Migration Unit, Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden
| | - Nina Linder
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
- Global Health & Migration Unit, Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden
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Espiau M, Ajanovic S, Zarzuela F, Maturana CR, Soler-Palacín P, Soriano-Arandes A, Sulleiro E. Management of paediatric soil-transmitted helminthiasis in a non-endemic area: experience in a reference international health unit. Parasitol Res 2024; 123:152. [PMID: 38441714 DOI: 10.1007/s00436-024-08171-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 02/26/2024] [Indexed: 03/07/2024]
Abstract
Soil-transmitted helminth (STH) infections inflict disability worldwide, especially in the poorest communities. Current therapeutic options against STHs show limited efficacy, particularly against Trichuris trichiura. The empirical management of patients coming from high-prevalence areas has been suggested for non-endemic areas. This study aimed to describe the management of STH infections in a non-endemic setting using an individualised approach. We performed a retrospective, descriptive study of all patients up to 16 years of age with STH infections attended at an international health unit in a non-endemic area (2014-2018), including all T. trichiura, Necator americanus, Ancylostoma duodenale, and Ascaris lumbricoides infections diagnosed using a formol-ether concentration technique and direct visualisation. Patients were treated according to current international guidelines. Sixty-one stool samples from 48 patients testing positive for STHs were collected, with 96% (46/48) reporting a previous long-term stay in endemic areas. Cure rates with 3-day benzimidazole regimens were 72% for T. trichiura, 40% for hookworms, and 83% for A. lumbricoides. The results were not influenced by any reinfection risk due to the study being performed in a non-endemic area. Patients coming from STH-endemic areas should be evaluated with appropriate diagnostic tools and followed up until cure control results. Cure rates in our cohort were moderate to low, similar to those published in studies in endemic areas. The efficacy of current treatment options is insufficient to recommend a specific empirical approach in high-income countries' healthcare systems.
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Affiliation(s)
- Maria Espiau
- Paediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sara Ajanovic
- Paediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Francesc Zarzuela
- Microbiology Department, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Carles Rubio Maturana
- Microbiology Department, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Pere Soler-Palacín
- Paediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Antoni Soriano-Arandes
- Paediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Elena Sulleiro
- Microbiology Department, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain.
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Ulaganeethi R, Shettikothanuru Ramachandrappa VK, Rajkumari N, Dorairajan G, Saya GK. Performance of microscopy compared to conventional PCR in identification of soil-transmitted helminth infections among antenatal women in a low-prevalence setting. Indian J Med Microbiol 2023; 46:100427. [PMID: 37945120 DOI: 10.1016/j.ijmmb.2023.100427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/30/2023] [Accepted: 07/03/2023] [Indexed: 11/12/2023]
Abstract
PURPOSE Traditional microscopy-based methods may provide inaccurate estimates of Soil transmitted helminth (STH) infections in mild intensity of infection. Therefore, we aimed to determine the prevalence of STH infections using molecular diagnostic methods and compare the diagnostic performance of microscopy with polymerase chain reaction (PCR) in stool samples collected from pregnant women in primary care settings in Puducherry, India. METHODOLOGY A singleplex PCR assay was developed to detect three species of STHs, namely Ascaris lumbricoides, Necator americanus, and Ancylostoma duodenale, by targeting the internal transcribed spacer regions (ITS1 and ITS2) of 5.8S rRNA. The PCR generated 420, 662, and 515 base pairs of DNA for the respective organisms. In addition to singleplex PCR, wet and concentration microscopy techniques were used. The results were expressed as percentages with 95% confidence intervals, and the diagnostic performance of microscopy was compared with PCR in terms of sensitivity, specificity, and positive, negative predictive values and kappa statistics. RESULTS Among the 650 pregnant women included, 48.8% were aged 25 years or less, 59% were primigravida, and half were from rural areas. The overall prevalence of any STH infection was higher in PCR compared to microscopy (8.9% vs. 7.2%). The prevalence of Ascaris lumbricoides was higher by microscopy (5.4% vs 2.6%), while the prevalence of Necator americanus was higher by PCR (6.3%) than by microscopy (1.8%). No species of Ancylostoma duodenale was detected. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of microscopy for detecting any STH infection was 22.4%, 94.3%, 27.7%, and 92.5%, respectively. The agreement between microscopy and PCR for the identification is as follows: for any STH infection, k = 0.12, Ascaris k = 0.16, and Necator k = 0.20, respectively. CONCLUSION The prevalence of any STH infection identified by PCR was higher than microscopy, and the agreement between the two methods was poor.
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Affiliation(s)
- Revathi Ulaganeethi
- Department of Preventive and Social Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
| | | | - Nonika Rajkumari
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), India.
| | - Gowri Dorairajan
- Department of Obstetrics and Gynaecology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
| | - Ganesh Kumar Saya
- Department of Preventive and Social Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
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Lauffer A, Piazzon ML, Giovannone F, Flesher S, Kilgore JT. Bilious Worm Emesis Secondary to Intestinal Helminthic Infection. J Pediatr 2023; 262:113587. [PMID: 37393043 DOI: 10.1016/j.jpeds.2023.113587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 07/03/2023]
Affiliation(s)
- Andrea Lauffer
- Division of Pediatric Hospital Medicine Department of Pediatrics Marshall University Joan C. Edwards School of Medicine Huntington, West Virginia
| | - Mariana Lanata Piazzon
- Division of Pediatric Infectious DiseasesDepartment of PediatricsMarshall University Joan C. Edwards School of MedicineHuntington, West Virginia
| | | | - Susan Flesher
- Division of Pediatric Hospital MedicineDepartment of PediatricsMarshall University Joan C. Edwards School of MedicineHuntington, West Virginia
| | - Jacob T Kilgore
- Division of Pediatric Infectious Diseases Department of Pediatrics Marshall University Joan C. Edwards School of Medicine Huntington, West Virginia
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Nguemnang Kamdem C, Soubgwi Fogue P, Zebaze Tiofack AA, Mezajou Mewamba E, Tekeu Mengoue LE, Womeni MH, Simo G. Assessment of the capacity of Whatman filter papers as support to store stools for the molecular diagnostic testing of soil-transmitted helminthiasis. J Microbiol Methods 2023; 213:106824. [PMID: 37717625 DOI: 10.1016/j.mimet.2023.106824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023]
Abstract
Storage of stools for the detection of soil-transmitted helminths (STH) remains challenging for the molecular diagnostic testing of STH infections. This study aimed to overcome this challenge by assessing the capacity of Whatman filter papers to store stools for the molecular detection of STHs. Stool samples were collected from school-aged children of soil-transmitted helminthiasis endemic areas of Cameroon and then, analysed using Kato Katz technique. For this study, 128 and 40 stool samples respectively with and without STH eggs were analysed. From each sample, 10, 20, 40 and 80 mg of stool were weighted and spread on 6 grades of Whatman filter papers that were stored at room temperature from one to ten weeks. DNA was extracted from spread stool using CTAB based-method. The amount of stool to spread on filter papers and the grade of filter paper offering good storage were determined by amplifying specific DNA fragments of Ascaris lumbricoides. The capacity of filter papers to store stool samples for several weeks before the molecular detection of STH species was assessed by amplifying specific DNA fragments of different STHs. The amplification rates of A. lumbricoides were significantly higher (P < 0.0001) for 10 and 20 mg of stored stools. Stools spread on Whatman paper grade 2 yielded the highest amplification rate of 100% for A. lumbricoides, T. trichiura and hookworm. PCR revealed STH infections in all the 128 spread stools carrying STH eggs. It also revealed Necator americanus and Ancylostoma duodenale respectively in 10 and 13 of 15 spread stools contained hookworm eggs. PCR confirmed the co-infections of these hookworm species as well as that of A. lumbricoides and Trichuris trichiura in 7 spread stools. Out of 40 stools without STH eggs, PCR revealed that 5 (12.5%) and 9 (22.5%) had respectively A. lumbricoides and T. trichiura infections. The amplification rate of each STH species was 100% from one to 8 weeks and decreased to 86.7% after 10 weeks of storage. This study highlighted the capacity of filter papers to store stools for the molecular detection of STHs. Storing stools on these papers will enable to monitor and evaluate control programs and ensure post-elimination surveillance.
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Affiliation(s)
- Cyrille Nguemnang Kamdem
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Pythagore Soubgwi Fogue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Auvaker Arnol Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Loic Edmond Tekeu Mengoue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Macaire Hilaire Womeni
- Unité de Recherche de Biochimie, des plantes Médicinales, des Sciences alimentaires et Nutrition, University of Dschang, Dschang, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon.
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Vanhooren M, Stoefs A, Van Den Broucke S, Van Esbroeck M, Demuyser T, Kindt S. Intestinal helminthic infections: a narrative review to guide the hepatogastroenterologist. Acta Gastroenterol Belg 2023; 86:460-473. [PMID: 37814562 DOI: 10.51821/86.3.11895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
Intestinal helminthic infections are not uncommon in Western Europe, mainly due to modern travel, emigration and globalization. Moreover, some helminthic infections are endemic in Western Europe and are part of the everyday clinical practice. The hepatogastroenterologist should therefore recognize and manage these patients or at least refer them to appropriate reference centers. Signs and symptoms are often unspecific or even absent. Discerning the disease at an early stage avoids expensive diagnostic testing, life-threatening complications and in some cases even further spread of the disease. This review article aims to guide the hepatogastroenterologist when suspecting a helminthic infection by addressing the most prevalent symptoms, summarizing the most probable associated helminthic entities, highlighting practical steps in diagnosis and available treatments.
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Affiliation(s)
- M Vanhooren
- Department of Gastroenterology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - A Stoefs
- Department of Microbiology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - S Van Den Broucke
- Department of Clinical Sciences, Institute of Tropical Medicine Antwerp (ITMA), Antwerp, Belgium
| | - M Van Esbroeck
- Department of Clinical Sciences, Institute of Tropical Medicine Antwerp (ITMA), Antwerp, Belgium
| | - T Demuyser
- Department of Microbiology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
- AIMS lab, Center for Neurosciences, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - S Kindt
- Department of Gastroenterology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
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Ameen E, Nin Zhu S, Morales Guzman C, Taub E, Siles C, Meza Sanchez G, Vilcarromero S, Ramal C, Tangoa N, Marcos LA. Feasibility of Training Community Health Workers to Use Smartphone-Attached Microscopy for Point-of-Care Visualization of Soil-Transmitted Helminths in the Peruvian Amazon. Am J Trop Med Hyg 2023; 108:1175-1182. [PMID: 37068753 PMCID: PMC10540104 DOI: 10.4269/ajtmh.22-0210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 11/21/2022] [Indexed: 04/19/2023] Open
Abstract
The prevalence of soil-transmitted helminths (STH) is high in communities within the Peruvian Amazon despite repeated mass-drug administration, demanding alternative strategies of control. Smartphone-attached microscopy (SAM) permits visualization of STH from a small portable microscope through a smartphone screen, potentially providing an inexpensive and rapid method of STH visualization in communities where diagnostic laboratories with microscopes are inaccessible. In this study, a total of 45 community health workers who work within the health systems of Loreto, Peru, attended a 1-day training session with lectures and practicums on STH and SAM. Participants received a pre- and post-intervention questionnaire. Post-intervention, participants were significantly more confident using SAM and identifying parasite images, symptoms, transmission, and treatment (P ≤ 0.0045). Post-intervention, participants correctly labeled a median of five of seven SAM apparatus components and five of eight steps of Kato-Katz technique, were less likely to choose taking medicine to prevent parasite infection (P = 0.0075), and were more likely to select Kato-Katz technique as a type of diagnostic test (P < 0.0001). Most participants felt ready to use SAM in their communities and stated that it could help rural communities far from health centers or laboratories (24%); provide faster identification, results, diagnosis (19%); permit at-home or on-the-spot visualization (14%); and save money (14%). Results show that community health workers show a high level of willingness and competency to learn about both STH and SAM and may be a yet-unexplored practical method of augmenting STH visualization, bringing healthcare to communities in Loreto with poor access to diagnostic laboratories and clinics.
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Affiliation(s)
- Eve Ameen
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York
| | - Simon Nin Zhu
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York
| | | | - Erin Taub
- Global Health Institute, Stony Brook University Hospital, Stony Brook, New York
| | | | | | | | - Cesar Ramal
- Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
| | - Nolberto Tangoa
- Centro de Salud San Juan, Ministerio de Salud Peruana, Iquitos, Peru
| | - Luis A. Marcos
- Global Health Institute, Stony Brook University Hospital, Stony Brook, New York
- Infectious Diseases Division, Department of Medicine, Stony Brook University, Stony Brook, New York
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Coffeng LE, Vlaminck J, Cools P, Denwood M, Albonico M, Ame SM, Ayana M, Dana D, Cringoli G, de Vlas SJ, Fenwick A, French M, Kazienga A, Keiser J, Knopp S, Leta G, Matoso LF, Maurelli MP, Montresor A, Mirams G, Mekonnen Z, Corrêa-Oliveira R, Pinto SA, Rinaldi L, Sayasone S, Steinmann P, Thomas E, Vercruysse J, Levecke B. A general framework to support cost-efficient fecal egg count methods and study design choices for large-scale STH deworming programs-monitoring of therapeutic drug efficacy as a case study. PLoS Negl Trop Dis 2023; 17:e0011071. [PMID: 37196017 PMCID: PMC10228800 DOI: 10.1371/journal.pntd.0011071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 05/30/2023] [Accepted: 04/13/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) control programs currently lack evidence-based recommendations for cost-efficient survey designs for monitoring and evaluation. Here, we present a framework to provide evidence-based recommendations, using a case study of therapeutic drug efficacy monitoring based on the examination of helminth eggs in stool. METHODS We performed an in-depth analysis of the operational costs to process one stool sample for three diagnostic methods (Kato-Katz, Mini-FLOTAC and FECPAKG2). Next, we performed simulations to determine the probability of detecting a truly reduced therapeutic efficacy for different scenarios of STH species (Ascaris lumbricoides, Trichuris trichiura and hookworms), pre-treatment infection levels, survey design (screen and select (SS); screen, select and retest (SSR) and no selection (NS)) and number of subjects enrolled (100-5,000). Finally, we integrated the outcome of the cost assessment into the simulation study to estimate the total survey costs and determined the most cost-efficient survey design. PRINCIPAL FINDINGS Kato-Katz allowed for both the highest sample throughput and the lowest cost per test, while FECPAKG2 required both the most laboratory time and was the most expensive. Counting of eggs accounted for 23% (FECPAKG2) or ≥80% (Kato-Katz and Mini-FLOTAC) of the total time-to-result. NS survey designs in combination with Kato-Katz were the most cost-efficient to assess therapeutic drug efficacy in all scenarios of STH species and endemicity. CONCLUSIONS/SIGNIFICANCE We confirm that Kato-Katz is the fecal egg counting method of choice for monitoring therapeutic drug efficacy, but that the survey design currently recommended by WHO (SS) should be updated. Our generic framework, which captures laboratory time and material costs, can be used to further support cost-efficient choices for other important surveys informing STH control programs. In addition, it can be used to explore the value of alternative diagnostic techniques, like automated egg counting, which may further reduce operational costs. TRIAL REGISTRATION ClinicalTrials.gov NCT03465488.
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Affiliation(s)
- Luc E. Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Johnny Vlaminck
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Piet Cools
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Matthew Denwood
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | | | - Shaali M. Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | - Mio Ayana
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Daniel Dana
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Michael French
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
- RTI International, Washington District of Columbia, United States of America
| | - Adama Kazienga
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Gemechu Leta
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Leonardo F. Matoso
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
- Nursing school, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Maria P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | | | - Zeleke Mekonnen
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Rodrigo Corrêa-Oliveira
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Simone A. Pinto
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Somphou Sayasone
- Lao Tropical and Public Health Institute, Ministry of Health, Vientiane, Lao People’s Democratic Republic
| | - Peter Steinmann
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Jozef Vercruysse
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
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Bradbury R, Inagaki K, Singh G, Agana U, Patterson K, Malloch L, Rodriguez E, Qvarnstrom Y, Hobbs CV. A Pilot Comparison of Fixatives for Hookworm Real-time Polymerase Chain Reaction. Am J Trop Med Hyg 2023; 108:335-339. [PMID: 36509060 PMCID: PMC9896329 DOI: 10.4269/ajtmh.22-0406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/06/2022] [Indexed: 12/15/2022] Open
Abstract
Polymerase chain reaction (PCR) is increasingly used in the diagnosis of soil-transmitted helminth infections. Despite this, few studies have evaluated the impact of different fecal fixatives on the outcome of fecal helminth qPCR analysis, and none have evaluated the effect of commercial parasitology fixatives commonly used in diagnostic laboratories. We fixed dog feces containing Ancylostoma spp. hookworm eggs in zinc polyvinyl alcohol (Zn-PVA) and Total-Fix, and with 70% ethanol (EtOH) as a control. DNA was extracted at timepoints 11, 33, 64, and 94 days and subjected to Ancylostoma spp. quantitative PCR (qPCR). A linear regression model was created to assess the effect of preservative types on the temporal change of qPCR quantification cycle number (Cq) values, accounting for variances among individual animals. Fixation in 70% EtOH least affected Cq values over 94 days. Total-Fix preservation yielded a higher Cq overall, but there was no significant difference compared with 70% EtOH fixation. Fixation in Zn-PVA resulted in significantly (P < 0.001) higher Cq values than 70% EtOH after only 33 days and loss of amplification at 64 days. Consistent with other helminth fixation studies, 70% EtOH performed well in preserving hookworm DNA over 94 days. Total-Fix provided a comparable alternative for qPCR analysis for hookworm. Fixation in Zn-PVA resulted in loss of detectable hookworm DNA at 64 days, as determined by qPCR.
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Affiliation(s)
| | - Kengo Inagaki
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan
- Department of Pediatrics, Division of Infectious Disease, Children’s of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi
| | - Gurbaksh Singh
- Department of Pediatrics, Division of Infectious Disease, Children’s of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi
| | - Urita Agana
- Department of Pediatrics, Division of Infectious Disease, Children’s of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi
| | - Kayla Patterson
- Department of Pediatrics, Division of Infectious Disease, Children’s of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Lacy Malloch
- Department of Pediatrics, Division of Infectious Disease, Children’s of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi
| | - Eduardo Rodriguez
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Yvonne Qvarnstrom
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Charlotte V. Hobbs
- Department of Pediatrics, Division of Infectious Disease, Children’s of Mississippi, University of Mississippi Medical Center, Jackson, Mississippi
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Roose S, Leta GT, Vlaminck J, Getachew B, Mekete K, Peelaers I, Geldhof P, Levecke B. Comparison of coproprevalence and seroprevalence to guide decision-making in national soil-transmitted helminthiasis control programs: Ethiopia as a case study. PLoS Negl Trop Dis 2022; 16:e0010824. [PMID: 36197895 PMCID: PMC9534397 DOI: 10.1371/journal.pntd.0010824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/16/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND WHO recommends periodical assessment of the prevalence of any soil-transmitted helminth (STH) infections to adapt the frequency of mass drug administration targeting STHs. Today, detection of eggs in stool smears (Kato-Katz thick smear) remains the diagnostic standard. However, stool examination (coprology) has important operational drawbacks and impedes integrated surveys of multiple neglected tropical diseases. Therefore, the aim of the present study was to assess the potential of applying serology instead of coprology in STH control program decision-making. METHODOLOGY An antibody-ELISA based on extract of Ascaris lung stage larvae (AsLungL3-ELISA) was applied in ongoing monitoring activities of the Ethiopian national control program against schistosomiasis and soil-transmitted helminthiasis. Blood and stool samples were collected from over 6,700 students (median age: 11) from 63 schools in 33 woredas (districts) across the country. Stool samples of two consecutive days were analyzed applying duplicate Kato-Katz thick smear. PRINCIPAL FINDINGS On woreda level, qualitative (seroprevalence) and quantitative (mean optical density ratio) serology results were highly correlated, and hence seroprevalence was chosen as parameter. For 85% of the woredas, prevalence based on serology was higher than those based on coprology. The results suggested cross-reactivity of the AsLungL3-ELISA with Trichuris. When extrapolating the WHO coproprevalence thresholds, there was a moderate agreement (weighted κ = 0.43) in program decision-making. Using the same threshold values would predominantly lead to a higher frequency of drug administration. SIGNIFICANCE This is the first time that serology for soil-transmitted helminthiasis is applied on such large scale, thereby embedded in a control program context. The results underscore that serology holds promise as a tool to monitor STH control programs. Further research should focus on the optimization of the diagnostic assay and the refinement of serology-specific program decision-making thresholds.
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Affiliation(s)
- Sara Roose
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
- * E-mail: (SR); (BL)
| | - Gemechu Tadesse Leta
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Johnny Vlaminck
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Birhanu Getachew
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Kalkidan Mekete
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Iris Peelaers
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Peter Geldhof
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
- * E-mail: (SR); (BL)
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11
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Maurelli MP, Alves LC, Aggarwal CS, Cociancic P, Levecke B, Cools P, Montresor A, Ianniello D, Gualdieri L, Cringoli G, Rinaldi L. Ascaris lumbricoides eggs or artefacts? A diagnostic conundrum. Parasitology 2021; 148:1554-1559. [PMID: 34250886 PMCID: PMC8564801 DOI: 10.1017/s0031182021001256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 06/29/2021] [Accepted: 07/04/2021] [Indexed: 11/24/2022]
Abstract
Due to the presence of artefacts in stool samples, the copromicroscopic diagnosis of Ascaris lumbricoides is not always straightforward, particularly in the case of fertilized decorticated eggs. A total of 286 stool samples from 115 schoolchildren in India and 171 adult immigrants in Italy were screened for the presence of A. lumbricoides eggs by both Kato-Katz thick smear and Mini-FLOTAC. If the outer layer of A. lumbricoides eggs was absent, two aliquots of each stool sample were preserved: one for coproculture to identify larvae after development and one to compose a pool of stool for molecular analysis. A total of 64 stool samples (22.4%) were positive for A. lumbricoides using the Kato-Katz thick smear; 36 (56.3%) of these showed mammillated A. lumbricoides eggs, 25 (39.1%) showed elements resembling fertilized decorticated eggs, while three samples (4.7%) showed both mammillated and decorticated eggs. By Mini-FLOTAC, 39 stool samples (13.6%) were positive, while decorticated A. lumbricoides-like eggs were identified as artefacts. These results were confirmed by negative coprocultures and quantitative polymerase chain reaction. Mini-FLOTAC can be used for a reliable diagnosis of A. lumbricoides, thanks to the flotation and translation features which allow a clearer view, resulting in the correct identification of A. lumbricoides eggs.
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Affiliation(s)
- M. P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
| | - L. C. Alves
- Department of Veterinary Medicine, Federal Rural University of Pernambuco, Recife, Brazil
| | - C. S. Aggarwal
- Division of Parasitic Diseases, National Centre for Disease Control, 22 Shamnath Marg, Delhi, India
| | - P. Cociancic
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE-CONICET-UNLP-asociado a CICPBA), La Plata, Buenos Aires, Argentina
| | - B. Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, WHO Collaborating Centre BEL-42, Merelbeke, Belgium
| | - P. Cools
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, WHO Collaborating Centre BEL-42, Merelbeke, Belgium
| | - A. Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - D. Ianniello
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
| | - L. Gualdieri
- Medical Center, Centro per la Tutela della Salute degli Immigrati, Naples, Italy
| | - G. Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
| | - L. Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, WHO Collaborating Centre ITA-116, Naples, Italy
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Grau-Pujol B, Martí-Soler H, Escola V, Demontis M, Jamine JC, Gandasegui J, Muchisse O, Cambra-Pellejà M, Cossa A, Martinez-Valladares M, Sacoor C, Van Lieshout L, Cano J, Giorgi E, Muñoz J. Towards soil-transmitted helminths transmission interruption: The impact of diagnostic tools on infection prediction in a low intensity setting in Southern Mozambique. PLoS Negl Trop Dis 2021; 15:e0009803. [PMID: 34695108 PMCID: PMC8568186 DOI: 10.1371/journal.pntd.0009803] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 11/04/2021] [Accepted: 09/09/2021] [Indexed: 11/19/2022] Open
Abstract
World Health Organization goals against soil-transmitted helminthiases (STH) are pointing towards seeking their elimination as a public health problem: reducing to less than 2% the proportion of moderate and heavy infections. Some regions are reaching WHO goals, but transmission could rebound if strategies are discontinued without an epidemiological evaluation. For that, sensitive diagnostic methods to detect low intensity infections and localization of ongoing transmission are crucial. In this work, we estimated and compared the STH infection as obtained by different diagnostic methods in a low intensity setting. We conducted a cross-sectional study enrolling 792 participants from a district in Mozambique. Two stool samples from two consecutive days were collected from each participant. Samples were analysed by Telemann, Kato-Katz and qPCR for STH detection. We evaluated diagnostic sensitivity using a composite reference standard. By geostatistical methods, we estimated neighbourhood prevalence of at least one STH infection for each diagnostic method. We used environmental, demographical and socioeconomical indicators to account for any existing spatial heterogeneity in infection. qPCR was the most sensitive technique compared to composite reference standard: 92% (CI: 83%- 97%) for A. lumbricoides, 95% (CI: 88%- 98%) for T. trichiura and 95% (CI: 91%- 97%) for hookworm. qPCR also estimated the highest neighbourhood prevalences for at least one STH infection in a low intensity setting. While 10% of the neighbourhoods showed a prevalence above 20% when estimating with single Kato-Katz from one stool and Telemann from one stool, 86% of the neighbourhoods had a prevalence above 20% when estimating with qPCR. In low intensity settings, STH estimated prevalence of infection may be underestimated if based on Kato-Katz. qPCR diagnosis outperformed the microscopy methods. Thus, implementation of qPCR based predictive maps at STH control and elimination programmes would disclose hidden transmission and facilitate targeted interventions for transmission interruption.
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Affiliation(s)
- Berta Grau-Pujol
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- Mundo Sano Foundation, Buenos Aires, Argentina
- * E-mail:
| | - Helena Martí-Soler
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
| | - Valdemiro Escola
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Maria Demontis
- Department of Parasitology, Centre of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | | | - Javier Gandasegui
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Grulleros, León, Spain
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana, León, Spain
| | - Osvaldo Muchisse
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Maria Cambra-Pellejà
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Grulleros, León, Spain
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana, León, Spain
| | - Anelsio Cossa
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Maria Martinez-Valladares
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Grulleros, León, Spain
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana, León, Spain
| | - Charfudin Sacoor
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Lisette Van Lieshout
- Department of Parasitology, Centre of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Jorge Cano
- Expanded Special Project for Elimination of NTDs, World Health Organization Regional Office for Africa, Brazzaville, The Republic of the Congo
| | - Emanuele Giorgi
- Centre for Health Informatics, Computing and Statistics, Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, United Kingdom
| | - Jose Muñoz
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
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Cantera JL, White HN, Forrest MS, Stringer OW, Belizario VY, Storey HL, de Hostos EL, de los Santos T. Sensitive and semiquantitative detection of soil-transmitted helminth infection in stool using a recombinase polymerase amplification-based assay. PLoS Negl Trop Dis 2021; 15:e0009782. [PMID: 34516554 PMCID: PMC8459997 DOI: 10.1371/journal.pntd.0009782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 09/23/2021] [Accepted: 09/01/2021] [Indexed: 01/03/2023] Open
Abstract
Background Soil-transmitted helminths (STHs) are parasitic nematodes that inhabit the human intestine. They affect more than 1.5 billion people worldwide, causing physical and cognitive impairment in children. The global strategy to control STH infection includes periodic mass drug administration (MDA) based on the results of diagnostic testing among populations at risk, but the current microscopy method for detecting infection has diminished sensitivity as the intensity of infection decreases. Thus, improved diagnostic tools are needed to support decision-making for STH control programs. Methodology We developed a nucleic acid amplification test based on recombinase polymerase amplification (RPA) technology to detect STH in stool. We designed primers and probes for each of the four STH species, optimized the assay, and then verified its performance using clinical stool samples. Principal findings Each RPA assay was as sensitive as a real-time polymerase chain reaction (PCR) assay in detecting copies of cloned target DNA sequences. The RPA assay amplified the target in DNA extracted from human stool samples that were positive for STH based on the Kato-Katz method, with no cross-reactivity of the non-target genomic DNA. When tested with clinical stool samples from patients with infections of light, moderate, and heavy intensity, the RPA assays demonstrated performance comparable to that of real-time PCR, with better results than Kato-Katz. This new rapid, sensitive and field-deployable method for detecting STH infections can help STH control programs achieve their goals. Conclusions Semi-quantitation of target by RPA assay is possible and is comparable to real-time PCR. With proper instrumentation, RPA assays can provide robust, semi-quantification of STH DNA targets as an alternative field-deployable indicator to counts of helminth eggs for assessing infection intensity. More than 1.5 billion people are infected with parasitic intestinal worms called soil-transmitted helminths. Infection is transmitted by helminth eggs in human feces, which contaminate soil in areas with poor sanitation. Adverse health effects include physical and cognitive impairment in children. A key strategy to control infection is periodic mass drug administration for populations with a high prevalence of disease based on the results of diagnostic testing. The current microscopy method for detecting infection, however, has limited ability to detect disease as the intensity of infection decreases with repeated mass drug administration. To address limitations of current diagnostic methods, we developed a novel technique to diagnose infections, including those at very low levels of intensity, by detecting helminth DNA in stool samples. Our initial studies suggest that the new diagnostic technique reliably detects the presence of intestinal worms, even at low intensities of infection, and may be more useful than currently available diagnostic tools for guiding the use of periodic mass drug administration to eliminate disease in low-resource settings.
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Affiliation(s)
| | | | | | | | - Vicente Y. Belizario
- Department of Parasitology, College of Public Health, University of the Philippines, Ermita, Manila, Philippines
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14
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Zendejas-Heredia PA, Colella V, Hii SF, Traub RJ. Comparison of the egg recovery rates and limit of detection for soil-transmitted helminths using the Kato-Katz thick smear, faecal flotation and quantitative real-time PCR in human stool. PLoS Negl Trop Dis 2021; 15:e0009395. [PMID: 34038411 PMCID: PMC8153506 DOI: 10.1371/journal.pntd.0009395] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/17/2021] [Indexed: 01/02/2023] Open
Abstract
Background Monitoring the success of soil-transmitted helminth (STH) control programs relies on accurate diagnosis and quantitative assessment of infection prevalence and intensity. As preventative chemotherapeutic program coverage for STH expands, the necessity of gaining insights into the relative or comparative sensitivities, in terms of limits of detection (LOD) and egg-recovery-rates (ERR) for microscopy and quantitative polymerase chain reaction qPCR-based diagnostic techniques becomes imperative to inform suitability for their intended use for large scale STH monitoring and treatment efficacy studies. Methodology/Principal findings The diagnostic performance in terms of ERR and LOD of the Kato-Katz (KK) thick smear technique, sodium nitrate (NaNO3) faecal floatation (FF) and qPCR for the accurate detection and enumeration of STH eggs were calculated and expressed in eggs per gram (EPG), by experimentally seeding parasite-free human faeces with Ascaris spp., Trichuris spp. and Necator americanus eggs representing low, medium and high intensity infections. The efficiency of NaNO3 flotation was also calculated over a range of specific gravities (SpGr) for the optimum recovery of STH eggs. FF of SpGr 1.30 recovered 62.7%, 11% and 8.7% more Trichuris spp., Necator americanus and Ascaris spp. eggs respectively, than the recommended SpGr of 1.20. All diagnostic methods demonstrated strong direct correlation to the intensity of seeded EPG. KK and FF (SpGr 1.30) resulted in significant lower ERRs compared to qPCR (p <0.05). qPCR demonstrated significantly (p <0.05) greater sensitivity with an ability to detect as little as 5 EPG for all three STH, compared to 50 EPG by KK and FF (SpGr 1.30). Conclusions/Significance This study compares the diagnostic parameters in terms of LOD and ERRs of STHs for the KK, FF and qPCR. These results indicate that the diagnostic performance of qPCR assays should be considered by control programs in the phase that aims to seek confirmation of transmission break and cessation of preventive chemotherapy in low-transmission settings, in line with the control targets of the WHO neglected tropical diseases 2030 Roadmap. STH infections predominately affect resource-poor communities and negatively impact on child and maternal health. Diagnostics play a critical role in guiding and informing existing STH control programs and the implementation and evaluation of intervention strategies. The KK technique is most commonly used as per WHO guidelines and is the basis for determining quantitative thresholds for low, moderate and heavy infections. More recently, FF and laboratory-based quantitative PCR techniques have provided alternative options of diagnosing STH infections. A number of studies correlating the relative sensitivity, diagnostic agreement, and egg enumeration of these techniques by comparing field-generated diagnostic data have attempted to correlate quantitative outputs to those defined by the WHO, with little resolution. Moreover, as large-scale deworming programs levels scale up, the necessity to apply techniques that can precisely detect light infections is of outmost importance to establish preventive chemotherapy end-points using more accurate means. In this study we compared the LOD and ERR of seeded non-infected human faecal samples with Ascaris, Trichuris and Necator spp. eggs using KK, FF and qPCR. When compared to copro-microscopy methods, qPCR showed the highest sensitivity for the detection of light-intensity infections and was more accurate in enumerating the original number of eggs per gram of seeded faeces. In addition to this, the results indicated that the diagnostic performance of both KK and FF (using solution at a SpGr of 1.30) were equally efficient and should be considered with their diagnostic limitations in mind, when aiming to monitor STH infections in low-transmission settings.
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Affiliation(s)
- Patsy A. Zendejas-Heredia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Vito Colella
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Sze Fui Hii
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
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15
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Knee J, Sumner T, Adriano Z, Anderson C, Bush F, Capone D, Casmo V, Holcomb D, Kolsky P, MacDougall A, Molotkova E, Braga JM, Russo C, Schmidt WP, Stewart J, Zambrana W, Zuin V, Nalá R, Cumming O, Brown J. Effects of an urban sanitation intervention on childhood enteric infection and diarrhea in Maputo, Mozambique: A controlled before-and-after trial. eLife 2021; 10:e62278. [PMID: 33835026 PMCID: PMC8121544 DOI: 10.7554/elife.62278] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 04/03/2021] [Indexed: 12/12/2022] Open
Abstract
We conducted a controlled before-and-after trial to evaluate the impact of an onsite urban sanitation intervention on the prevalence of enteric infection, soil transmitted helminth re-infection, and diarrhea among children in Maputo, Mozambique. A non-governmental organization replaced existing poor-quality latrines with pour-flush toilets with septic tanks serving household clusters. We enrolled children aged 1-48 months at baseline and measured outcomes before and 12 and 24 months after the intervention, with concurrent measurement among children in a comparable control arm. Despite nearly exclusive use, we found no evidence that intervention affected the prevalence of any measured outcome after 12 or 24 months of exposure. Among children born into study sites after intervention, we observed a reduced prevalence of Trichuris and Shigella infection relative to the same age group at baseline (<2 years old). Protection from birth may be important to reduce exposure to and infection with enteric pathogens in this setting.
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Affiliation(s)
- Jackie Knee
- London School of Hygiene & Tropical Medicine, Faculty of Infectious Tropical Diseases, Disease Control DepartmentLondonUnited Kingdom
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Trent Sumner
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | | | - Claire Anderson
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Farran Bush
- Georgia Institute of Technology, School of Chemical and Biomolecular EngineeringAtlantaUnited States
| | - Drew Capone
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
| | | | - David Holcomb
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of Environmental Sciences and EngineeringChapel HillUnited States
| | - Pete Kolsky
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
| | - Amy MacDougall
- London School of Hygiene & Tropical Medicine, Faculty of Epidemiology and Population Health, Department of Medical StatisticsLondonUnited Kingdom
| | - Evgeniya Molotkova
- Georgia Institute of Technology, School of Biological SciencesAtlantaUnited States
| | | | - Celina Russo
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Wolf Peter Schmidt
- London School of Hygiene & Tropical Medicine, Faculty of Infectious Tropical Diseases, Disease Control DepartmentLondonUnited Kingdom
| | - Jill Stewart
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
| | - Winnie Zambrana
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Valentina Zuin
- Yale-NUS College, Division of Social ScienceSingaporeSingapore
| | | | - Oliver Cumming
- London School of Hygiene & Tropical Medicine, Faculty of Infectious Tropical Diseases, Disease Control DepartmentLondonUnited Kingdom
| | - Joe Brown
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
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16
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Keller L, Patel C, Welsche S, Schindler T, Hürlimann E, Keiser J. Performance of the Kato-Katz method and real time polymerase chain reaction for the diagnosis of soil-transmitted helminthiasis in the framework of a randomised controlled trial: treatment efficacy and day-to-day variation. Parasit Vectors 2020; 13:517. [PMID: 33059756 PMCID: PMC7558729 DOI: 10.1186/s13071-020-04401-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/09/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Accurate, scalable and sensitive diagnostic tools are crucial in determining prevalence of soil-transmitted helminths (STH), assessing infection intensities and monitoring treatment efficacy. However, assessments on treatment efficacy comparing traditional microscopic to newly emerging molecular approaches such as quantitative Polymerase Chain Reaction (qPCR) are scarce and hampered partly by lack of an established diagnostic gold standard. METHODS We compared the performance of the copromicroscopic Kato-Katz method to qPCR in the framework of a randomized controlled trial on Pemba Island, Tanzania, evaluating treatment efficacy based on cure rates of albendazole monotherapy versus ivermectin-albendazole against Trichuris trichiura and concomitant STH infections. Day-to-day variability of both diagnostic methods was assessed to elucidate reproducibility of test results by analysing two stool samples before and two stool samples after treatment of 160 T. trichiura Kato-Katz positive participants, partially co-infected with Ascaris lumbricoides and hookworm, per treatment arm (n = 320). As negative controls, two faecal samples of 180 Kato-Katz helminth negative participants were analysed. RESULTS Fair to moderate correlation between microscopic egg count and DNA copy number for the different STH species was observed at baseline and follow-up. Results indicated higher sensitivity of qPCR for all three STH species across all time points; however, we found lower test result reproducibility compared to Kato-Katz. When assessed with two samples from consecutive days by qPCR, cure rates were significantly lower for T. trichiura (23.2 vs 46.8%), A. lumbricoides (75.3 vs 100%) and hookworm (52.4 vs 78.3%) in the ivermectin-albendazole treatment arm, when compared to Kato-Katz. CONCLUSIONS qPCR diagnosis showed lower reproducibility of test results compared to Kato-Katz, hence multiple samples per participant should be analysed to achieve a reliable diagnosis of STH infection. Our study confirms that cure rates are overestimated using Kato-Katz alone. Our findings emphasize that standardized and accurate molecular diagnostic tools are urgently needed for future monitoring within STH control and/or elimination programmes.
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Affiliation(s)
- Ladina Keller
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Chandni Patel
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Sophie Welsche
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Tobias Schindler
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Eveline Hürlimann
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
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17
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Levecke B, Cools P, Albonico M, Ame S, Angebault C, Ayana M, Behnke JM, Bethony JM, Cringoli G, Dana D, Guillard B, Viet Hoa NT, Kang G, Kattula D, Keiser J, Kotze AC, Matoso LF, Maurelli MP, McCarthy JS, Mekonnen Z, Mirams G, Montresor A, Oliveira RC, Periago MV, Pinto SA, Rinaldi L, Sayasone S, Sumo L, Tchuem-Tchuenté LA, Cam Thach DT, Thomas E, Zeynudin A, Verweij JJ, Vlaminck J, Vercruysse J. Identifying thresholds for classifying moderate-to-heavy soil-transmitted helminth intensity infections for FECPAKG2, McMaster, Mini-FLOTAC and qPCR. PLoS Negl Trop Dis 2020; 14:e0008296. [PMID: 32614828 PMCID: PMC7413557 DOI: 10.1371/journal.pntd.0008296] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 08/07/2020] [Accepted: 04/15/2020] [Indexed: 11/18/2022] Open
Abstract
The World Health Organization (WHO) has defined moderate-to-heavy intensity (M&HI) infections with soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and the two hookworms, Ancylostoma duodenale and Necator americanus) based on specific values of eggs per gram of stool, as measured by the Kato-Katz method. There are a variety of novel microscopy and DNA-based methods but it remains unclear whether applying current WHO thresholds on to these methods allows for a reliable classification of M&HI infections. We evaluated both WHO and method-specific thresholds for classifying the M&HI infections for novel microscopic (FECPAKG2, McMaster and Mini-FLOTAC) and DNA-based (qPCR) diagnostic methods. For this, we determined method-specific thresholds that best classified M&HI infections (defined by Kato-Katz and WHO thresholds; reference method) in two multi-country drug efficacy studies. Subsequently, we verified whether applying these method-specific thresholds improved the agreement in classifying M&HI infections compared to the reference method. When we applied the WHO thresholds, the new microscopic methods mainly misclassified M&HI as low intensity, and to a lesser extent low intensity infection as M&HI. For FECPAKG2, applying the method-specific thresholds significantly improved the agreement for Ascaris (moderate → substantial), Trichuris and hookworms (fair → moderate). For Mini-FLOTAC, a significantly improved agreement was observed for hookworms only (fair → moderate). For the other STHs, the agreement was almost perfect and remained unchanged. For McMaster, the method-specific thresholds revealed a fair to a substantial agreement but did not significantly improve the agreement. For qPCR, the method-specific thresholds based on genome equivalents per ml of DNA moderately agreed with the reference method for hookworm and Trichuris infections. For Ascaris, there was a substantial agreement. We defined method-specific thresholds that improved the classification of M&HI infections. Validation studies are required before they can be recommended for general use in assessing M&HI infections in programmatic settings.
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Affiliation(s)
- Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
- * E-mail:
| | - Piet Cools
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Marco Albonico
- Center for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Negrar, Italy
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Shaali Ame
- Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | | | - Mio Ayana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Jerzy M. Behnke
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jeffrey M. Bethony
- Microbiology, Immunology, and Tropical Medicine, George Washington University Medical Center, Washington D.C., United States of America
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Daniel Dana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | | | - Nguyen Thi Viet Hoa
- Department of Parasitology, National Institute of Malariology, Parasitology and Entomology, Ha Noi, Vietnam
| | - Gagandeep Kang
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Deepthi Kattula
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland & University of Basel, Basel, Switzerland
| | - Andrew C. Kotze
- Division of Agriculture and Food, Commonwealth Scientific and Industrial Research Organization, St. Lucia, Australia
| | - Leonardo F. Matoso
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou - FIOCRUZ, Belo Horizonte, Brazil
| | - Maria P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - James S. McCarthy
- QIMR Berghofer Medical Research Institute, University of Queensland, Brisbane, Australia
| | - Zeleke Mekonnen
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | | | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Rodrigo Corrêa Oliveira
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou - FIOCRUZ, Belo Horizonte, Brazil
| | - Maria V. Periago
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou - FIOCRUZ, Belo Horizonte, Brazil
| | - Simone A. Pinto
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou - FIOCRUZ, Belo Horizonte, Brazil
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Somphou Sayasone
- Lao Tropical and Public Health Institute, Ministry of Health, Vientiane Capital, Lao People’s Democratic Republic
| | - Laurentine Sumo
- Centre for Schistosomiasis and Parasitology, University of Yaoundé I, Yaoundé, Cameroon
| | | | - Dang Thi Cam Thach
- Department of Parasitology, National Institute of Malariology, Parasitology and Entomology, Ha Noi, Vietnam
| | | | - Ahmed Zeynudin
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Jaco J. Verweij
- Laboratory for Medical Microbiology and Immunology, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands
| | - Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
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18
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Cools P, van Lieshout L, Koelewijn R, Addiss D, Ajjampur SSR, Ayana M, Bradbury RS, Cantera JL, Dana D, Fischer K, Imtiaz R, Kabagenyi J, Lok J, McCarthy J, Mejia R, Mekonnen Z, Njenga SM, Othman N, Shao H, Traub R, Van Esbroeck M, Vercruysse J, Vlaminck J, Williams SA, Verweij JJ, van Hellemond JJ, Levecke B. First international external quality assessment scheme of nucleic acid amplification tests for the detection of Schistosoma and soil-transmitted helminths, including Strongyloides: A pilot study. PLoS Negl Trop Dis 2020; 14:e0008231. [PMID: 32544158 PMCID: PMC7319349 DOI: 10.1371/journal.pntd.0008231] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 06/26/2020] [Accepted: 03/17/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Nucleic acid amplification tests (NAATs) are increasingly being used as diagnostic tools for soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale and A. ceylanicum), Strongyloides stercoralis and Schistosoma in human stool. Currently, there is a large diversity of NAATs being applied, but an external quality assessment scheme (EQAS) for these diagnostics is lacking. An EQAS involves a blinded process where test results reported by a laboratory are compared to those reported by reference or expert laboratories, allowing for an objective assessment of the diagnostic performance of a laboratory. In the current study, we piloted an international EQAS for these helminths (i) to investigate the feasibility of designing and delivering an EQAS; (ii) to assess the diagnostic performance of laboratories; and (iii) to gain insights into the different NAAT protocols used. METHODS AND PRINCIPAL FINDINGS A panel of twelve stool samples and eight DNA samples was validated by six expert laboratories for the presence of six helminths (Ascaris, Trichuris, N. americanus, Ancylostoma, Strongyloides and Schistosoma). Subsequently this panel was sent to 15 globally dispersed laboratories. We found a high degree of diversity among the different DNA extraction and NAAT protocols. Although most laboratories performed well, we could clearly identify the laboratories that were poorly performing. CONCLUSIONS/SIGNIFICANCE We showed the technical feasibility of an international EQAS for the NAAT of STHs, Strongyloides and Schistosoma. In addition, we documented that there are clear benefits for participating laboratories, as they can confirm and/or improve the diagnostic performance of their NAATs. Further research should aim to identify factors that explain poor performance of NAATs.
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Affiliation(s)
- Piet Cools
- Laboratory of Parasitology, Ghent University, Merelbeke, Belgium
| | - Lisette van Lieshout
- Leiden University Medical Center, Leiden, The Netherlands
- Dutch Foundation for Quality Assessment in Medical Laboratories, Nijmegen, The Netherlands
| | - Rob Koelewijn
- Dutch Foundation for Quality Assessment in Medical Laboratories, Nijmegen, The Netherlands
- Erasmus University Medical Center, Rotterdam, The Netherlands
| | - David Addiss
- The Task Force for Global Health, Decatur, Georgia, United States of America
| | | | | | - Richard S. Bradbury
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | | | - Kerstin Fischer
- Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Rubina Imtiaz
- Children Without Worms, Decatur, Georgia, United States of America
| | - Joyce Kabagenyi
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - James Lok
- University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - James McCarthy
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Rojelio Mejia
- Baylor College of Medicine, Houston, Texas, United States of America
| | | | | | | | - Hongguang Shao
- University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | | | - Jozef Vercruysse
- Laboratory of Parasitology, Ghent University, Merelbeke, Belgium
| | - Johnny Vlaminck
- Laboratory of Parasitology, Ghent University, Merelbeke, Belgium
| | - Steven A. Williams
- Smith College, Northampton, Massachusetts, United States of America
- University of Massachusetts, Amherst, Massachusetts, United States of America
| | | | - Jaap J. van Hellemond
- Dutch Foundation for Quality Assessment in Medical Laboratories, Nijmegen, The Netherlands
- Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Bruno Levecke
- Laboratory of Parasitology, Ghent University, Merelbeke, Belgium
- * E-mail:
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19
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Benjamin-Chung J, Pilotte N, Ercumen A, Grant JR, Maasch JRMA, Gonzalez AM, Ester AC, Arnold BF, Rahman M, Haque R, Hubbard AE, Luby SP, Williams SA, Colford JM. Comparison of multi-parallel qPCR and double-slide Kato-Katz for detection of soil-transmitted helminth infection among children in rural Bangladesh. PLoS Negl Trop Dis 2020; 14:e0008087. [PMID: 32330127 PMCID: PMC7202662 DOI: 10.1371/journal.pntd.0008087] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 05/06/2020] [Accepted: 01/24/2020] [Indexed: 01/08/2023] Open
Abstract
There is growing interest in local elimination of soil-transmitted helminth (STH) infection in endemic settings. In such settings, highly sensitive diagnostics are needed to detect STH infection. We compared double-slide Kato-Katz, the most commonly used copromicroscopic detection method, to multi-parallel quantitative polymerase chain reaction (qPCR) in 2,799 stool samples from children aged 2–12 years in a setting in rural Bangladesh with predominantly low STH infection intensity. We estimated the sensitivity and specificity of each diagnostic using Bayesian latent class analysis. Compared to double-slide Kato-Katz, STH prevalence using qPCR was almost 3-fold higher for hookworm species and nearly 2-fold higher for Trichuris trichiura. Ascaris lumbricoides prevalence was lower using qPCR, and 26% of samples classified as A. lumbricoides positive by Kato-Katz were negative by qPCR. Amplicon sequencing of the 18S rDNA from 10 samples confirmed that A. lumbricoides was absent in samples classified as positive by Kato-Katz and negative by qPCR. The sensitivity of Kato-Katz was 49% for A. lumbricoides, 32% for hookworm, and 52% for T. trichiura; the sensitivity of qPCR was 79% for A. lumbricoides, 93% for hookworm, and 90% for T. trichiura. Specificity was ≥ 97% for both tests for all STH except for Kato-Katz for A. lumbricoides (specificity = 68%). There were moderate negative, monotonic correlations between qPCR cycle quantification values and eggs per gram quantified by Kato-Katz. While it is widely assumed that double-slide Kato-Katz has few false positives, our results indicate otherwise and highlight inherent limitations of the Kato-Katz technique. qPCR had higher sensitivity than Kato-Katz in this low intensity infection setting. Soil-transmitted helminth infections (STH) (e.g., Ascaris, hookworm, Trichuris) contribute to a large burden of disease among children in low- and middle-income countries. There is increasing interest in implementing large-scale deworming programs to eliminate STH in certain settings. Efforts to monitor whether local elimination has occurred require sensitive diagnostic tests that will not miss positive cases. Kato-Katz, a microscopy-based diagnostic test, has commonly been used to identify STH eggs in stool, but in settings where infection intensity is low, this method frequently misses positive samples because it requires visual identification of small numbers of eggs, and hookworm eggs may degrade prior to visualization. Quantitative polymerase chain reaction (qPCR) is a molecular diagnostic method for detecting STH. It may detect more low intensity infections than Kato-Katz because it identifies STH DNA in stool; DNA can be detected in very small quantities and is less likely to degrade than STH ova. Thus, qPCR is likely to be more accurate than Kato-Katz. This study compared the performance of double-slide Kato-Katz and qPCR using 2,799 stool samples from children aged 2–12 years in a setting in rural Bangladesh with predominantly low STH infection intensity. qPCR was more sensitive than Kato-Katz for hookworm and Trichuris infections. 26% of samples were classified as Ascaris positive by Kato-Katz and negative by qPCR. DNA sequencing of 10 samples confirmed that Ascaris was absent in samples classified as positive by Kato-Katz and negative by qPCR. We conclude that Kato-Katz likely produced false positive results for Ascaris and that qPCR had a higher sensitivity than double-slide Kato-Katz in this low infection intensity setting.
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Affiliation(s)
- Jade Benjamin-Chung
- Division of Epidemiology & Biostatistics, University of California, Berkeley, Berkeley, California, United States of America
- * E-mail:
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Ayse Ercumen
- Division of Epidemiology & Biostatistics, University of California, Berkeley, Berkeley, California, United States of America
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Jessica R. Grant
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | | | - Andrew M. Gonzalez
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Ashanta C. Ester
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Benjamin F. Arnold
- Division of Epidemiology & Biostatistics, University of California, Berkeley, Berkeley, California, United States of America
| | - Mahbubur Rahman
- Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Rashidul Haque
- Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Alan E. Hubbard
- Division of Epidemiology & Biostatistics, University of California, Berkeley, Berkeley, California, United States of America
| | - Stephen P. Luby
- Infectious Diseases & Geographic Medicine, Stanford University, Stanford, California, United States of America
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - John M. Colford
- Division of Epidemiology & Biostatistics, University of California, Berkeley, Berkeley, California, United States of America
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Gerber M, Ayekoé SA, Beckmann J, Bonfoh B, Coulibaly JT, Daouda D, du Randt R, Finda L, Gall S, Mollel GJ, Lang C, Long KZ, Ludyga S, Masanja H, Müller I, Nqweniso S, Okumu F, Probst-Hensch N, Pühse U, Steinmann P, Traoré SG, Walter C, Utzinger J. Effects of school-based physical activity and multi-micronutrient supplementation intervention on growth, health and well-being of schoolchildren in three African countries: the KaziAfya cluster randomised controlled trial protocol with a 2 × 2 factorial design. Trials 2020; 21:22. [PMID: 31907019 DOI: 10.1186/s13063-13019-13883-13065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/05/2019] [Indexed: 05/29/2023] Open
Abstract
BACKGROUND In low- and middle-income countries, infectious diseases remain a key public health issue. Additionally, non-communicable diseases are a rapidly growing public health problem that impose a considerable burden on population health. One way to address this dual disease burden, is to incorporate (lifestyle) health promotion measures within the education sector. In the planned study, we will (i) assess and compare physical activity, physical fitness, micronutrient status, body composition, infections with soil-transmitted helminths, Schistosoma mansoni, malaria, inflammatory and cardiovascular health risk markers, cognitive function, health-related quality of life, and sleep in schoolchildren in Côte d'Ivoire, South Africa and Tanzania. We will (ii) determine the bi- and multivariate associations between these variables and (iii) examine the effects of a school-based health intervention that consists of physical activity, multi-micronutrient supplementation, or both. METHODS Assuming that no interaction occurs between the two interventions (physical activity and multi-micronutrient supplementation), the study is designed as a cluster-randomised, placebo-controlled trial with a 2 × 2 factorial design. Data will be obtained at three time points: at baseline and at 9 months and 21 months after the baseline assessment. In each country, 1320 primary schoolchildren from grades 1-4 will be recruited. In each school, classes will be randomly assigned to one of four interventions: (i) physical activity; (ii) multi-micronutrient supplementation; (iii) physical activity plus multi-micronutrient supplementation; and (iv) no intervention, which will serve as the control. A placebo product will be given to all children who do not receive multi-micronutrient supplementation. After obtaining written informed consent from the parents/guardians, the children will be subjected to anthropometric, clinical, parasitological and physiological assessments. Additionally, fitness tests will be performed, and children will be invited to wear an accelerometer device for 7 days to objectively assess their physical activity. Children infected with S. mansoni and soil-transmitted helminths will receive deworming drugs according to national policies. Health and nutrition education will be provided to the whole study population independently of the study arm allocation. DISCUSSION The study builds on the experience and lessons of a previous study conducted in South Africa. It involves three African countries with different social-ecological contexts to investigate whether results are generalisable across the continent. TRIAL REGISTRATION The study was registered on August 9, 2018, with ISRCTN. https://doi.org/10.1186/ISRCTN29534081.
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Affiliation(s)
- Markus Gerber
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland.
| | - Serge A Ayekoé
- Institut National de la Jeunesse et des Sports, Abidjan, Côte d'Ivoire
| | - Johanna Beckmann
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Bassirou Bonfoh
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Jean T Coulibaly
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
| | - Dao Daouda
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Rosa du Randt
- Nelson Mandela University, Port Elizabeth, South Africa
| | - Lina Finda
- Ifakara Health Institute, Dar es Salaam/Ifakara, Tanzania
| | - Stefanie Gall
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | | | - Christin Lang
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Kurt Z Long
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sebastian Ludyga
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | | | - Ivan Müller
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | | | - Fredros Okumu
- Ifakara Health Institute, Dar es Salaam/Ifakara, Tanzania
| | - Nicole Probst-Hensch
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Uwe Pühse
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Peter Steinmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sylvain G Traoré
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
- Unité de Formation et de Recherche des Sciences et Technologies des Aliments, Université Nangui Abrogoua, Abidjan, Côte d'Ivoire
| | - Cheryl Walter
- Nelson Mandela University, Port Elizabeth, South Africa
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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21
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Ayana M, Cools P, Mekonnen Z, Biruksew A, Dana D, Rashwan N, Prichard R, Vlaminck J, Verweij JJ, Levecke B. Comparison of four DNA extraction and three preservation protocols for the molecular detection and quantification of soil-transmitted helminths in stool. PLoS Negl Trop Dis 2019; 13:e0007778. [PMID: 31658264 PMCID: PMC6837582 DOI: 10.1371/journal.pntd.0007778] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 11/07/2019] [Accepted: 09/12/2019] [Indexed: 12/27/2022] Open
Abstract
Background A DNA extraction and preservation protocol that yields sufficient and qualitative DNA is pivotal for the success of any nucleic acid amplification test (NAAT), but it still poses a challenge for soil-transmitted helminths (STHs), including Ascaris lumbricoides, Trichuris trichiura and the two hookworms (Necator americanus and Ancylostoma duodenale). In the present study, we assessed the impact of different DNA extraction and preservativation protocols on STH-specific DNA amplification from stool. Methodology and principal findings In a first experiment, DNA was extracted from 37 stool samples with variable egg counts for T. trichiura and N. americanus applying two commercial kits, both with and without a prior bead beating step. The DNA concentration of T. trichiura and N. americanus was estimated by means of qPCR. The results showed clear differences in DNA concentration across both DNA extraction kits, which varied across both STHs. They also indicated that adding a bead beating step substantially improved DNA recovery, particularly when the FECs were high. In a second experiment, 20 stool samples with variable egg counts for A. lumbricoides, T. trichiura and N. americanus were preserved in either 96% ethanol, 5% potassium dichromate or RNAlater and were stored at 4°C for 65, 245 and 425 days. DNA was extracted using the DNeasy Blood & Tissue kit with a bead beating step. Stool samples preserved in ethanol proved to yield higher DNA concentrations as FEC increased, although stool samples appeared to be stable over time in all preservatives. Conclusions The choice of DNA extraction kit significantly affects the outcome of NAATs. Given the clear benefit of bead beating and our validation of ethanol for (long-term) preservation, we recommend that these aspects of the protocol should be adopted by any stool sampling and DNA extraction protocol for downstream NAAT-based detection and quantification of STHs. DNA-based tools are increasingly being used for the diagnosis of intestinal worm infections in both clinical and research laboratories. However, recovering DNA from intestinal worm eggs in stool remains a challenge since this DNA is protected by a very rigid egg shell. Furthermore, stool contains inhibitors that can affect test results and these should be removed during DNA extraction. Prior to DNA extraction, samples are often preserved, but the impact of the type of preservatives and the duration of preservation remains poorly studied. In the present study, we assessed the impact of four DNA extraction and three preservation protocols on the downstream performance of a DNA-based diagnostic tool for intestinal worms. We found significant differences in DNA recovery across the DNA and preservation protocols, but DNA from worm eggs in stool proved to be stable over time in all preservatives.
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Affiliation(s)
- Mio Ayana
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Ghent, Belgium
| | - Piet Cools
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Ghent, Belgium
| | - Zeleke Mekonnen
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Abdissa Biruksew
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Daniel Dana
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Ghent, Belgium
| | - Nour Rashwan
- Institute of Parasitology, McGill University, Montreal, Quebec, Canada
| | - Roger Prichard
- Institute of Parasitology, McGill University, Montreal, Quebec, Canada
| | - Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Ghent, Belgium
| | - Jaco J. Verweij
- Laboratory for Medical Microbiology and Immunology, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Ghent, Belgium
- * E-mail:
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22
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Papaiakovou M, Wright J, Pilotte N, Chooneea D, Schär F, Truscott JE, Dunn JC, Gardiner I, Walson JL, Williams SA, Littlewood DTJ. Pooling as a strategy for the timely diagnosis of soil-transmitted helminths in stool: value and reproducibility. Parasit Vectors 2019; 12:443. [PMID: 31522691 PMCID: PMC6745781 DOI: 10.1186/s13071-019-3693-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The strategy of pooling stool specimens has been extensively used in the field of parasitology in order to facilitate the screening of large numbers of samples whilst minimizing the prohibitive cost of single sample analysis. The aim of this study was to develop a standardized reproducible pooling protocol for stool samples, validated between two different laboratories, without jeopardizing the sensitivity of the quantitative polymerase chain reaction (qPCR) assays employed for the detection of soil-transmitted helminths (STHs). Two distinct experimental phases were recruited. First, the sensitivity and specificity of the established protocol was assessed by real-time PCR for each one of the STHs. Secondly, agreement and reproducibility of the protocol between the two different laboratories were tested. The need for multiple stool sampling to avoid false negative results was also assessed. Finally, a cost exercise was conducted which included labour cost in low- and high-wage settings, consumable cost, prevalence of a single STH species, and a simple distribution pattern of the positive samples in pools to estimate time and money savings suggested by the strategy. RESULTS The sensitivity of the pooling method was variable among the STH species but consistent between the two laboratories. Estimates of specificity indicate a 'pooling approach' can yield a low frequency of 'missed' infections. There were no significant differences regarding the execution of the protocol and the subsequent STH detection between the two laboratories, which suggests in most cases the protocol is reproducible by adequately trained staff. Finally, given the high degree of agreement, there appears to be little or no need for multiple sampling of either individuals or pools. CONCLUSIONS Our results suggest that the pooling protocol developed herein is a robust and efficient strategy for the detection of STHs in 'pools-of-five'. There is notable complexity of the pool preparation to ensure even distribution of helminth DNA throughout. Therefore, at a given setting, cost of labour among other logistical and epidemiological factors, is the more concerning and determining factor when choosing pooling strategies, rather than losing sensitivity and/or specificity of the molecular assay or the method.
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Affiliation(s)
- Marina Papaiakovou
- Department of Life Sciences, Natural History Museum, London, UK.
- Department of Biological Sciences, Smith College, Northampton, MA, USA.
| | - James Wright
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
- The Hospital for Sick Children, Toronto, ON, Canada
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, MA, USA
- Molecular and Cellular Biology Programme, University of Massachusetts, Amherst, MA, USA
| | - Darren Chooneea
- Core Research Laboratories, Natural History Museum, London, UK
| | | | - James E Truscott
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Julia C Dunn
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | | | - Judd L Walson
- DeWorm3, Natural History Museum, London, UK
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, MA, USA
- Molecular and Cellular Biology Programme, University of Massachusetts, Amherst, MA, USA
| | - D Timothy J Littlewood
- Department of Life Sciences, Natural History Museum, London, UK
- DeWorm3, Natural History Museum, London, UK
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23
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Yang A, Bakhtari N, Langdon-Embry L, Redwood E, Grandjean Lapierre S, Rakotomanga P, Rafalimanantsoa A, De Dios Santos J, Vigan-Womas I, Knoblauch AM, Marcos LA. Kankanet: An artificial neural network-based object detection smartphone application and mobile microscope as a point-of-care diagnostic aid for soil-transmitted helminthiases. PLoS Negl Trop Dis 2019; 13:e0007577. [PMID: 31381573 PMCID: PMC6695198 DOI: 10.1371/journal.pntd.0007577] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 08/15/2019] [Accepted: 06/25/2019] [Indexed: 12/20/2022] Open
Abstract
Background Endemic areas for soil-transmitted helminthiases often lack the tools and trained personnel necessary for point-of-care diagnosis. This study pilots the use of smartphone microscopy and an artificial neural network-based (ANN) object detection application named Kankanet to address those two needs. Methodology/Principal findings A smartphone was equipped with a USB Video Class (UVC) microscope attachment and Kankanet, which was trained to recognize eggs of Ascaris lumbricoides, Trichuris trichiura, and hookworm using a dataset of 2,078 images. It was evaluated for interpretive accuracy based on 185 new images. Fecal samples were processed using Kato-Katz (KK), spontaneous sedimentation technique in tube (SSTT), and Merthiolate-Iodine-Formaldehyde (MIF) techniques. UVC imaging and ANN interpretation of these slides was compared to parasitologist interpretation of standard microscopy.Relative to a gold standard defined as any positive result from parasitologist reading of KK, SSTT, and MIF preparations through standard microscopy, parasitologists reading UVC imaging of SSTT achieved a comparable sensitivity (82.9%) and specificity (97.1%) in A. lumbricoides to standard KK interpretation (97.0% sensitivity, 96.0% specificity). The UVC could not accurately image T. trichiura or hookworm. Though Kankanet interpretation was not quite as sensitive as parasitologist interpretation, it still achieved high sensitivity for A. lumbricoides and hookworm (69.6% and 71.4%, respectively). Kankanet showed high sensitivity for T. trichiura in microscope images (100.0%), but low in UVC images (50.0%). Conclusions/Significance The UVC achieved comparable sensitivity to standard microscopy with only A. lumbricoides. With further improvement of image resolution and magnification, UVC shows promise as a point-of-care imaging tool. In addition to smartphone microscopy, ANN-based object detection can be developed as a diagnostic aid. Though trained with a limited dataset, Kankanet accurately interprets both standard microscope and low-quality UVC images. Kankanet may achieve sensitivity comparable to parasitologists with continued expansion of the image database and improvement of machine learning technology. For rainforest-enshrouded rural villages of Madagascar, soil-transmitted helminthiases are more the rule than the exception. However, the microscopy equipment and lab technicians needed for diagnosis are a distance of several days’ hike away. We piloted a solution for these communities by leveraging resources the villages already had: a traveling team of local health care workers, and their personal Android smartphones. We demonstrated that an inexpensive, commercially available microscope attachment for smartphones could rival the sensitivity and specificity of a regular microscope using standard field fecal sample processing techniques. We also developed an artificial neural network-based object detection Android application, called Kankanet, based on open-source programming libraries. Kankanet was used to detect eggs of the three most common soil-transmitted helminths: Ascaris lumbricoides, Trichuris trichiura, and hookworm. We found Kankanet to be moderately sensitive and highly specific for both standard microscope images and low-quality smartphone microscope images. This proof-of-concept study demonstrates the diagnostic capabilities of artificial neural network-based object detection systems. Since the programming frameworks used were all open-source and user-friendly even for computer science laymen, artificial neural network-based object detection shows strong potential for development of low-cost, high-impact diagnostic aids essential to health care and field research in resource-limited communities.
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Affiliation(s)
- Ariel Yang
- School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
| | - Nahid Bakhtari
- School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
| | - Liana Langdon-Embry
- School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
| | - Emile Redwood
- School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
| | - Simon Grandjean Lapierre
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
- Immunopathology axis, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
- Mycobacteria Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | | | | | | | - Inès Vigan-Womas
- Immunology of Infectious Diseases Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Astrid M. Knoblauch
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
- Mycobacteria Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Luis A. Marcos
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
- Department of Medicine, Stony Brook University, New York, United States of America
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Vlaminck J, Cools P, Albonico M, Ame S, Ayana M, Cringoli G, Dana D, Keiser J, Maurelli MP, Matoso LF, Montresor A, Mekonnen Z, Mirams G, Corrêa-Oliveira R, Pinto SA, Rinaldi L, Sayasone S, Thomas E, Vercruysse J, Verweij JJ, Levecke B. Therapeutic efficacy of albendazole against soil-transmitted helminthiasis in children measured by five diagnostic methods. PLoS Negl Trop Dis 2019; 13:e0007471. [PMID: 31369562 PMCID: PMC6675043 DOI: 10.1371/journal.pntd.0007471] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/16/2019] [Indexed: 01/15/2023] Open
Abstract
Background Preventive chemotherapy (PC) with benzimidazole drugs is the backbone of soil-transmitted helminth (STH) control programs. Over the past decade, drug coverage has increased and with it, the possibility of developing anthelmintic resistance. It is therefore of utmost importance to monitor drug efficacy. Currently, a variety of novel diagnostic methods are available, but it remains unclear whether they can be used to monitor drug efficacy. In this study, we compared the efficacy of albendazole (ALB) measured by different diagnostic methods in a head-to-head comparison to the recommended single Kato-Katz. Methods An ALB efficacy trial was performed in 3 different STH-endemic countries (Ethiopia, Lao PDR and Tanzania), each with a different PC-history. During these trials, stool samples were evaluated with Kato-Katz (single and duplicate), Mini-FLOTAC, FECPAKG2, and qPCR. The reduction rate in mean eggs per gram of stool (ERR) and mean genome equivalents / ml of DNA extract (GERR) were calculated to estimate drug efficacy. Principal findings and conclusions The results of the efficacy trials showed that none of the evaluated diagnostic methods could provide reduction rates that were equivalent to a single Kato-Katz for all STH. However, despite differences in clinical sensitivity and egg counts, they agreed in classifying efficacy according to World Health Organization (WHO) guidelines. This demonstrates that diagnostic methods for assessing drug efficacy should be validated with their intended-use in mind and that other factors like user-friendliness and costs will likely be important factors in driving the choice of diagnostics. In addition, ALB efficacy against STH infections was lower in sites with a longer history of PC. Yet, further research is needed to identify factors that contribute to this finding and to verify whether reduced efficacy can be associated with mutations in the β-tubulin gene that have previously been linked to anthelmintic resistance. Trial registration ClinicalTrials.gov NCT03465488. During the last decade, the scale of deworming programs that aim to eliminate the morbidity caused by intestinal worms has increased to a level that is unprecedented in history. It is therefore of utmost importance to monitor any change in therapeutic efficacy that may arise from emerging drug resistance. Currently, a variety of novel methods have been described, but it remains unclear whether they can be used for monitoring drug efficacy. We applied different diagnostic methods to measure the efficacy of a commonly administered drug in deworming programs in 3 countries with different historical exposure to deworming programs. Compared to the standard diagnostic method, all diagnostic methods revealed good agreement in classifying the therapeutic efficacy according to World Health Organization guidelines, despite clear differences in diagnostic performance. We also noticed that the drug efficacy was lower in countries where drug pressure has been high. However, more research is necessary to identify factors that explain this variation in drug efficacy, including but not limited to the frequency in mutations in genes that are known to be linked with anthelmintic resistance.
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Affiliation(s)
- Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Piet Cools
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Marco Albonico
- Center for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Negrar, Italy
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Shaali Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | - Mio Ayana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Daniel Dana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Maria P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Leonardo F. Matoso
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
- Nursing school, Federal University of Minas Gerais, Brazil
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Zeleke Mekonnen
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | | | - Rodrigo Corrêa-Oliveira
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Simone A. Pinto
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Somphou Sayasone
- Lao Tropical and Public Health Institute, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | | | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Jaco J. Verweij
- Laboratory for Medical Microbiology and Immunology, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
- * E-mail:
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Cools P, Vlaminck J, Albonico M, Ame S, Ayana M, José Antonio BP, Cringoli G, Dana D, Keiser J, Maurelli MP, Maya C, Matoso LF, Montresor A, Mekonnen Z, Mirams G, Corrêa-Oliveira R, Pinto SA, Rinaldi L, Sayasone S, Thomas E, Verweij JJ, Vercruysse J, Levecke B. Diagnostic performance of a single and duplicate Kato-Katz, Mini-FLOTAC, FECPAKG2 and qPCR for the detection and quantification of soil-transmitted helminths in three endemic countries. PLoS Negl Trop Dis 2019; 13:e0007446. [PMID: 31369558 PMCID: PMC6675048 DOI: 10.1371/journal.pntd.0007446] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/07/2019] [Indexed: 12/20/2022] Open
Abstract
Background Because the success of deworming programs targeting soil-transmitted helminths (STHs) is evaluated through the periodically assessment of prevalence and infection intensities, the use of the correct diagnostic method is of utmost importance. The STH community has recently published for each phase of a deworming program the minimal criteria that a potential diagnostic method needs to meet, the so-called target product profiles (TPPs). Methodology We compared the diagnostic performance of a single Kato-Katz (reference method) with that of other microscopy-based methods (duplicate Kato-Katz, Mini-FLOTAC and FECPAKG2) and one DNA-based method (qPCR) for the detection and quantification of STH infections in three drug efficacy trials in Ethiopia, Lao PDR, and Tanzania. Furthermore, we evaluated a selection of minimal diagnostic criteria of the TPPs. Principal findings All diagnostic methods showed a clinical sensitivity of ≥90% for all STH infections of moderate-to-heavy intensities. For infections of very low intensity, only qPCR resulted in a sensitivity that was superior to a single Kato-Katz for all STHs. Compared to the reference method, both Mini-FLOTAC and FECPAKG2 resulted in significantly lower fecal egg counts for some STHs, leading to a substantial underestimation of the infection intensity. For qPCR, there was a positive significant correlation between the egg counts of a single Kato-Katz and the DNA concentration. Conclusions/Significance Our results indicate that the diagnostic performance of a single Kato-Katz is underestimated by the community and that diagnostic specific thresholds to classify intensity of infection are warranted for Mini-FLOTAC, FECPAKG2 and qPCR. When we strictly apply the TPPs, Kato-Katz is the only microscopy-based method that meets the minimal diagnostic criteria for application in the planning, monitoring and evaluation phase of an STH program. qPCR is the only method that could be considered in the phase that aims to seek confirmation for cessation of program. Trial registration ClinicalTrials.gov NCT03465488 To control the burden caused by intestinal worms, the World Health Organization recommends large-scale deworming programs where anti-worm drugs are administered to at-risk populations. The decision to scale down drug distribution is based on the periodically assessment of prevalence and intensity of infections using a standard diagnostic method. Today, the scientific community strongly doubts whether this method can be used throughout the program. This is in particular when it fails to detect infections of low intensity, and hence may result in prematurely stopping the distribution of drugs. We compared the diagnostic performance of alternative diagnostic methods in three drug efficacy trials in two African and one Asian country. The diagnostic methods were based on demonstration of worm eggs or worm DNA in stool. We also checked the results with minimal diagnostic criteria which have been recently been proposed by the scientific community. Our results indicate that of all diagnostic methods based on demonstration of worm eggs, only the current standard method fulfills the diagnostic criteria for planning, monitoring and evaluation phases of deworming program. Furthermore, we showed that DNA-based methods could be considered in the phase that aims to seek confirmation for cessation of the deworming program.
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Affiliation(s)
- Piet Cools
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Marco Albonico
- Center for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Negrar, Italy
- Department of Life Sciences and Systems Biology, University of Turin, Italy
| | - Shaali Ame
- Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | - Mio Ayana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | | | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Daniel Dana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Maria P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Catalina Maya
- Engineering Institute of National Autonomous University of Mexico, Mexico City, Mexico
| | - Leonardo F. Matoso
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Zeleke Mekonnen
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | | | - Rodrigo Corrêa-Oliveira
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Simone A. Pinto
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Somphou Sayasone
- Lao Tropical and Public Health Institute, Ministry of Health, Vientiane, Lao People’s Democratic Republic
| | | | - Jaco J. Verweij
- Laboratory for Medical Microbiology and Immunology, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
- * E-mail:
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Giardina F, Coffeng LE, Farrell SH, Vegvari C, Werkman M, Truscott JE, Anderson RM, de Vlas SJ. Sampling strategies for monitoring and evaluation of morbidity targets for soil-transmitted helminths. PLoS Negl Trop Dis 2019; 13:e0007514. [PMID: 31242194 PMCID: PMC6615707 DOI: 10.1371/journal.pntd.0007514] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 07/09/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022] Open
Abstract
Background The current World Health Organization (WHO) target for the three major soil-transmitted helminth (STH) infections is to reduce prevalence of moderate-to-heavy infections to below 1% by 2020. In terms of monitoring and evaluation (M&E), the current WHO guidelines for control of STHs recommend evaluation of infection levels in school-age children (SAC) after five to six years of preventive chemotherapy (PC), using the standard Kato-Katz faecal smear. Here, we assess the predictive performance of various sampling designs for the evaluation of the morbidity target. Methodology/Principal findings Using two mathematical models for STH transmission and control, we simulate how the number of villages and SAC sampled affect the ability of survey results in sentinel villages to predict the achievement of the morbidity target in PC implementation units (e.g. districts). As PC is stopped when the prevalence of infection in SAC in sentinel villages is less than 1%, we estimate the positive predictive value (PPV) of this indicator for meeting the morbidity target in the whole district. The PPV varies by species and PC strategy, and it is generally higher in areas with lower pre-control prevalence. Sampling a fixed number of SAC spread out over 10 instead of 5 sentinel villages may increase the PPV by up to 20 percentage points. If every SAC in a village is tested, a higher number of villages may increase the PPV by up to 80 percentage points. Increasing the proportion of SAC tested per village does not result in a relevant increase of PPV. Conclusions/Significance Although the WHO guidelines provide a combined strategy to control the three STH species, the efficacy of PC strategies clearly differs by species. There is added value in considering more villages within implementation units for M&E of morbidity targets, the extent varying by STH species. A better understanding of pre- and post-control local STH prevalence levels is essential for an adequate M&E strategy including the definition of morbidity targets at the appropriate geographical scale. Soil-transmitted helminths (STHs) affect approximately 1.5 billion people worldwide. The World Health Organization target for STHs is to achieve <1% prevalence of moderate-to-heavy infections among school-age children (SAC) through preventive chemotherapy (PC) with albendazole or mebendazole. For monitoring and evaluation (M&E) of STH infections, it is recommended to assess the infection levels in SAC after five to six years of treatment and to stop PC if the prevalence of infection is <1%. In this study, we use two mathematical models to assess the predictive performance of different sampling designs for the evaluation of the morbidity target. We find that the efficacy of PC strategies differs significantly by species and pre-control infection levels. Achieving 1% prevalence of infection in sentinel villages may still imply a prevalence of moderate-to-heavy infections >1% in the entire PC implementation unit. Evaluating the prevalence of any infection over a higher number of sentinel villages improves the accuracy in assessing the morbidity target at the implementation unit level, even when a lower proportion of SAC per village is tested. A better understanding of pre- and post-control local STH prevalence levels through large scale data collection is essential for the definition of an adequate M&E strategy for STH control.
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Affiliation(s)
- Federica Giardina
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- * E-mail:
| | - Luc E. Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Sam H. Farrell
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Carolin Vegvari
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Marleen Werkman
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - James E. Truscott
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - Roy M. Anderson
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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Stracke K, Clarke N, Awburn CV, Vaz Nery S, Khieu V, Traub RJ, Jex AR. Development and validation of a multiplexed-tandem qPCR tool for diagnostics of human soil-transmitted helminth infections. PLoS Negl Trop Dis 2019; 13:e0007363. [PMID: 31206520 PMCID: PMC6597125 DOI: 10.1371/journal.pntd.0007363] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 06/27/2019] [Accepted: 04/05/2019] [Indexed: 11/30/2022] Open
Abstract
Soil-transmitted helminths (STH) are a major cause of morbidity in tropical developing countries with a global infection prevalence of more than one billion people and disease burden of around 3.4 million disability adjusted life years. Infection prevalence directly correlates to inadequate sanitation, impoverished conditions and limited access to public health systems. Underestimation of infection prevalence using traditional microscopy-based diagnostic techniques is common, specifically in populations with access to benzimidazole mass treatment programs and a predominance of low intensity infections. In this study, we developed a multiplexed-tandem qPCR (MT-PCR) tool to identify and quantify STH eggs in stool samples. We have assessed this assay by measuring infection prevalence and intensity in field samples of two cohorts of participants from Timor-Leste and Cambodia, which were collected as part of earlier epidemiological studies. MT-PCR diagnostic parameters were compared to a previously published multiplexed qPCR for STH detection. The MT-PCR assay agreed strongly with qPCR data and showed a diagnostic specificity of 99.60–100.00% (sensitivity of 83.33–100.00%) compared to qPCR and kappa agreement exceeding 0.85 in all tests. In addition, the MT-PCR has the added advantage of distinguishing Ancylostoma spp. species, namely Ancylostoma duodenale and Ancylostoma ceylanicum. This semi-automated platform uses a standardized, manufactured reagent kit, shows excellent run-to-run consistency/repeatability and supports high-throughput detection and quantitation at a moderate cost. Soil-transmitted helminthiases are among the most prevalent and damaging neglected tropical diseases and have a significant global health impact. Accurate identification and quantitation of STH infection is a cornerstone of effective control. Direct observation and counting of eggs in faeces is the current gold-standard method for diagnosis of infection. This approach is time consuming and has poor sensitivity. As ongoing oral benzimidazole therapy across many endemic regions leads to a reduction in STH prevalence and intensity, these sensitivity limitations become an increasingly relevant issue, particularly with respect to monitoring treatment efficacy, identifying reductions in parasite transmission, and accurately quantifying infection burden in discrete populations in middle-income countries. PCR-based detection has long been proposed as an alternative approach to STH diagnosis and many protocols, including quantitative PCR-based methods, have been developed. However, these methods are largely bespoke and use non-standardized reagents that can greatly impact on the transferability and relative consistency of their performance. In the current study, we evaluate an automated, commercially-produced molecular diagnostic tool for validation of the major soil-transmitted helminths, including Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale and Ancylostoma ceylanicum, and evaluate its performance in comparison to an established multiplexed qPCR using faecal samples from endemic settings.
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Affiliation(s)
- Katharina Stracke
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
| | - Naomi Clarke
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory, Australia
- Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Camille V. Awburn
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - Susana Vaz Nery
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory, Australia
- Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Virak Khieu
- National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Rebecca J. Traub
- Faculty for Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Aaron R. Jex
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Faculty for Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
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Mubanga C, Mwape KE, Phiri IK, Trevisan C, Zulu G, Chabala C, van Damme I, Schmidt V, Dorny P, Gabriël S. Progress on the development of rapid diagnostic tests for foodborne neglected zoonotic helminthiases: A systematic review. Acta Trop 2019; 194:135-147. [PMID: 30946810 DOI: 10.1016/j.actatropica.2019.03.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/15/2019] [Accepted: 03/31/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND Foodborne Neglected Zoonotic Helminths (FNZH) are parasites of both economic and public health importance. They include Taenia solium, Echinococcus granulosus sensu lato, Echinococcus multilocularis and Foodborne trematodes (FBT). FNZH are earmarked for major interventions for control, elimination and eradication. This systematic review highlights the progress towards development of rapid tests for the diagnosis of FNZH since 2010 when they were listed as neglected tropical diseases. METHODOLOGY A systematic search was conducted in three databases, World of Science, Embase and PubMed using the same search phrase. The search produced 480 hits. Three studies from back referencing were included. Only 22 of these met the inclusion criteria. Data was extracted from these and presented qualitatively. RESULTS Twenty-five rapid diagnostic tests were found to have been developed since 2010, eight for diagnosis of T. solium infections, eight for echinococcosis and nine for FBT infections. The rapid tests for diagnosing T. solium infections included six antibody detecting and two antigen detecting tests. They constitute a combination among them, with some tests providing qualitative, others quantitative results. Similarly, seven out of the eight rapid tests developed for Echinococcus infections were antibody detecting tests save for one loop mediated isothermal amplification test. All of them were qualitative tests. For FBT infections, nine rapid tests were described; two antibody and one nucleic acid detecting test for diagnosis of Fascioliasis; three nucleic acid detecting tests for Opisthorchiasis; one antibody detecting test for Paragonimiasis; and for Clonorchiasis, one antibody and one nucleic acid detecting test. The FBT infection rapid tests were all qualitative in nature. Most of these tests have not undergone field evaluation in endemic areas where they will be used most. CONCLUSION This review describes the development and evaluation of rapid diagnostic tests, while highlighting the need for in depth validations of the tools to determine how well they can perform in endemic areas.
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Affiliation(s)
- Chishimba Mubanga
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia.
| | - Kabemba E Mwape
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Isaac K Phiri
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Chiara Trevisan
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Gideon Zulu
- Provincial Medical Office, Ministry of Health, Kasama, Zambia
| | - Chishala Chabala
- Children's Hospital, University Teaching Hospitals, Lusaka, Zambia
| | - Inge van Damme
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Veronika Schmidt
- Centre for Global Health, Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany; Centre for Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
| | - Pierre Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Sarah Gabriël
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Storey HL, Agarwal N, Cantera J, Golden A, Gallo K, Herrick T, Belizario V, Kihara J, Mwandawiro C, Cadwallader B, de los Santos T. Formative research to inform development of a new diagnostic for soil-transmitted helminths: Going beyond the laboratory to ensure access to a needed product. PLoS Negl Trop Dis 2019; 13:e0007372. [PMID: 31150389 PMCID: PMC6561600 DOI: 10.1371/journal.pntd.0007372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 06/12/2019] [Accepted: 04/09/2019] [Indexed: 12/11/2022] Open
Abstract
Soil-transmitted helminths (STHs) affect more than 1.5 billion people. The global strategy to control STH infections requires periodic mass drug administration (MDA) based on prevalence among populations at risk determined by diagnostic testing. Widely used copromicroscopy methods to detect infection, however, have low sensitivity as the prevalence and intensity of STH infections decline with repeated MDA. More sensitive diagnostic tools are needed to inform program decision-making. Using an integrated product development process, PATH conducted qualitative and quantitative formative research to inform the design and development of a more sensitive test for STH infections. The research, grounded in a conceptual framework for ensuring access to health products, involved stakeholder analysis, key opinion leader interviews, observational site visits of ongoing STH surveillance programs, and market research including market sizing, costing and willingness-to-pay analyses. Stakeholder analysis identified key groups and proposed strategic engagement of stakeholders during product development. Interviews highlighted features, motivations and concerns that are important for guiding design and implementation of new STH diagnostics. Process mapping outlined current STH surveillance workflows in Kenya and the Philippines. Market sizing in 2016 was estimated around half a million tests for lower STH burden countries, and 1-2 million tests for higher STH burden countries. The cost of commodities per patient for a molecular STH diagnostic may be around $10, 3-4 times higher than copromicroscopy methods, though savings may be possible in time and staffing requirements. The market is highly price sensitive as even at $5 per test, only 27% of respondents thought the test would be used by surveillance programs. A largely subsidized STH control strategy and a semi-functional Kato-Katz test may have created few incentives for manufacturers to innovate in STH diagnostics. Diverse partnerships, as well as balancing needs and expectations for new STH diagnostics are necessary to ensure access to needed products.
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Affiliation(s)
- Helen L. Storey
- PATH, Seattle, Washington, United States of America
- * E-mail:
| | - Neha Agarwal
- PATH, Seattle, Washington, United States of America
| | | | | | - Kerry Gallo
- PATH, Seattle, Washington, United States of America
| | - Tara Herrick
- PATH, Seattle, Washington, United States of America
| | | | - Jimmy Kihara
- Kenya Medical Research Institute, Nairobi, Kenya
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30
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Papaiakovou M, Gasser RB, Littlewood DTJ. Quantitative PCR-Based Diagnosis of Soil-Transmitted Helminth Infections: Faecal or Fickle? Trends Parasitol 2019; 35:491-500. [PMID: 31126720 DOI: 10.1016/j.pt.2019.04.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/16/2019] [Accepted: 04/19/2019] [Indexed: 11/19/2022]
Abstract
Treatment and control programmes tackling soil-transmitted helminth (STH) infections require sensitive, reliable, and accurate diagnostic tools. There is a growing need for measures of infection intensity as programmes approach STH control. Quantitative real-time PCR (qPCR) is well suited to the detection of DNA targets present in stool, even in low-prevalence settings. Detecting low levels of infection becomes increasingly important when the breakpoint of transmission is approached, and is vital when monitoring for recrudescence once control, or possibly 'elimination', is achieved. We address key challenges and questions that remain as barriers to incorporating qPCR as a cornerstone diagnostic tool for STH infections.
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Affiliation(s)
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
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Fernández-Rivas G, Rivaya B, Romaní N, Hao Wang J, Alcaide M, Matas L. Diagnosis of soil-transmitted helminth infections. An unsolved problemin the omics era. Enferm Infecc Microbiol Clin 2019; 37 Suppl 1:20-25. [PMID: 31138419 DOI: 10.1016/s0213-005x(19)30178-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Infections caused by Strongyloides stercoralis and other soil-transmitted worms such as hookworms (Necator americanus and Ancylostoma duodenale) represent a major problem worldwide, especially in developing areas. They are difficult to suspect clinically since they produce non-specific and often overlapping signs and symptoms. Likewise, their long prepatent periods hamper the detection of parasitic structures. Microscopic diagnosis is still the most commonly used tool in healthcare laboratories but it is still far from being the ideal technique to detect these infections due to its low sensitivity. In addition, these nematodes have strong morphologic similarities and consequently microbiological diagnosis remains a challenge. Serology has made progress in the diagnosis of S. stercoralis infection but this option is not yet available for hookworms. Molecular biology techniques have been shown to slightly increase this lack of sensitivity, but as with other parasitic infections, they are not currently available for use in clinical microbiology laboratories. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016», which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.
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Affiliation(s)
- Gema Fernández-Rivas
- Departamento de Genética y Microbiología, Universitat Autònoma de Barcelona, Barcelona, España.
| | - Belén Rivaya
- Departamento de Genética y Microbiología, Universitat Autònoma de Barcelona, Barcelona, España
| | - Nona Romaní
- Departamento de Genética y Microbiología, Universitat Autònoma de Barcelona, Barcelona, España
| | - Jun Hao Wang
- Departamento de Genética y Microbiología, Universitat Autònoma de Barcelona, Barcelona, España
| | - Mireya Alcaide
- Departamento de Genética y Microbiología, Universitat Autònoma de Barcelona, Barcelona, España
| | - Lurdes Matas
- Departamento de Genética y Microbiología, Universitat Autònoma de Barcelona, Barcelona, España
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Muslim A, Mohd Sofian S, Shaari SA, Hoh BP, Lim YAL. Prevalence, intensity and associated risk factors of soil transmitted helminth infections: A comparison between Negritos (indigenous) in inland jungle and those in resettlement at town peripheries. PLoS Negl Trop Dis 2019; 13:e0007331. [PMID: 31009476 PMCID: PMC6497322 DOI: 10.1371/journal.pntd.0007331] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 05/02/2019] [Accepted: 03/25/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Formerly known as the Malaysian hunter gatherers, the Negrito Orang Asli (OA) were heavily dependent on the forest for sustenance and early studies indicated high prevalence of intestinal parasitism. Initiation of a redevelopment program in the 1970s aimed to demarginalize the OA was expected to reduce soil transmitted helminth (STH) infections. Gradually, the OA were relocated to new resettlement areas at the peripheries. The aim of this study was to compare STH infections between Negritos who are still living in the inland jungle with those living in resettlements. METHODOLOGY/PRINCIPAL FINDINGS A total of 416 Negrito participants were grouped into two categories of communities based on location; Inland Jungle Villages (IJV); and Resettlement Plan Scheme (RPS). Iodine wet mount, formalin-ether sedimentation, modified Trichrome and modified Ziehl-Neelsen staining and Kato-Katz methods were performed on stool samples. A questionnaire was used to collect information regarding demographic, socioeconomic, environmental and hygiene behaviors. Prevalence of STH was significantly higher in IJV (91.3%) versus RPS (83.1%) (P = 0.02). However, the percentage of individuals with severe intensity of Trichuris trichiura infections was significantly higher in the RPS (17.2%) compared to IJV (6.5%) (P = 0.01). Severe Ascaris lumbricoides infection was observed at 20.0% amongst RPS Negritos and 15.0% amongst IJV (P = 0.41). Whilst for hookworm infection, both prevalence and individuals with moderate to severe infections were higher in the IJV (26.2%, 41.0%) versus RPS (18.7%, 24.0%) (P values = 0.08, 0.09), accordingly. The prevalence other intestinal parasitic infections (e.g. Entamoeba sp., Blastocystis and flukes) was also higher in IJV versus RPS. Apart from poor hygienic behaviors as significant risk factors in both communities, low socio-economic status was highly associated with STH infections in RPS (P<0.001) but not significantly associated in IJV. CONCLUSIONS The findings showed that ex situ development plan by RPS has not profoundly contributed to the STH reduction among the OA. Conversely, burden rate of T. trichiura infections increased due to their extreme poverty and poor hygienic behaviors. Here, we are suggesting biannual mass albendazole intervention (triple dose regimens in RPS, but a single dose in IJV) and community empowerment to both communities. For a long-term and better uptake, these strategies must be done together with the community input and participation, respecting their traditional customs and accompanied by recruitment of more OA people in the health-care taskforce.
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Affiliation(s)
- Azdayanti Muslim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, Universiti Teknologi MARA (Sungai Buloh Campus) Sungai Buloh, Selangor, Malaysia
| | - Sakinah Mohd Sofian
- Institute of Medical Molecular Biotechnology (IMMB), Faculty of Medicine, Universiti Teknologi MARA (Sungai Buloh Campus), Sungai Buloh, Selangor, Malaysia
| | - Syahrul Azlin Shaari
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, Universiti Teknologi MARA (Sungai Buloh Campus) Sungai Buloh, Selangor, Malaysia
| | - Boon-Peng Hoh
- Faculty of Medicine & Health Sciences, UCSI University Kuala Lumpur Campus, Cheras, Kuala Lumpur, Malaysia
| | - Yvonne Ai-Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- Centre of Excellence for Research in AIDS (CERiA), University of Malaya, Kuala Lumpur, Malaysia
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Truscott JE, Dunn JC, Papaiakovou M, Schaer F, Werkman M, Littlewood DTJ, Walson JL, Anderson RM. Calculating the prevalence of soil-transmitted helminth infection through pooling of stool samples: Choosing and optimizing the pooling strategy. PLoS Negl Trop Dis 2019; 13:e0007196. [PMID: 30897089 PMCID: PMC6445468 DOI: 10.1371/journal.pntd.0007196] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 04/02/2019] [Accepted: 01/29/2019] [Indexed: 12/31/2022] Open
Abstract
Prevalence is a common epidemiological measure for assessing soil-transmitted helminth burden and forms the basis for much public-health decision-making. Standard diagnostic techniques are based on egg detection in stool samples through microscopy and these techniques are known to have poor sensitivity for individuals with low infection intensity, leading to poor sensitivity in low prevalence populations. PCR diagnostic techniques offer very high sensitivities even at low prevalence, but at a greater cost for each diagnostic test in terms of equipment needed and technician time and training. Pooling of samples can allow prevalence to be estimated while minimizing the number of tests performed. We develop a model of the relative cost of pooling to estimate prevalence, compared to the direct approach of testing all samples individually. Analysis shows how expected relative cost depends on both the underlying prevalence in the population and the size of the pools constructed. A critical prevalence level (approx. 31%) above which pooling is never cost effective, independent of pool size. When no prevalence information is available, there is no basis on which to choose between pooling and testing all samples individually. We recast our model of relative cost in a Bayesian framework in order to investigate how prior information about prevalence in a given population can be used to inform the decision to choose either pooling or full testing. Results suggest that if prevalence is below 10%, a relatively small exploratory prevalence survey (10-15 samples) can be sufficient to give a high degree of certainty that pooling may be relatively cost effective.
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Affiliation(s)
- James E. Truscott
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Julia C. Dunn
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Marina Papaiakovou
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Parasites & Vectors, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Fabian Schaer
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Parasites & Vectors, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Marleen Werkman
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - D. Timothy J. Littlewood
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Parasites & Vectors, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Judd L. Walson
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Parasites & Vectors, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Roy M. Anderson
- The DeWorm3 Project, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom
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Mutombo PN, Man NWY, Nejsum P, Ricketson R, Gordon CA, Robertson G, Clements ACA, Chacón-Fonseca N, Nissapatorn V, Webster JP, McLaws ML. Diagnosis and drug resistance of human soil-transmitted helminth infections: A public health perspective. Adv Parasitol 2019; 104:247-326. [PMID: 31030770 DOI: 10.1016/bs.apar.2019.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Soil-transmitted helminth (STH) infections represent a major public health problem globally, particularly among socio-economically disadvantaged populations. Detection of STH infections is often challenging, requiring a combination of diagnostic techniques to achieve acceptable sensitivity and specificity, particularly in low infection-intensity situations. The microscopy-based Kato-Katz remains the most widely used method but has low sensitivity in the detection of, for instance, Strongyloides spp. infections, among others. Antigen/antibody assays can be more sensitive but are parasite species-specific. Highly sensitive PCR methods have been developed to be multiplexed to allow multi-species detection. Novel diagnostic tests for all STH species are needed for effective monitoring, evaluation of chemotherapy programmes, and to assess the potential emergence of parasite resistance. This review discusses available diagnostic methods for the different stages of STH control programmes, which vary in sensitivity and spectrum of detection requirements, and tools to evaluate drug efficacy and resistance.
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Affiliation(s)
- Polydor Ngoy Mutombo
- School of Public Health and Community Medicine, UNSW Medicine, UNSW, Sydney, NSW, Australia; Centre for Biomedical Research, Burnet Institute, Melbourne, VIC, Australia.
| | - Nicola W Y Man
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
| | - Peter Nejsum
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
| | - Robert Ricketson
- Hale O'mana'o Biomedical Research, Division of Emerging Pathogens, Edmond, OK, United States
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Gemma Robertson
- Public and Environmental Health, Forensic and Scientific Services, Department of Health, Brisbane, QLD, Australia
| | | | - Nathalie Chacón-Fonseca
- Soil-Transmitted Helminths Section, Tropical Medicine Institute, Tropical Medicine Department, Faculty of Medicine, Central University of Venezuela, Caracas, Venezuela
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand; Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Nakhon Si Thammarat, Thailand
| | - Joanne P Webster
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | - Mary-Louise McLaws
- School of Public Health and Community Medicine, UNSW Medicine, UNSW, Sydney, NSW, Australia.
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Htun NSN, Odermatt P, Paboriboune P, Sayasone S, Vongsakid M, Phimolsarn-Nusith V, Tran XD, Ounnavong PS, Andriama-Hefasoa N, Senvanpan ND, Homsana A, Lianosay B, Xayavong D, Robinson DR, Bounsavath P, Prasayasith PP, Syphan SD, Lu YX, Thilakoun K, Xaiyaphet XS, Vongngakesone PT, Eze IC, Imboden M, Sripa B, Reinharz D, Probst-Hensch N. Association between helminth infections and diabetes mellitus in adults from the Lao People's Democratic Republic: a cross-sectional study. Infect Dis Poverty 2018; 7:105. [PMID: 30396368 PMCID: PMC6219195 DOI: 10.1186/s40249-018-0488-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/02/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND As a result of epidemiological transition, the health systems of low- and middle-income countries are increasingly faced with a dual disease burden of infectious diseases and emerging non-communicable diseases. Little is known about the mutual influence of these two disease groups. The aim of this study was to investigate the co-occurrence of helminth infections and diabetes mellitus in adults in Lao People's Democratic Republic (Lao PDR). METHODS We conducted a cross-sectional study among 1600 randomly selected adults aged 35 and older from four different socio-economical and ecological provinces. Information on socio-demographics, risk factors and health conditions was obtained from personal interviews. Clinical assessments including anthropometry (height, weight, waist and hip circumference) and blood pressure measurements were also conducted. Diabetes was classified based on self-reported diagnoses and a point-of-care glycated haemoglobin (HbA1c) test from finger prick blood samples. Stool samples for helminth diagnosis were examined with formalin-ether concentration technique for intestinal parasitic infections. The independent associations of helminth infections with diabetic status and HbA1c were assessed using multiple regression analyses. RESULTS The prevalence of pre-diabetes and diabetes was 37.3% and 22.8%, respectively. Fifty-six percent of diabetic cases were undiagnosed and 85% of diagnosed diabetic cases had poor glycemic control. Participants from rural areas and from southern parts of the country had higher infection rates, with Opisthorchis viverrini, being the most common helminth infection (30.5%). We found a positive association between Taenia spp. infections and HbA1c (β = 0.117; 95% CI: 0.042-0.200) and diabetes mellitus risk (OR = 2.98; 95% CI: 1.10-8.05). No other helminth species was associated with glycated hemoglobin. CONCLUSIONS Hyperglycaemia and diabetic rates in Lao PDR are alarmingly high, but consistent with other high rates in the region. Given the high rates of under-diagnosis and poorly-controlled glycaemia in diabetes mellitus patients, routine diabetes screening and treatment is essential for the local healthcare system. Large longitudinal cohorts integrating biomarkers are warranted in the search of causal diabetes mellitus risk factors in the region. Common intestinal helminth infections, including O. viverrini, are unlikely to explain the high diabetes mellitus rates observed.
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Affiliation(s)
- Nan Shwe Nwe Htun
- 0000 0004 0587 0574grid.416786.aDepartment of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, 4051 Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Peter Odermatt
- 0000 0004 0587 0574grid.416786.aDepartment of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, 4051 Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Phimpha Paboriboune
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Somphou Sayasone
- 0000 0004 0587 0574grid.416786.aDepartment of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, 4051 Basel, Switzerland
- grid.415768.9Lao Tropical and Public Health Institute, Ministry of Health, Vientiane, Lao People’s Democratic Republic
| | - Malisa Vongsakid
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Vilayouth Phimolsarn-Nusith
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Xuan Duong Tran
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Phoum-Savath Ounnavong
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Navalone Andriama-Hefasoa
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Nilun-Done Senvanpan
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Anousine Homsana
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Baocher Lianosay
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Dalouny Xayavong
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | | | - Phaivanh Bounsavath
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Phoy-Phaylinh Prasayasith
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Seng-Davanh Syphan
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Yi-Xiao Lu
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Kanchana Thilakoun
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Xaipa-Song Xaiyaphet
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Phout-Tasin Vongngakesone
- The Francophone Institute for Tropical Medicine (International Program for Health in the Tropics), Vientiane, Lao PDR
| | - Ikenna C Eze
- 0000 0004 0587 0574grid.416786.aDepartment of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, 4051 Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Medea Imboden
- 0000 0004 0587 0574grid.416786.aDepartment of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, 4051 Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Banchob Sripa
- 0000 0004 0470 0856grid.9786.0Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Daniel Reinharz
- 0000 0004 1936 8390grid.23856.3aUniversité Laval, Quebec City, Canada
| | - Nicole Probst-Hensch
- 0000 0004 0587 0574grid.416786.aDepartment of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, 4051 Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
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Ayana M, Vlaminck J, Cools P, Ame S, Albonico M, Dana D, Keiser J, Manly H, Matoso LF, Mekonnen Z, Montresor A, Correa-Oliveira R, Rinaldi L, Sayasone S, Sowersby S, Tesfaye L, Vercruysse J, Mirams G, Levecke B. Modification and optimization of the FECPAKG2 protocol for the detection and quantification of soil-transmitted helminth eggs in human stool. PLoS Negl Trop Dis 2018; 12:e0006655. [PMID: 30321180 PMCID: PMC6224113 DOI: 10.1371/journal.pntd.0006655] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/08/2018] [Accepted: 06/29/2018] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Standard diagnosis of human soil-transmitted helminth (STH) infections is based on the microscopic detection of helminth eggs in stool and supports programmatic decision making in control programs. However, the current standard diagnostic techniques still show a number of limitations. Recently, the FECPAKG2 method was developed to detect helminth infections and asses drug efficacy in sheep or cattle. It includes a device that takes digital images of helminth eggs that have been concentrated into one microscopic field of view and stores these images online for future evaluation. The goal of this study was to introduce a standard operating procedure (SOP) for the detection and quantification of human STH eggs using the FECPAKG2 and to optimize 2 crucial steps of the protocol, namely the sedimentation step (aimed at separating sinking eggs from floating debris) and the accumulation step (aimed at concentrating the eggs by flotation). METHODOLOGY/PRINCIPAL FINDINGS A total of 55 stool samples from naturally infected children were used from 4 different geographical areas (Ethiopia, Laos, Tanzania and Brazil). The results showed that Trichuris eggs generally moved slower than eggs of the other two STH species during both sedimentation in water in the FECPAKG2 sedimenter as during accumulation in flotation solution in the FECPAKG2 cassettes. The highest number of eggs were present in the slurry of the sedimenter after overnight sedimentation (Ascaris: 95.7%, Trichuris: 89.8% and hookworm: 94.2% of the eggs). A minimum of 24 minutes were needed to ensure the accumulation of at least 80% of the eggs from all three STH species in the FECPAKG2 cassette (Ascaris: 96.1%; Trichuris: 88.2% and hookworm: 87.6%). CONCLUSIONS/SIGNIFICANCE This study introduces for the first time a SOP for the FECPAKG2 method. Different aspects of the method for diagnosing human STH infections were optimized. Our study forms the basis for a thorough and objective evaluation of the system as a diagnostic tool that could be implemented in STH control programs.
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Affiliation(s)
- Mio Ayana
- Institute of Health, Faculty of Health Science, School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | - Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Piet Cools
- Institute of Health, Faculty of Health Science, School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | - Shaali Ame
- Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | - Marco Albonico
- Center for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Negrar, Italy
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Daniel Dana
- Institute of Health, Faculty of Health Science, School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Leonardo F. Matoso
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
- Nursing school, Federal university of Minas Gerais, Belo Horizonte, Brazil
| | - Zeleke Mekonnen
- Institute of Health, Faculty of Health Science, School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | | | - Rodrigo Correa-Oliveira
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Somphou Sayasone
- National Institute of Public Health, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Stephen Sowersby
- Department of Biochemistry, University of Otago, Otago, New Zealand
| | - Lensa Tesfaye
- Institute of Health, Faculty of Health Science, School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | | | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
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Leta GT, French M, Dorny P, Vercruysse J, Levecke B. Comparison of individual and pooled diagnostic examination strategies during the national mapping of soil-transmitted helminths and Schistosoma mansoni in Ethiopia. PLoS Negl Trop Dis 2018; 12:e0006723. [PMID: 30199526 PMCID: PMC6147605 DOI: 10.1371/journal.pntd.0006723] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 09/20/2018] [Accepted: 07/28/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Laboratory-based studies have highlighted that pooling stool and urine samples can reduce costs and diagnostic burden without a negative impact on the ability to estimate the intensity of soil-transmitted helminth (STH, Ascaris lumbricoides, Trichuris trichiura and hookworms) and schistosome infections (Schistosoma mansoni and S. haematobium). In this study, we compare individual and pooled stool examination strategies in a programmatic setting. METHODS Stool samples were collected from 2,650 children in 53 primary schools in Amhara Regional State, Ethiopia, during the national mapping of STHs and schistosome infections. Eggs of STHs and S. mansoni were quantified in both individual and pooled samples (pools were made from 10 individual samples) using a single Kato-Katz smear. PRINCIPAL FINDINGS A pooled diagnostic examination strategy provided comparable estimates of infection intensity with higher fecal egg count (expressed in eggs per gram of stool (EPG)) than those based on individual strategy (Ascaris: 45.1 EPG vs. 93.9, p = 0.03; Trichuris: 1.8 EPG vs. 2.1 EPG, p = 0.95; hookworms: 17.5 EPG vs. 28.5 EPG, p = 0.18; S. mansoni: 1.6 EPG vs. 3.4 EPG, p = 0.02), but had lower sensitivity (Ascaris: 90.0% vs. 55.0%; Trichuris: 91.7% vs. 16.7%; hookworms: 92.6% vs. 61.8%; S. mansoni: 100% vs. 51.7%, p < 0.001). A pooled approach resulted in a ~70% reduction in time required for sample testing, but reduced total operational costs by only ~11%. CONCLUSIONS/SIGNIFICANCE A pooled approach holds promise for the rapid assessment of intensity of helminth infections in a programmatic setting, but it is not major cost-saving strategy. Further investigation is required to determine when and how pooling can be utilized. Such work should also include validation of statistical methods to estimate prevalence based on pooling samples. Finally, the comparison of operational costs across different scenarios of national program management will help determine whether pooling is indeed worthwhile considering.
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Affiliation(s)
- Gemechu Tadesse Leta
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- * E-mail:
| | - Mike French
- RTI International, Washington D.C., United States of America
| | - Pierre Dorny
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Ojurongbe O, Okorie PN, Opatokun RL, Ojurongbe TA, Mabayoje VO, Olowe OA, Adeyeba OA. Prevalence and associated factors of Plasmodium falciparum and soil transmitted helminth infections among pregnant women in Osun state, Nigeria. Afr Health Sci 2018; 18:542-551. [PMID: 30602986 PMCID: PMC6307031 DOI: 10.4314/ahs.v18i3.11] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Plasmodium falciparum and soil transmitted helminth (STHs) infection are widespread in sub-Sahara Africa, where co-infection is also common. This study assessed the prevalence of these infections and their risk factors among pregnant women in Osogbo, Nigeria. METHODS A total of 200 pregnant women attending the antenatal clinic were recruited. Plasmodium falciparum was detected using thick and thin film methods, while formol ether concentration method was used for STHs detection. A questionnaire was used to investigate the possible risk factors associated with acquisition of malaria and helminth infections. RESULTS The prevalence of P. falciparum, STHs and their co-infection was 29.5%, 12% and 5% respectively. P. falciparum, STHs and P. falciparum + STHs co-infection was significantly higher in primigravidae (52.5% vs 58.3% vs 80%) than in secongravidae (18.6% vs 25.0% vs 20%) and multigravidae (28.8% vs 16.7% vs 0%) (p=0.02). Prevalence associated factors identified for P. falciparum was age (p=0.0001) while gravidity (p=0.02) was identified for P. falciparum + STHs co-infection. CONCLUSION High prevalence of P. falciparum and helminth infections was observed among the pregnant women with primigravidae being the most susceptible to co-infection. There is an urgent need to implement an effective malaria and STHs preventive method for this high risk population.
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Affiliation(s)
| | - Patricia Nkem Okorie
- Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan
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Conan PL, Flateau C, Delattre C, Cremades A, Andriamanantena D, Rapp C, Ficko C. Hypereosinophilia and epigastralgia after visiting Tunisia: a rare differential diagnosis of helminthiases. Med Sante Trop 2018; 28:334-336. [PMID: 30270843 DOI: 10.1684/mst.2018.0806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Causes of hypereosinophilia among travelers returning from North Africa are dominated by helminth infections, especially when associated with gastrointestinal signs. Non-infectious causes must nonetheless be investigated after negative microbiological assessment and failure of a broad empiric antiparasite treatment. We report the case of a young man with epigastralgia and major weight loss since a stay in Tunisia. Empiric treatment with albendazole was not successful. Eosinophilic gastroenteritis was diagnosed and resolved under corticosteroid treatment.
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Affiliation(s)
- P L Conan
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
| | - C Flateau
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
| | - C Delattre
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
| | - A Cremades
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
| | - D Andriamanantena
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
| | - C Rapp
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
| | - C Ficko
- Service de maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, 94160 Saint Mandé, France
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Moser W, Bärenbold O, Mirams GJ, Cools P, Vlaminck J, Ali SM, Ame SM, Hattendorf J, Vounatsou P, Levecke B, Keiser J. Diagnostic comparison between FECPAKG2 and the Kato-Katz method for analyzing soil-transmitted helminth eggs in stool. PLoS Negl Trop Dis 2018; 12:e0006562. [PMID: 29864132 PMCID: PMC6002127 DOI: 10.1371/journal.pntd.0006562] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 06/14/2018] [Accepted: 05/25/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Over one billion people are infected with soil-transmitted helminths (STH), i.e. Ascaris lumbricoides, hookworm and Trichuris trichiura. For estimating drug efficacy and monitoring anthelminthic drug resistance, accurate diagnostic methods are critical. FECPAKG2 is a new remote-diagnostic tool used in veterinary medicine, which produces an image of the stool sample that can be stored on an internet cloud. We compared for the first time FECPAKG2 with the recommended Kato-Katz method. METHODOLOGY/PRINCIPAL FINDINGS Two stool samples were collected from adolescent participants (age 15-18 years) at baseline and 14 to 21 days after treatment in the framework of a randomized clinical trial on Pemba Island, Tanzania. Stool samples were analyzed with different diagnostic efforts: i) one or ii) two Kato-Katz thick smears from the first sample, iii) two Kato-Katz thick smears from two samples and iv) FECPAKG2 from the first sample. Parameters were calculated based on a hierarchical Bayesian egg count model. Complete data for all diagnostic efforts were available from 615 participants at baseline and 231 hookworm-positive participants at follow-up. At baseline FECPAKG2 revealed a sensitivity of 75.6% (72.0-77.7) for detecting A. lumbricoides, 71.5% (67.4-95.3) for hookworm and 65.8% (64.9-66.2) for T. trichiura, which was significantly lower (all p<0.05) than any of the Kato-Katz methods and highly dependent on infection intensity. Despite that the egg counts based on FECPAKG2 were relatively lower compared to Kato-Katz by a ratio of 0.38 (0.32-0.43) for A. lumbricoides, 0.36 (0.33-0.40) for hookworm and 0.08 (0.07-0.09) for T. trichiura, the egg reduction rates (ERR) were correctly estimated with FECPAKG2. CONCLUSIONS/SIGNIFICANCE The sensitivity to identify any STH infection was considerably lower for FECPAKG2 compared to Kato-Katz. Following rigorous development, FECPAKG2 might be an interesting tool with unique features for epidemiological and clinical studies.
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Affiliation(s)
- Wendelin Moser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel Switzerland
- University of Basel, Basel, Switzerland
| | - Oliver Bärenbold
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Piet Cools
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Said M. Ali
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | - Shaali M. Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | - Jan Hattendorf
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Penelope Vounatsou
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel Switzerland
- University of Basel, Basel, Switzerland
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Abstract
Although examination of the stool for ova and parasites times three (O&P ×3) is routinely performed in the United States (US) for the evaluation of persistent and/or chronic diarrhea, the result is almost always negative. This has contributed to the perception that parasitic diseases are nearly non-existent in the country unless there is a history of travel to an endemic area. The increasing number of immigrants from third-world countries, tourists, and students who present with symptoms of parasitic diseases are often misdiagnosed as having irritable bowel syndrome or inflammatory bowel disease. The consequences of such misdiagnosis need no explanation. However, certain parasitic diseases are endemic to the US and other developed nations and affect both immunocompetent and immunocompromised patients. Testing for parasitic diseases either with O&P or with other diagnostic tests, followed by the recommended treatment, is quite rewarding when appropriate. Most parasitic diseases are easily treatable and should not be confused with other chronic gastrointestinal (GI) disorders. In this review, we critically evaluate the symptomatology of luminal parasitic diseases, their differential diagnoses, appropriate diagnostic tests, and management.
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Affiliation(s)
- Sonmoon Mohapatra
- Department of Internal Medicine, Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA. Department of Infectious Diseases, Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA. 3Department of Gastroenterology, Hepatology and Clinical Nutrition Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA
| | - Dhruv Pratap Singh
- Department of Internal Medicine, Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA. Department of Infectious Diseases, Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA. 3Department of Gastroenterology, Hepatology and Clinical Nutrition Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA
| | - David Alcid
- Department of Internal Medicine, Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA. Department of Infectious Diseases, Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA. 3Department of Gastroenterology, Hepatology and Clinical Nutrition Saint Peter's University Hospital - Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA
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Lim MD, Brooker SJ, Belizario VY, Gay-Andrieu F, Gilleard J, Levecke B, van Lieshout L, Medley GF, Mekonnen Z, Mirams G, Njenga SM, Odiere MR, Rudge JW, Stuyver L, Vercruysse J, Vlaminck J, Walson JL. Diagnostic tools for soil-transmitted helminths control and elimination programs: A pathway for diagnostic product development. PLoS Negl Trop Dis 2018; 12:e0006213. [PMID: 29494581 PMCID: PMC5832200 DOI: 10.1371/journal.pntd.0006213] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Mark D. Lim
- Global Health Division, The Bill & Melinda Gates Foundation, Seattle, United States of America
- * E-mail:
| | - Simon J. Brooker
- Global Health Division, The Bill & Melinda Gates Foundation, Seattle, United States of America
| | | | | | - John Gilleard
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Bruno Levecke
- Faculty of Veterinary Medicine, Gent University, Merelbeke, Belgium
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Graham F. Medley
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | | | | | - Maurice R. Odiere
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - James W. Rudge
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Jozef Vercruysse
- Faculty of Veterinary Medicine, Gent University, Merelbeke, Belgium
| | - Johnny Vlaminck
- Faculty of Veterinary Medicine, Gent University, Merelbeke, Belgium
| | - Judd L. Walson
- Departments of Global Health, Medicine (Infectious Disease), Pediatrics and Epidemiology, University of Washington, United States of America
- Natural History Museum, London, United Kingdom
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Cunningham LJ, Odoom J, Pratt D, Boatemaa L, Asante-Ntim N, Attiku K, Banahene B, Osei-Atweneboana M, Verweij JJ, Molyneux D, Stothard RJ, Adams ER. Expanding molecular diagnostics of helminthiasis: Piloting use of the GPLN platform for surveillance of soil transmitted helminthiasis and schistosomiasis in Ghana. PLoS Negl Trop Dis 2018; 12:e0006129. [PMID: 29370166 PMCID: PMC5784883 DOI: 10.1371/journal.pntd.0006129] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/22/2017] [Indexed: 01/13/2023] Open
Abstract
The efforts to control and eradicate polio as a global health burden have been successful to the point where currently only three countries now report endemic polio, and the number of cases of polio continues to decrease. The success of the polio programme has been dependant on a well-developed network of laboratories termed the global polio laboratory network (GPLN). Here we explore collaborative opportunities with the GPLN to target two of the 18 diseases listed as a neglected tropical diseases (NTD) namely soil transmitted helminthiasis (STH) and Schistosomiasis (SCH). These were chosen based on prevalence and the use of faecal materials to identify both polio, STH and SCH. Our study screened 448 faecal samples from the Ghana GPLN using three triplex TaqMan assays to identify Ascaris lumbricoides, Necator americanus, Ancylostoma spp, Trichuris trchiura, Strongyloides stercoralis and Schistosoma spp. Our results found a combined helminth prevalence of 22%. The most common helminth infection was A. lumbricoides with a prevalence of 15% followed by N. americanus (5%), Ancylostoma spp. (2.5%), Schistosoma spp. (1.6%) and S. stercoralis (1%). These results show that it is possible to identify alternative pathogens to polio in the samples collected by the GPLN platform and to introduce new diagnostic assays to their laboratories. The diagnostic methods employed were also able to identify S. stercoralis positive samples, which are difficult to identify using parasitological methods such as Kato-Katz. This study raises the possibility of collaboration with the GPLN for the surveillance of a wider range of diseases which would both benefit the efforts to control the NTDs and also increase the scope of the GPLN as a diagnostic platform. The successful campaign being waged against polio has eliminated the disease from most countries where it was once endemic. With this success, it is anticipated that the disease will be eradicated in the coming years with only 37 cases being reported in 2016. Although the efforts to control polio are successful there are a number of low-profile, but no less serious disease, that are still highly prevalent throughout the world. These diseases have been termed the neglected tropical diseases (NTD) and this study aims to test the suitability of the Global Polio Laboratory Network (GPLN) as a platform to screen for two of the NTDs, soil transmitted helminthiasis (STH) and schistosomiasis (SCH). To test the suitability of the samples collected by the GPLN and the suitability of the laboratories themselves 448 samples from the Ghanaian GPLN laboratory were screened with multiplex TaqMan assays for the following six helminth types: Ascaris lumbricoides, Necator americanus, Ancylostoma spp, Trichuris trchiura, Strongyloides stercoralis and Schistosoma spp. Using this method this study was able to identify a prevalence of 22% for the combined helminth infection. The most common infection was A. lumbricoides with a prevalence of 15% followed by N. americanus (5%), Ancylostoma spp. (2.5%), Schistosoma spp. (1.6%) and S. stercoralis (1%). The success of this study indicates that this may be a cost-effective method to passively screen a country for STH and SCH and its success in identifying S. stercoralis infections makes it especially useful as this parasite is hard to identify using traditional surveillance techniques.
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Affiliation(s)
- Lucas J. Cunningham
- Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | - John Odoom
- Virology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Deborah Pratt
- Virology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Linda Boatemaa
- Virology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Nana Asante-Ntim
- Virology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Keren Attiku
- Virology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Bismarck Banahene
- Virology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Mike Osei-Atweneboana
- Department of Environmental Biology and Health, Council for Scientific and Industrial Research, Accra, Ghana
| | - Jaco J. Verweij
- Laboratory for Medical Microbiology and Immunology, St Elisabeth Hospital, Tilburg, the Netherlands
| | - David Molyneux
- Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Russell J. Stothard
- Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Emily R. Adams
- Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Abstract
More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consider the possibility of infection in individuals living in, or returning from, endemic regions. Although safe and effective drugs are donated free to endemic countries, only half of at-risk children received treatment in 2016. This Seminar describes the epidemiology, lifecycles, pathophysiology, clinical diagnosis, management, and public health control of soil-transmitted helminths. Previous work has questioned the effect of population-level deworming; however, it remains beyond doubt that treatment reduces the severe consequences of soil-transmitted helminthiasis. We highlight the need for refined diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and management of these infections.
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Affiliation(s)
- Peter Mark Jourdan
- Schistosomiasis Control Initiative, Imperial College London, St Mary's Campus, London, UK; DEWORM3, Natural History Museum, London, UK; Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Poppy H L Lamberton
- Department of Infectious Disease Epidemiology, Imperial College London, St Mary's Campus, London, UK; Institute of Biodiversity, Animal Health and Comparative Medicine, The University of Glasgow, Glasgow, UK; Wellcome Centre for Molecular Parasitology, The University of Glasgow, Glasgow, UK.
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College London, St Mary's Campus, London, UK
| | - David G Addiss
- The Task Force for Global Health, Decatur, GA, USA; Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
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Werkman M, Wright JE, Truscott JE, Easton AV, Oliveira RG, Toor J, Ower A, Ásbjörnsdóttir KH, Means AR, Farrell SH, Walson JL, Anderson RM. Testing for soil-transmitted helminth transmission elimination: Analysing the impact of the sensitivity of different diagnostic tools. PLoS Negl Trop Dis 2018; 12:e0006114. [PMID: 29346366 PMCID: PMC5773090 DOI: 10.1371/journal.pntd.0006114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 11/14/2017] [Indexed: 12/27/2022] Open
Abstract
In recent years, an increased focus has been placed upon the possibility of the elimination of soil-transmitted helminth (STH) transmission using various interventions including mass drug administration. The primary diagnostic tool recommended by the WHO is the detection of STH eggs in stool using the Kato-Katz (KK) method. However, detecting infected individuals using this method becomes increasingly difficult as the intensity of infection decreases. Newer techniques, such as qPCR, have been shown to have greater sensitivity than KK, especially at low prevalence. However, the impact of using qPCR on elimination thresholds is yet to be investigated. In this paper, we aim to quantify how the sensitivity of these two diagnostic tools affects the optimal prevalence threshold at which to declare the interruption of transmission with a defined level of confidence. A stochastic, individual-based STH transmission model was used in this study to simulate the transmission dynamics of Ascaris and hookworm. Data from a Kenyan deworming study were used to parameterize the diagnostic model which was based on egg detection probabilities. The positive and negative predictive values (PPV and NPV) were calculated to assess the quality of any given threshold, with the optimal threshold value taken to be that at which both were maximised. The threshold prevalence of infection values for declaring elimination of Ascaris transmission were 6% and 12% for KK and qPCR respectively. For hookworm, these threshold values are lower at 0.5% and 2% respectively. Diagnostic tests with greater sensitivity are becoming increasingly important as we approach the elimination of STH transmission in some regions of the world. For declaring the elimination of transmission, using qPCR to diagnose STH infection results in the definition of a higher prevalence, than when KK is used. Soil-transmitted helminths are categorised as a neglected tropical disease and comprise four dominant species (two hookworms, Trichuris trichuria & Ascaris lumbricoides) that affect the poorest people in the world. The World Health Organisation (WHO) has made great strides in reducing the morbidity induced by STH infections in pre-school aged and school-aged children through mass drug administration. Many countries are now considering moving from morbidity reduction in school-aged children to community-wide treatment with the aim of transmission elimination. These helminths reproduce sexually within a human host and therefore both male and female worms must be present to produce fertilized eggs. The density of female and male worms below which mating success is too low to sustain parasite populations is defined as the ‘breakpoint’ in transmission. Both the prevalence and intensity of infection are very low as this breakpoint is approached when worm numbers are highly aggregated in their distribution within the human host population. Consequently, it becomes increasingly challenging to identify infected individuals using standard microscopic diagnostic tools (such as Kato-Katz). New and more sensitive molecular diagnostics tools, such as qPCR, are a necessity in settings where communities are moving towards the interruption of transmission. This paper demonstrates that the threshold to declare interruption of transmission is 50% lower when microscopic techniques are applied compared with molecular techniques.
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Affiliation(s)
- Marleen Werkman
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
- * E-mail:
| | - James E. Wright
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - James E. Truscott
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - Alice V. Easton
- Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda MD, United States of America
| | - Rita G. Oliveira
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
| | - Jaspreet Toor
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
| | - Alison Ower
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
| | - Kristjana H. Ásbjörnsdóttir
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Arianna R. Means
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Sam H. Farrell
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
| | - Judd L. Walson
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Roy M. Anderson
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
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Tang MS, Bowcutt R, Loke P. Assessing the Mouse Intestinal Microbiota in Settings of Type-2 Immune Responses. Methods Mol Biol 2018; 1799:359-370. [PMID: 29956164 DOI: 10.1007/978-1-4939-7896-0_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The microbial communities that reside within the mammalian host play important roles in the development of a robust host immune system. With the advent of sequencing technology and barcoding strategy of the bacterial 16S ribosomal RNA (rRNA) gene, microbiota studies are becoming more economical but also more important in many immunology studies. Here, we described a representative study protocol to characterize how the microbiota changes during an intestinal helminth infection, with emphasis on subtle aspects of the experimental design that are critical for data interpretation.
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Affiliation(s)
- Mei San Tang
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Rowann Bowcutt
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
- UCB Celltech, Slough, UK
| | - P'ng Loke
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.
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Hagge DA, Parajuli P, Kunwar CB, Rana DRSJB, Thapa R, Neupane KD, Nicholls P, Adams LB, Geluk A, Shah M, Napit IB. Opening a Can of Worms: Leprosy Reactions and Complicit Soil-Transmitted Helminths. EBioMedicine 2017; 23:119-124. [PMID: 28882756 PMCID: PMC5605364 DOI: 10.1016/j.ebiom.2017.08.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 12/11/2022] Open
Abstract
Background > 94% of new annual leprosy cases are diagnosed in populations co-endemic for soil-transmitted helminths (STH). STH can profoundly dysregulate host immune responses towards Th2 bias, which can be restored over time after deworming. We hypothesize that STH co-infection is associated with leprosy reaction (denoted as simply “reaction” herein) occurrence within a co-endemic population. Methods A cohort study was performed on a cohort of Nepalese leprosy patients across treatment and diagnostic classifications who were screened by routine fecal smear microscopy and multiplex quantitative PCR (qPCR) for Ascaris lumbricoides (Al), Strongyloides stercoralis (Ss), Ancyclostoma duodenale (Ad) and Necator americanus (Na). Results Among 145 patients, 55% were positive for ≥ 1 STH (STH +): 34% Al +, 18% Ss +, 17% Ad + and 5% Na +. Significant inverse STH and reaction relationships were evidenced by the bulk of cases: 63% reaction-negative were STH + of total cases (p = 0.030) while 65% reaction-positive were STH − in new cases (96; p = 0.023). Strikingly, the majority of STH + were reaction-negative, even when considering each species: 59% Al +, 60% Ss +, 62% Ad + and 67% Na + of new leprosy cases. Conclusions Absence of STH co-infection is associated with leprosy reaction at diagnosis within a co-endemic population. This is likely due to immune reconstitution effects after deworming or interruption of chronic STH-mediated immune dysregulation. Fecal screening by qPCR revealed that 55% of 145 leprosy patients hosted 1 or more soil-transmitted helminth (STH) co-infections STH coinfection was significantly and inversely associated with leprosy reaction Chronic STH-induced immune bias followed by disruption of co-infection, potentially by deworming, may initiate immune reconstitution that can lead to reaction development
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Affiliation(s)
- Deanna A Hagge
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal.
| | - Pawan Parajuli
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
| | - Chhatra B Kunwar
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
| | - Divya R S J B Rana
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
| | - Ruby Thapa
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
| | - Kapil D Neupane
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
| | - Peter Nicholls
- School of Health Sciences, University of Southampton, Southampton, United Kingdom
| | - Linda B Adams
- Department of Health and Human Services, Health Resources and Services Administration, Health Systems Bureau, National Hansen's Disease Programs (DHHS/HRSA/HSB/NHDP), Baton Rouge, Louisiana, USA
| | - Annemieke Geluk
- Department of Infectious Diseases, Leiden University Medical Center, The Netherlands
| | - Mahesh Shah
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
| | - Indra B Napit
- Mycobacterial Research Laboratories, Anandaban Hospital, Kathmandu, Nepal
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Turner HC, Bettis AA, Dunn JC, Whitton JM, Hollingsworth TD, Fleming FM, Anderson RM. Economic Considerations for Moving beyond the Kato-Katz Technique for Diagnosing Intestinal Parasites As We Move Towards Elimination. Trends Parasitol 2017; 33:435-443. [PMID: 28187989 PMCID: PMC5446322 DOI: 10.1016/j.pt.2017.01.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/29/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022]
Abstract
While the need for more sensitive diagnostics for intestinal helminths is well known, the cost of developing and implementing new tests is considered relatively high compared to the Kato-Katz technique. Here, we review the reported costs of performing the Kato-Katz technique. We also outline several economic arguments we believe highlight the need for further investment in alternative diagnostics, and considerations that should be made when comparing their costs. In our opinion, we highlight that, without new diagnostic methods, it will be difficult for policy makers to make the most cost-effective decisions and that the potentially higher unit costs of new methods can be outweighed by the long-term programmatic benefits they have (such as the ability to detect the interruption of transmission).
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Affiliation(s)
- Hugo C Turner
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK; Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Alison A Bettis
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK
| | - Julia C Dunn
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK
| | - Jane M Whitton
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, Norfolk Place, London W2 1PG, UK
| | - T Déirdre Hollingsworth
- Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK; School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Fiona M Fleming
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK
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Kabore A, Ibikounle M, Tougoue JJ, Mupoyi S, Ndombe M, Shannon S, Ottesen EA, Mukunda F, Awaca N. Initiating NTD programs targeting schistosomiasis and soil-transmitted helminthiasis in two provinces of the Democratic Republic of the Congo: Establishment of baseline prevalence for mass drug administration. Acta Trop 2017; 166:177-185. [PMID: 27888125 DOI: 10.1016/j.actatropica.2016.11.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/05/2016] [Accepted: 11/16/2016] [Indexed: 01/06/2023]
Abstract
BACKGROUND Schistosomiasis (SCH) and soil-transmitted helminthiasis (STH) are widely distributed in the Democratic Republic of the Congo (DRC) and constitute a serious public health problem. As recommended by the World Health Organization (WHO), before launching mass chemotherapy to control these diseases, parasitological surveys were conducted in sentinel sites in six health zones (HZs) in Bandundu and Maniema provinces. Baseline prevalence and intensity of infection for SCH and STH were determined to establish the appropriate treatment plan using Praziquantel (PZQ) and Albendazole (ALB). METHODS Parasitological surveys were conducted from April to May 2015 in twenty-six selected sampling units (schools) for baseline mapping in six HZs: Fifty school children (25 females and 25 males) aged 9-15 years were randomly selected per sampling unit. A total of 1300 samples (urine and stool) were examined using haematuria dipsticks, parasite-egg filtration and the point-of-care Circulating Cathodic Antigen (POC-CCA) assay for urine samples and the Kato-Katz technique for stool specimens. RESULTS Three species of schistosomes (S. mansoni, S. haematobium and S. intercalatum) and three groups of STH (hookworm, Ascaris and Trichuris) were detected at variable prevalence and intensity among the schools, the HZs and the provinces. In Bandundu, no SCH was detected by either Kato-Katz or the POC-CCA technique, despite a high prevalence of STH with 68% and 80% at Kiri and Pendjua HZs, respectively. In Maniema, intestinal schistosomiasis was detected by both Kato-Katz and POC-CCA with an average prevalence by Kato-Katz of 32.8% and by POC-CCA of 42.1%. Comparative studies confirmed the greater sensitivity (and operational feasibility) of the POC-CCA test on urine compared to Kato-Katz examination of stool for diagnosing intestinal schistosomiasis even in areas of comparatively light infections. STH was widely distributed and present in all HZs with a mean prevalence (95% CI) of 59.62% (46.00-65.00%). The prevalence of hookworm, roundworm and whipworm were 51.62% (32.40%-71.50%), 15.77% (0.50%-39.60%) and 13.46 (0.50%-33.20%), respectively. CONCLUSION This study provided the evidence base for implementing programs targeting SCH and STH in these Health Zones. Observations also reinforce the operational value and feasibility of the POC-CCA test to detect S. mansoni and, for the first time, S. intercalatum infections in a routine NTD program setting.
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Affiliation(s)
- Achille Kabore
- RTI International, District of Columbia, 3040 Cornwallis Road, Research Triangle Park, NC 27709, WA, United States.
| | - Moudachirou Ibikounle
- Département de Zoologie, Faculté des Sciences et Techniques, Université d'Abomey-Calavi 01BP526, Cotonou, Benin.
| | - Jean Jacques Tougoue
- RTI International, District of Columbia, 3040 Cornwallis Road, Research Triangle Park, NC 27709, WA, United States.
| | - Sylvain Mupoyi
- Coordination nationale des maladies tropicales négligées, programme national de lutte contre la bilharziose, Gombe, Kinshasa, Democratic Republic of the Congo.
| | - Martin Ndombe
- RTI International, ENVISION Program, DRC-Office, 4630, Avenue de la Science, Gombe Kinshasa, Democratic Republic of the Congo.
| | - Scott Shannon
- IMA World Health, DRC-Office, 14 Av Sergent Moke, Ngaliema Kinshasa, Democratic Republic of the Congo.
| | - Eric A Ottesen
- RTI International, District of Columbia, 3040 Cornwallis Road, Research Triangle Park, NC 27709, WA, United States.
| | - Faustin Mukunda
- Coordination nationale des maladies tropicales négligées, programme national de lutte contre la bilharziose, Gombe, Kinshasa, Democratic Republic of the Congo.
| | - Naomi Awaca
- Coordination nationale des maladies tropicales négligées, programme national de lutte contre l'onchocercose, Gombe, Kinshasa, Democratic Republic of the Congo.
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Hawkins KR, Cantera JL, Storey HL, Leader BT, de los Santos T. Diagnostic Tests to Support Late-Stage Control Programs for Schistosomiasis and Soil-Transmitted Helminthiases. PLoS Negl Trop Dis 2016; 10:e0004985. [PMID: 28005900 PMCID: PMC5179049 DOI: 10.1371/journal.pntd.0004985] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Global efforts to address schistosomiasis and soil-transmitted helminthiases (STH) include deworming programs for school-aged children that are made possible by large-scale drug donations. Decisions on these mass drug administration (MDA) programs currently rely on microscopic examination of clinical specimens to determine the presence of parasite eggs. However, microscopy-based methods are not sensitive to the low-intensity infections that characterize populations that have undergone MDA. Thus, there has been increasing recognition within the schistosomiasis and STH communities of the need for improved diagnostic tools to support late-stage control program decisions, such as when to stop or reduce MDA. Failure to adequately address the need for new diagnostics could jeopardize achievement of the 2020 London Declaration goals. In this report, we assess diagnostic needs and landscape potential solutions and determine appropriate strategies to improve diagnostic testing to support control and elimination programs. Based upon literature reviews and previous input from experts in the schistosomiasis and STH communities, we prioritized two diagnostic use cases for further exploration: to inform MDA-stopping decisions and post-MDA surveillance. To this end, PATH has refined target product profiles (TPPs) for schistosomiasis and STH diagnostics that are applicable to these use cases. We evaluated the limitations of current diagnostic methods with regards to these use cases and identified candidate biomarkers and diagnostics with potential application as new tools. Based on this analysis, there is a need to develop antigen-detecting rapid diagnostic tests (RDTs) with simplified, field-deployable sample preparation for schistosomiasis. Additionally, there is a need for diagnostic tests that are more sensitive than the current methods for STH, which may include either a field-deployable molecular test or a simple, low-cost, rapid antigen-detecting test.
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Affiliation(s)
- Kenneth R. Hawkins
- Diagnostics Program, PATH, Seattle, Washington, United States of America
- * E-mail:
| | - Jason L. Cantera
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Helen L. Storey
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Brandon T. Leader
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Tala de los Santos
- Diagnostics Program, PATH, Seattle, Washington, United States of America
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