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Papaiakovou M, Cimino RO, Pilotte N, Dunn J, Littlewood DTJ, Williams SA, Krolewiecki AJ, Mejia R. Comparison of multi-parallel quantitative real-time PCRs targeting different DNA regions and detecting soil-transmitted helminths in stool. Parasit Vectors 2024; 17:390. [PMID: 39272159 PMCID: PMC11397029 DOI: 10.1186/s13071-024-06464-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 08/21/2024] [Indexed: 09/15/2024] Open
Abstract
BACKGROUND Soil-transmitted helminths infect an estimated 18% of the world's population, causing a significant health burden. Microscopy has been the primary tool for diagnosing eggs from fecal samples, but its sensitivity drops in low-prevalence settings. Quantitative real-time polymerase chain reaction (qPCR) is slowly increasing in research and clinical settings. However, there is still no consensus on preferred qPCR targets. METHODS We aimed to compare soil-transmitted helminth (STH) DNA detection methods by testing naïve stool samples spiked with known quantities of STH eggs and larvae. DNA extracts from spiked samples were tested using independent quantitative realtime PCR (qPCR) assays targeting ribosomal or putative non-protein coding satellite sequences. RESULTS For Trichuris trichiura, there was a strong correlation between egg/larvae counts and qPCR results using either qPCR method (0.86 and 0.87, respectively). Strong correlations also existed for A. lumbricoides (0.60 and 0.63, respectively), but weaker correlations were found for Ancylostoma duodenale (0.41 for both assays) and Strongyloides stercoralis (0.48 and 0.65, respectively). No correlation for Necator americanus was observed when testing with either qPCR assay. Both assays had fair-to-moderate agreement across targets when using field-collected stool samples (0.28-0.45, for all STHs), except for S. stercoralis (0.12) with slight agreement. CONCLUSIONS There is a strong correlation between qPCR results and egg/larvae counts. Our study confirms that qPCR is an effective diagnostic tool, even with low-intensity infections, regardless of the DNA-based diagnostic marker used. However, the moderate agreement between the two different qPCR assays when testing field samples highlights the need to understand the role of these targets in the genome so that the parasite burden can be quantified more accurately and consistently by qPCR.
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Affiliation(s)
- Marina Papaiakovou
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA.
- Biodiversity & Health, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK.
| | - Rubén O Cimino
- Instituto de Investigación de Enfermedades Tropicales (IIET), Universidad Nacional de Salta. Sede Regional Orán, Salta, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA
- Department of Biology, Quinnipiac University, Hamden, CT, 06518, USA
| | - Julia Dunn
- Department of Infectious Disease and Epidemiology, Imperial College London, London, W2 1PG, UK
| | | | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA
| | - Alejandro J Krolewiecki
- Instituto de Investigación de Enfermedades Tropicales (IIET), Universidad Nacional de Salta. Sede Regional Orán, Salta, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Rojelio Mejia
- Instituto de Investigación de Enfermedades Tropicales (IIET), Universidad Nacional de Salta. Sede Regional Orán, Salta, Argentina.
- Section of Tropical Medicine, Department of Pediatrics, National School of Tropical Medicine, Texas Children's Hospital and Baylor College of Medicine, Houston, TX, 77030, USA.
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Yang R, Xu M, Zhang L, Liao Y, Liu Y, Deng X, Wang L. Human Strongyloides stercoralis infection. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2024:S1684-1182(24)00120-8. [PMID: 39142910 DOI: 10.1016/j.jmii.2024.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 06/14/2024] [Accepted: 07/15/2024] [Indexed: 08/16/2024]
Abstract
Strongyloides stercoralis is an important soil-transmitted helminth occurring world-wide and affecting 30-100 million people. Because many cases are asymptomatic and sensitive diagnostic methods are lacking, S. stercoralis infection is frequently underdiagnosed. The increasing incidence of autoimmune and wasting diseases and increased use of immunosuppressive agents, as well as the increased use of immunosuppressants and cytotoxic drugs, have increased S. stercoralis infection and their mortality. This review provides information about S. stercoralis epidemiology, life cycle, aetiology, pathology, comorbidities, immunology, vaccines, diagnosis, treatment, prevention, control and makes some recommendations for future prevention and control of this important parasite.
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Affiliation(s)
- Ruibing Yang
- Guangzhou Kingmed Center for Clinical Laboratory, Guangzhou, Guangdong 510320, China
| | - Meiyining Xu
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Lichao Zhang
- Guangdong Clinical Laboratory Center Guangdong Provincial People's Hospital, Guangzhou 510080, China
| | - Yao Liao
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, Guangdong 510180, China
| | - Yuheng Liu
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, Guangdong 510180, China
| | - Xiaoyan Deng
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, Guangdong 510180, China.
| | - Lifu Wang
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, Guangdong 510180, China.
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Salim Masoud N, Knopp S, Lenz N, Lweno O, Abdul Kibondo U, Mohamed A, Schindler T, Rothen J, Masimba J, S. Mohammed A, Althaus F, Abdulla S, Tanner M, Daubenberger C, Genton B. The impact of soil transmitted helminth on malaria clinical presentation and treatment outcome: A case control study among children in Bagamoyo district, coastal region of Tanzania. PLoS Negl Trop Dis 2024; 18:e0012412. [PMID: 39133750 PMCID: PMC11341094 DOI: 10.1371/journal.pntd.0012412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 08/22/2024] [Accepted: 07/29/2024] [Indexed: 08/24/2024] Open
Abstract
BACKGROUND Parasitic infectious agents rarely occur in isolation. Epidemiological evidence is mostly lacking, and little is known on how the two common parasites Plasmodium and soil transmitted helminths (STH) interact. There are contradictory findings in different studies. Synergism, antagonism and neutral effect have been documented between Plasmodium and STH. This study investigated the impact of STH on clinical malaria presentation and treatment outcome. METHODS A matched case control study with a semi longitudinal follow up according to World Health Organization (WHO) antimalarial surveillance guideline was done among children aged 2 months to 9 years inclusively living in western rural areas of Bagamoyo, coastal region of Tanzania. Cases were children with uncomplicated and severe malaria enrolled from the health facilities while controls were children with asymptomatic Plasmodium parasitemia enrolled from the same community. RESULTS In simple conditional regression analysis there was a tendency for a protective effect of STH on the development of clinical malaria [OR = 0.6, 95% CI of 0.3-1.3] which was more marked for Enterobius vermicularis species [OR = 0.2, 95% CI of 0.0-0.9]. On the contrary, hookworm species tended to be associated with increased risk of clinical malaria [OR = 3.0, 95% CI of 0.9-9.5]. In multiple conditional regression analysis, the overall protective effect was lower for all helminth infection [OR = 0.8, 95% CI of 0.3-1.9] but remained significantly protective for E. vermicularis species [OR = 0.1, 95% CI of 0.0-1.0] and borderline significant for hookworm species [OR = 3.6, 95% CI of 0.9-14.3]. Using ordinal logistic regression which better reflects the progression of asymptomatic Plasmodium parasitemia to severe malaria, there was a 50% significant protective effect with overall helminths [OR = 0.5, 95% CI of 0.3-0.9]. On the contrary, hookworm species was highly predictive of uncomplicated and severe malaria [OR = 7.8, 95% (CI of 1.8-33.9) and 49.7 (95% CI of 1.9-1298.9) respectively]. Generally, children infected with STH had higher geometric mean time to first clearance of parasitemia. CONCLUSION The findings of a protective effect of E. vermicularis and an enhancing effect of hookworms may explain the contradictory results found in the literature about impact of helminths on clinical malaria. More insight should be gained on possible mechanisms for these opposite effects. These results should not deter at this stage deworming programs but rather foster implementation of integrated control program for these two common parasites.
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Affiliation(s)
- Nahya Salim Masoud
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
- Department of Pediatrics and Child Health, Muhimbili University Health and Allied Sciences (MUHAS), Dar es Salaam, United Republic of Tanzania
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Stefanie Knopp
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nicole Lenz
- Food Microbial Systems, Risk Assessment and Mitigation Group, Agroscope, Bern, Switzerland
| | - Omar Lweno
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Ummi Abdul Kibondo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Ali Mohamed
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Tobias Schindler
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
- University of Basel, Basel, Switzerland
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Julian Rothen
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
- University of Basel, Basel, Switzerland
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - John Masimba
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Alisa S. Mohammed
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Fabrice Althaus
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Health Unit, International Committee of the Red Cross (ICRC), Geneva, Switzerland
| | - Salim Abdulla
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Marcel Tanner
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Claudia Daubenberger
- University of Basel, Basel, Switzerland
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Blaise Genton
- Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland
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Miller ML, Rota C, Welsh A. Transforming gastrointestinal helminth parasite identification in vertebrate hosts with metabarcoding: a systematic review. Parasit Vectors 2024; 17:311. [PMID: 39030625 PMCID: PMC11265005 DOI: 10.1186/s13071-024-06388-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 07/03/2024] [Indexed: 07/21/2024] Open
Abstract
BACKGROUND Gastrointestinal helminths are a very widespread group of intestinal parasites that can cause major health issues in their hosts, including severe illness or death. Traditional methods of helminth parasite identification using microscopy are time-consuming and poor in terms of taxonomic resolution, and require skilled observers. DNA metabarcoding has emerged as a powerful alternative for assessing community composition in a variety of sample types over the last few decades. While metabarcoding approaches have been reviewed for use in other research areas, the use of metabarcoding for parasites has only recently become widespread. As such, there is a need to synthesize parasite metabarcoding methodology and highlight the considerations to be taken into account when developing a protocol. METHODS We reviewed published literature that utilized DNA metabarcoding to identify gastrointestinal helminth parasites in vertebrate hosts. We extracted information from 62 peer-reviewed papers published between 2014 and 2023 and created a stepwise guide to the metabarcoding process. RESULTS We found that studies in our review varied in technique and methodology, such as the sample type utilized, genetic marker regions targeted and bioinformatic databases used. The main limitations of metabarcoding are that parasite abundance data may not be reliably attained from sequence read numbers, metabarcoding data may not be representative of the species present in the host and the cost and bioinformatic expertise required to utilize this method may be prohibitive to some groups. CONCLUSIONS Overall, using metabarcoding to assess gastrointestinal parasite communities is preferable to traditional methods, yielding higher taxonomic resolution, higher throughput and increased versatility due to its utility in any geographical location, with a variety of sample types, and with virtually any vertebrate host species. Additionally, metabarcoding has the potential for exciting new discoveries regarding host and parasite evolution.
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Affiliation(s)
- Madison L Miller
- Division of Forestry and Natural Resources, West Virginia University, Morgantown, WV, USA.
| | - Christopher Rota
- Division of Forestry and Natural Resources, West Virginia University, Morgantown, WV, USA
| | - Amy Welsh
- Division of Forestry and Natural Resources, West Virginia University, Morgantown, WV, USA
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Soultani M, Bartlett AW, Mendes EP, Hii SF, Traub R, Palmeirim MS, Lufunda LMM, Colella V, Lopes S, Vaz Nery S. Estimating Prevalence and Infection Intensity of Soil-Transmitted Helminths Using Quantitative Polymerase Chain Reaction and Kato-Katz in School-Age Children in Angola. Am J Trop Med Hyg 2024; 110:1145-1151. [PMID: 38688261 PMCID: PMC11154060 DOI: 10.4269/ajtmh.23-0821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/31/2024] [Indexed: 05/02/2024] Open
Abstract
Quantitative polymerase chain reaction (qPCR) is gaining recognition in soil-transmitted helminth (STH) diagnostics, especially for Strongyloides stercoralis and differentiating hookworm species. However, sample preservation and DNA extraction may influence qPCR performance. We estimated STH prevalence and infection intensity by using qPCR in schoolchildren from Huambo, Uige, and Zaire, Angola, and compared its performance with that of the Kato-Katz technique (here termed Kato-Katz). Stool samples from 3,063 children (219 schools) were preserved in 96% ethanol and analyzed by qPCR, of which 2,974 children (215 schools) had corresponding Kato-Katz results. Cluster-adjusted prevalence and infection intensity estimates were calculated by qPCR and Kato-Katz, with cycle threshold values converted to eggs per gram for qPCR. Cohen's kappa statistic evaluated agreement between qPCR and Kato-Katz. DNA extraction and qPCR were repeated on 191 (of 278) samples that were initially qPCR negative but Kato-Katz positive, of which 112 (58.6%) became positive. Similar prevalence for Ascaris lumbricoides (37.5% versus 34.6%) and Trichuris trichiura (6.5% versus 6.1%) were found by qPCR and Kato-Katz, respectively, while qPCR detected a higher hookworm prevalence (11.9% versus 2.9%). The prevalence of moderate- or high-intensity infections was higher by Kato-Katz than by qPCR. Agreement between qPCR and Kato-Katz was very good for A. lumbricoides, moderate for T. trichiura, and fair for hookworm. Strongyloides stercoralis prevalence was 4.7% (municipality range, 0-14.3%), and no Ancylostoma ceylanicum was detected by qPCR. Despite suboptimal performance, presumably due to fixative choice, qPCR was fundamental in detecting S. stercoralis and excluding zoonotic A. ceylanicum. Further evaluations on sample fixatives and DNA extraction methods are needed to optimize and standardize the performance of qPCR.
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Affiliation(s)
- Muzhgan Soultani
- School of Population Health, University of New South Wales, Sydney, Australia
| | - Adam W. Bartlett
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Elsa P. Mendes
- National Directorate of Public Health, Ministry of Health, Luanda, Angola
| | - Sze Fui Hii
- Faculty of Science, University of Melbourne, Parkville, Australia
| | - Rebecca Traub
- Faculty of Science, University of Melbourne, Parkville, Australia
| | - Marta S. Palmeirim
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Vito Colella
- Faculty of Science, University of Melbourne, Parkville, Australia
| | | | - Susana Vaz Nery
- Kirby Institute, University of New South Wales, Sydney, Australia
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Wisetmora A, Artchayasawat A, Boonmars T, Laummaunwai P, Pitaksakulrat O, Wattanawong O. Misclassification of Opisthorchis viverrini and Minute Intestinal Fluke Eggs by Routine Laboratory Staff Using Images from the Kato-Katz Method. Asian Pac J Cancer Prev 2024; 25:1473-1476. [PMID: 38809618 PMCID: PMC11318816 DOI: 10.31557/apjcp.2024.25.5.1473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 05/04/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND The Kato-Katz method is a commonly used diagnostic tool for helminth infections, particularly in field studies. This method can yield inaccurate results when samples contain eggs that are similar in appearance, such as Minute Intestinal Fluke (MIF) and Opisthorchis viverrini (OV) eggs. The close resemblance of eggs can be problematic and raises the possibility of false diagnoses. The objectives were to compare the diagnostic performance of the Kato-Katz method for accurately identifying MIF and OV and to provide evidence of possible misclassification. Methods: Based on questionnaire responses from 15 (young parasitologists and public health staff), the test comprised 50 MIF egg images and 50 OV egg images, for a total of 100 Google Form questionnaires. RESULTS The morphology of MIF and OV eggs found size and shape similarity and found that the shoulder rims were small, while the OV egg found the knobs had disappeared. The opercular conjunction was apparent, the shoulder rims and miricidium were prominent. The average percentage of correctly classified infections was 61.6 ± 12.1%. The accuracy percentages for both public health staff and young parasitologists in identifying were found to be 59.0 ± 14.8 and 66.8 ± 2.8, respectively. There was no significant difference observed in both groups. CONCLUSION These findings highlight the need for improving the accuracy of parasite identification. Preserving stool samples before the Kato-Katz method can help mitigate the potential degradation or distortion of parasite eggs. The incorrect classification of both eggs had an impact on treatment plans and the policy of parasite control programs.
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Affiliation(s)
- Ampas Wisetmora
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
- Division of General Communicable Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, 11000, Thailand.
| | - Atchara Artchayasawat
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
- Department of Agriculture and Resources, Faculty of Natural Resources and Agro-Industry, Kasetsart University, Chalermphrakiat Sakon Nakhon Province Campus, Muang Distric, Sakon Nakhon Province, 47000, Thailand.
| | - Thidarut Boonmars
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
| | - Porntip Laummaunwai
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
| | - Opal Pitaksakulrat
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
| | - Oranard Wattanawong
- Office of Diseases Prevention and Control 4 Saraburi, Ministry of Public Health, Saraburi, 18120, Thailand.
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Oyeyemi OT, Ogundahunsi O, Schunk M, Fatem RG, Shollenberger LM. Neglected tropical disease (NTD) diagnostics: current development and operations to advance control. Pathog Glob Health 2024; 118:1-24. [PMID: 37872790 PMCID: PMC10769148 DOI: 10.1080/20477724.2023.2272095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023] Open
Abstract
Neglected tropical diseases (NTDs) have become important public health threats that require multi-faceted control interventions. As late treatment and management of NTDs contribute significantly to the associated burdens, early diagnosis becomes an important component for surveillance and planning effective interventions. This review identifies common NTDs and highlights the progress in the development of diagnostics for these NTDs. Leveraging existing technologies to improve NTD diagnosis and improving current operational approaches for deployment of developed diagnostics are crucial to achieving the 2030 NTD elimination target. Point-of-care NTD (POC-NTD) diagnostic tools are recommended preferred diagnostic options in resource-constrained areas for mapping risk zones and monitoring treatment efficacy. However, few are currently available commercially. Technical training of remote health care workers on the use of POC-NTD diagnostics, and training of health workers on the psychosocial consequences of these diagnostics are critical in harnessing POC-NTD diagnostic potential. While the COVID-19 pandemic has challenged the possibility of achieving NTD elimination in 2030 due to the disruption of healthcare services and dwindling financial support for NTDs, the possible contribution of NTDs in exacerbating COVID-19 pandemic should motivate NTD health system strengthening.
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Affiliation(s)
- Oyetunde T. Oyeyemi
- Department of Biosciences and Biotechnology, University of Medical Sciences, Ondo, Nigeria
- Department of Biological Sciences, Old Dominion University, Virginia, USA
| | - Olumide Ogundahunsi
- The Central Office for Research and Development (CORD), University of Medical Sciences, Ondo, Nigeria
| | - Mirjam Schunk
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU) institution, Munich, Germany
| | - Ramzy G. Fatem
- Schistosome Biological Supply Center, Theodor Bilharz Research Institute, Giza, Egypt
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Gordon CA, Utzinger J, Muhi S, Becker SL, Keiser J, Khieu V, Gray DJ. Strongyloidiasis. Nat Rev Dis Primers 2024; 10:6. [PMID: 38272922 DOI: 10.1038/s41572-023-00490-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
Strongyloidiasis is a neglected tropical disease caused primarily by the roundworm Strongyloides stercoralis. Strongyloidiasis is most prevalent in Southeast Asia and the Western Pacific. Although cases have been documented worldwide, global prevalence is largely unknown due to limited surveillance. Infection of the definitive human host occurs via direct skin penetration of the infective filariform larvae. Parasitic females reside in the small intestine and reproduce via parthenogenesis, where eggs hatch inside the host before rhabditiform larvae are excreted in faeces to begin the single generation free-living life cycle. Rhabditiform larvae can also develop directly into infectious filariform larvae in the gut and cause autoinfection. Although many are asymptomatic, infected individuals may report a range of non-specific gastrointestinal, respiratory or skin symptoms. Autoinfection may cause hyperinfection and disseminated strongyloidiasis in immunocompromised individuals, which is often fatal. Diagnosis requires direct examination of larvae in clinical specimens, positive serology or nucleic acid detection. However, there is a lack of standardization of techniques for all diagnostic types. Ivermectin is the treatment of choice. Control and elimination of strongyloidiasis will require a multifaceted, integrated approach, including highly sensitive and standardized diagnostics, active surveillance, health information, education and communication strategies, improved water, sanitation and hygiene, access to efficacious treatment, vaccine development and better integration and acknowledgement in current helminth control programmes.
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Affiliation(s)
- Catherine A Gordon
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia.
- Faculty of Medicine, University of Queensland, St Lucia, Brisbane, Queensland, Australia.
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Stephen Muhi
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, Victoria, Australia
- The University of Melbourne, Department of Microbiology and Immunology, Parkville, Victoria, Australia
| | - Sören L Becker
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Virak Khieu
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Darren J Gray
- Population Health Program, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia
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9
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Wisetmora A, Artchayasawat A, Laummaunwai P, Pitaksakulrat O, Wattanawong O, Boonmars T. Formalin-fixed stool improves the performance of the Kato-Katz method. Vet World 2024; 17:99-107. [PMID: 38406352 PMCID: PMC10884569 DOI: 10.14202/vetworld.2024.99-107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/14/2023] [Indexed: 02/27/2024] Open
Abstract
Background and Aim Parasitic infections are a public health problem worldwide, including in Thailand. An epidemiological survey for helminthiasis based on stool examination uses the Kato-Katz method as recommended by the World Health Organization. Limitations of this method include the need for fresh stool, time requirement, and lack of quality control. The aim of this study was to enhance the efficiency of the Kato-Katz technique using formalin and glycerol solutions and to implement specimen preparation in fieldwork. Materials and Methods For the Kato-Katz method, stool samples were divided into formalin-fixed and unfixed groups at various time points and processes. Fresh echinostome eggs were added to each stool group. Incubation with glycerol increased the clearing process. Each group was observed and photographed using a light microscope. Parasite eggs were imaged and compared using the standard Kato-Katz method. Results Visualization of echinostome eggs from formalin-fixed stool slides was significantly better than that from unfixed stool slides (p < 0.01). Stool samples fixed for 7 days retained normal echinostome eggs morphology. Incubation with glycerol for 1 h resulted in increased Kato-Katz performance by digesting the stool content and enhancing egg observation. Moreover, the results of the Kato-Katz method using fixed and fixed stool plus glycerol for natural helminth infection showed good quality of Opisthorchis viverrini and Taenia egg visualization and normal morphology with a clear background of slides. Conclusion Formalin-fixed stool could be more suitable than fresh stool for the Kato-Katz method.
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Affiliation(s)
- Ampas Wisetmora
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
- Division of General Communicable Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, 11000, Thailand
| | - Atchara Artchayasawat
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Porntip Laummaunwai
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Opal Pitaksakulrat
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Oranard Wattanawong
- Office of Diseases Prevention and Control 4 Saraburi, Ministry of Public Health, Saraburi, 18120, Thailand
| | - Thidarut Boonmars
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
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10
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Mazigo HD, Justine NC, Bhuko J, Rubagumya S, Basinda N, Zinga MM, Ruganuza D, Misko VR, Briet M, Legein F, De Malsche W. High Specificity but Low Sensitivity of Lab-on-a-Disk Technique in Detecting Soil-Transmitted Helminth Eggs among Pre- and School-Aged Children in North-Western Tanzania. Trop Med Infect Dis 2023; 9:5. [PMID: 38276635 PMCID: PMC10818991 DOI: 10.3390/tropicalmed9010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024] Open
Abstract
An estimated 1.5 billion people are infected with soil-transmitted helminths (hookworms, Ascaris lumbricoides and Trichuris trichiura). These infections are targeted for elimination by the World Health Organization (WHO) by 2030, with the main interventions being mass drug administration using albendazole or mebendazole. Tanzania is one of the endemic countries; it has been implementing MDA to school-aged children for more than a decade and the infection prevalence and intensity of infection have declined. Thus, at this point, the monitoring and evaluation of infection prevalence and intensity of infections, and assessing drug efficacy is crucial and requires accurate diagnostic tests. The currently used standard diagnostic test, the Kato-Katz (KK) technique, has several limitations and the WHO is calling for the development and evaluation of new diagnostic tests. The Lab-on-a-disk (LOD) was developed and tested in the endemic areas of north-western Tanzania to evaluate its sensitivity and specificity using KK and the formol-ether concentration technique. The results showed that when using a duplicate KK slide, the LOD had a sensitivity and specificity of 37.2% (95% CI: 30.7-43.9) and 67.3% (95% CI: 63.1-71.3%). Using four KK slides as a standard technique, the overall sensitivity and specificity were 37.7% (95% CI: 33.1-42.6) and 70.7% (95% CI: 65.5-75.6). The LOD attained high specificity but low sensitivity especially in detecting eggs of Trichuris trichiura. The LOD technique has potential as a promising diagnostic test, but its sensitivity still requires improvement.
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Affiliation(s)
- Humphrey D. Mazigo
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Nyanda C. Justine
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Jeffer Bhuko
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Sarah Rubagumya
- Department of Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, Morogoro P.O. Box 3000, Tanzania;
| | - Namanya Basinda
- Department of Community Medicine, School of Public Health, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania;
| | - Maria M. Zinga
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Deodatus Ruganuza
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania; (N.C.J.); (J.B.); (M.M.Z.); (D.R.)
| | - Vyacheslav R. Misko
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
| | - Matthieu Briet
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
| | - Filip Legein
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
| | - Wim De Malsche
- µFlow Group, Department of Bioengineering Sciences, Vrije Universiteit Brussel, 1050 Brussels, Belgium; (V.R.M.); (M.B.); (F.L.)
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Buonfrate D, Bradbury RS, Watts MR, Bisoffi Z. Human strongyloidiasis: complexities and pathways forward. Clin Microbiol Rev 2023; 36:e0003323. [PMID: 37937980 PMCID: PMC10732074 DOI: 10.1128/cmr.00033-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 08/11/2023] [Indexed: 11/09/2023] Open
Abstract
Strongyloidiasis is a World Health Organization neglected tropical disease usually caused by Strongyloides stercoralis, a parasitic worm with a complex life cycle. Globally, 300-600 million people are infected through contact with fecally contaminated soil. An autoinfective component of the life cycle can lead to chronic infection that may be asymptomatic or cause long-term symptoms, including malnourishment in children. Low larval output can limit the sensitivity of detection in stool, with serology being effective but less sensitive in immunocompromise. Host immunosuppression can trigger catastrophic, fatal hyperinfection/dissemination, where large numbers of larvae pierce the bowel wall and disseminate throughout the organs. Stable disease is effectively treated by single-dose ivermectin, with disease in immunocompromised patients treated with multiple doses. Strategies for management include raising awareness, clarifying zoonotic potential, the development and use of effective diagnostic tests for epidemiological studies and individual diagnosis, and the implementation of treatment programs with research into therapeutic alternatives and medication safety.
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Affiliation(s)
- Dora Buonfrate
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy
| | - Richard S. Bradbury
- School of Health and Life Sciences, Federation University Australia, Berwick, Victoria, Australia
| | - Matthew R. Watts
- Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research – New South Wales Health Pathology and Sydney Institute for Infectious Diseases, Westmead Hospital, University of Sydney, Sydney, New South Wales, Australia
| | - Zeno Bisoffi
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy
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Crego-Vicente B, Febrer-Sendra B, Nindia A, Pessela A, Aixut S, Martínez-Campreciós J, Mediavilla A, Silgado A, Sulleiro E, Treviño B, Molina I, Muro A, Salvador F, Fernández-Soto P. First field study using Strong-LAMP for diagnosis of strongyloidiasis in Cubal, Angola. Parasit Vectors 2023; 16:393. [PMID: 37907997 PMCID: PMC10619288 DOI: 10.1186/s13071-023-06009-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/10/2023] [Indexed: 11/02/2023] Open
Abstract
BACKGROUND Strongyloides stercoralis infection is a common neglected tropical disease distributed worldwide, mainly in tropical and subtropical climates. The impact of S. stercoralis infections on human health ranges from mild asymptomatic infections to chronic strongyloidiasis unnoticeable until the host is immunosuppressed. In severe strongyloidiasis, a syndrome of hyperinfection and larval dissemination to various organs can occur with high mortality rates. The diagnosis of strongyloidiasis is challenging because of the absence of a single standard reference test with high sensitivity and specificity, which also makes it difficult to estimate the accuracy of other diagnostic tests. This study aimed to evaluate, for the first time, the use of an easy-to-perform loop-mediated isothermal amplification (LAMP) colorimetric assay (named Strong-LAMP) for the molecular screening of strongyloidiasis in stool samples from patients in a low-resource endemic area in Cubal, Angola. To compare different LAMP application scenarios, the performance of the Strong-LAMP under field conditions in Angola was reassessed in a well-equipped reference laboratory in Spain and compared with a quantitative polymerase chain reaction (qPCR) method. METHODS A total of 192 stool samples were collected from adult population in Cubal, Angola, and examined by parasitological methods (direct saline microscopy and Baermann's technique). DNA was extracted from each stool sample using a commercial kit and tested by the colorimetric Strong-LAMP assay for the detection of Strongyloides spp. under field conditions. Furthermore, all samples were shipped to a well-equipped laboratory in Spain, reanalysed by the same procedure and compared with a qPCR method. The overall results after testing were compared. RESULTS Strongyloides stercoralis larvae were identified by direct saline microscopy and Baermann in a total of 10/192 (5.2%) and 18/192 (9.4%) stool samples, respectively. Other helminth and protozoan species were also identified. The Strong-LAMP-positive results were visually detected in 69/192 (35.9%) stool samples. The comparison of Strong-LAMP results in field conditions and at a reference laboratory matched in a total of 146/192 (76.0%) samples. A total of 24/192 (12.5%) stool samples tested positive by qPCR. CONCLUSIONS This is the first study in which colorimetric Strong-LAMP has been clinically evaluated in a resource-poor strongyloidiasis endemic area. Strong-LAMP has been shown to be more effective in screening for strongyloidiasis than parasitological methods under field conditions and qPCR in the laboratory. Our Strong-LAMP has proven to be a field-friendly and highly accurate molecular test for the diagnosis of strongyloidiasis.
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Affiliation(s)
- Beatriz Crego-Vicente
- Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca-Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), Faculty of Pharmacy, University of Salamanca, Salamanca, Spain
| | - Begoña Febrer-Sendra
- Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca-Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), Faculty of Pharmacy, University of Salamanca, Salamanca, Spain
| | | | | | | | - Joan Martínez-Campreciós
- Hospital Nossa Senhora da Paz, Cubal, Angola
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Alejandro Mediavilla
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS, Barcelona, Spain
| | - Aroa Silgado
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS, Barcelona, Spain
| | - Elena Sulleiro
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS, Barcelona, Spain
| | - Begoña Treviño
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- International Health Unit Vall d'Hebron-Drassanes, Infectious Diseases Department, Vall d'Hebron University Hospital, PROSICS, Barcelona, Spain
| | - Israel Molina
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- International Health Unit Vall d'Hebron-Drassanes, Infectious Diseases Department, Vall d'Hebron University Hospital, PROSICS, Barcelona, Spain
| | - Antonio Muro
- Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca-Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), Faculty of Pharmacy, University of Salamanca, Salamanca, Spain
| | - Fernando Salvador
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain.
- International Health Unit Vall d'Hebron-Drassanes, Infectious Diseases Department, Vall d'Hebron University Hospital, PROSICS, Barcelona, Spain.
| | - Pedro Fernández-Soto
- Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca-Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), Faculty of Pharmacy, University of Salamanca, Salamanca, Spain.
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Leutenegger CM, Lozoya CE, Tereski J, Andrews J, Mitchell KD, Meeks C, Willcox JL, Freeman G, Richmond HL, Savard C, Evason MD. Comparative study of a broad qPCR panel and centrifugal flotation for detection of gastrointestinal parasites in fecal samples from dogs and cats in the United States. Parasit Vectors 2023; 16:288. [PMID: 37587483 PMCID: PMC10433665 DOI: 10.1186/s13071-023-05904-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/27/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND For decades, zinc sulfate centrifugal fecal flotation microscopy (ZCF) has been the mainstay technique for gastrointestinal (GI) parasite screening at veterinary clinics and laboratories. Elsewhere, PCR has replaced microscopy because of generally increased sensitivity and detection capabilities; however, until recently it has been unavailable commercially. Therefore, the primary aim of this study was to compare the performance of real-time PCR (qPCR) and ZCF for fecal parasite screening. Secondary aims included further characterization of markers for hookworm treatment resistance and Giardia spp. assemblages with zoonotic potential and qPCR optimization. METHODS A convenience sampling of 931 canine/feline fecal samples submitted to a veterinary reference laboratory for routine ZCF from the Northeast US (11/2022) was subsequently evaluated by a broad qPCR panel following retention release. Detection frequency and agreement (kappa statistics) were evaluated between ZCF and qPCR for seven GI parasites [hookworm/(Ancylostoma spp.), roundworm/(Toxocara spp.), whipworm/(Trichuris spp.), Giardia duodenalis, Cystoisospora spp., Toxoplasma gondii, and Tritrichomonas blagburni] and detections per sample. Total detection frequencies were compared using a paired t-test; positive sample and co-infection frequencies were compared using Pearson's chi-squared test (p ≤ 0.05 significant) and qPCR frequency for hookworm benzimidazole (BZ) resistance (F167Y) and zoonotic Giardia spp. assemblage markers calculated. Confirmatory testing, characterization, and qPCR optimization were carried out with Sanger sequencing. RESULTS qPCR detected a significantly higher overall parasite frequency (n = 679) compared to ZCF (n = 437) [p = < 0.0001, t = 14.38, degrees-of-freedom (df) = 930] and 2.6 × the co-infections [qPCR (n = 172) vs. ZCF (n = 66)], which was also significant (p = < 0.0001, X2 = 279.49; df = 1). While overall agreement of parasite detection was substantial [kappa = 0.74; (0.69-0.78], ZCF-undetected parasites reduced agreement for individual and co-infected samples. qPCR detected markers for Ancylostoma caninum BZ resistance (n = 5, 16.1%) and Giardia with zoonotic potential (n = 22, 9.1%) as well as two parasites undetected by ZCF (T. gondii/T. blagburni). Sanger sequencing detected novel roundworm species, and qPCR optimization provided detection beyond ZCF. CONCLUSIONS These results demonstrate the statistically significant detection frequency advantage offered by qPCR compared to routine ZCF for both single and co-infections. While overall agreement was excellent, this rapid, commercially available qPCR panel offers benefits beyond ZCF with detection of markers for Giardia assemblages with zoonotic potential and hookworm (A. caninum) BZ resistance.
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Affiliation(s)
| | | | | | - Jan Andrews
- Antech Diagnostics, Inc, Fountain Valley, CA, USA
| | | | - Cathy Meeks
- Antech Diagnostics, Inc, Fountain Valley, CA, USA
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Hajizadeh F, Galeh TM, Hosseini SA, Shariatzadeh SA, Hematizadeh A, Javidnia J, Sadeghi M, Fakhar M, Gholami S. Investigating intestinal parasitic infections with emphasis on molecular identification of Strongyloides stercoralis and Trichostrongylus colubriformis in north of Iran. Parasite Epidemiol Control 2023; 22:e00312. [PMID: 37389283 PMCID: PMC10302123 DOI: 10.1016/j.parepi.2023.e00312] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/25/2023] [Accepted: 06/06/2023] [Indexed: 07/01/2023] Open
Abstract
Currently, parasitic infections are one of the important health problems in the world, especially in developing countries. This study aims to investigate intestinal parasites with an emphasis on molecular identification through the analysis of mitochondrial COX1 and ITS2 gene sequences of Strongyloides stercoralis (S. stercoralis) and Trichostrongylus spp. in north of Iran. Five hundred forty stool samples were collected from medical diagnostic laboratories affiliated with Mazandaran University of Medical Sciences in Sari city, north of Iran. First, all the samples were examined using direct smear, formalin-ether sedimentation, and trichrome staining technique. Suspected samples of Strongyloides larvae were cultured in agar plate. Then, DNA was extracted from samples containing Trichostrongylus spp. eggs and Strongyloides larvae. To amplify DNA, PCR was performed and the samples with a sharp band in electrophoresis were sequenced by Sanger method. Overall, the prevalence of parasitic infections in the study population was 5.4%. The highest and the lowest level of infection was observed with Trichostrongylus spp. and S. stercoralis at 3% and 0.2%, respectively. No traces of live Strongyloides larvae were seen in the culture medium of the agar plate. The six isolates obtained from the amplification of the ITS2 gene of Trichostrongylus spp. were sequenced, all of which were Trichostrongylus colubriformis. The sequencing results of COX1 gene indicated S. stercoralis. In the present study, the prevalence of intestinal parasitic infections in north of Iran has relatively decreased that its main reason can be due to the coronavirus epidemic and compliance with health principles. However, the prevalence of Trichostrongylus parasite was relatively high that it requires special attention to apply appropriate control and treatment strategies in this field.
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Affiliation(s)
- Fatemeh Hajizadeh
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | | | - Seyed Abdollah Hosseini
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyyed Ali Shariatzadeh
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Akram Hematizadeh
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Javad Javidnia
- Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mitra Sadeghi
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahdi Fakhar
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shirzad Gholami
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
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15
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Devyatov AA, Davydova EE, Luparev AR, Karseka SA, Shuryaeva AK, Zagainova AV, Shipulin GA. Design of a Protocol for Soil-Transmitted Helminths (in Light of the Nematode Toxocara canis) DNA Extraction from Feces by Combining Commercially Available Solutions. Diagnostics (Basel) 2023; 13:2156. [PMID: 37443549 DOI: 10.3390/diagnostics13132156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/02/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
One of the main challenges for the mass introduction of the molecular diagnostics of soil-transmitted helminths (STHs) into clinical practice is the lack of a generally recognized effective method for isolating parasitic DNA from fecal samples. In the present study, we assessed the effects of various pretreatment procedures on the efficiency of removing PCR inhibitors and extracting Toxocara canis DNA from feces. We evaluated the effectiveness of four destructive methods (bead beating, the action of temperature-dependent enzymes, freeze-heat cycles, and incubation in a lysis buffer) on the integrity of T. canis eggs and the efficiency of DNA extraction. Also, we evaluated the effects of prewashes and the use of commercial concentrators on DNA extraction from fecal samples contaminated with T. canis eggs. A bead beating procedure was sufficient to destroy the T. canis eggs, while the effects of enzymes and freeze-heat cycles did not lead to a significant destruction of the eggs or the release of Toxocara DNA. Helminth DNA isolation protocols that do not include a bead beating step are not preferred. The preconcentration of STH eggs from feces using a commercial concentrator and subsequent washing can significantly increase the yield of DNA from STHs and reduce PCR inhibition.
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Affiliation(s)
- Alexander A Devyatov
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
| | - Ekaterina E Davydova
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
| | - Andrey R Luparev
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
| | - Sofia A Karseka
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
| | - Anna K Shuryaeva
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
| | - Angelica V Zagainova
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
| | - German A Shipulin
- Federal State Budgetary Institution "Centre for Strategic Planning and Management of Biomedical Health Risks" of the Federal Medical Biological Agency, 10 bld 1, Pogodinskaya Str., 119121 Moscow, Russia
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16
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Wondimu H, Mihret M. Prevalence and Associated Factors of Intestinal Parasites among Food Handlers Working in Food Service Establishments in Northwest Ethiopia, 2022. J Parasitol Res 2023; 2023:3230139. [PMID: 37252034 PMCID: PMC10212672 DOI: 10.1155/2023/3230139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/31/2023] Open
Abstract
Background As in most of African countries, intestinal parasites have been widely distributed in Ethiopia and are among the 10 top causes of morbidity and mortality nationwide. Statistics for food-borne illness in various industrialized countries show that up to 60% of cases may be caused by poor food handling techniques and by contaminated food served in food service establishments. Epidemiological information on the prevalence of various intestinal parasitic infections in different regions/localities is a prerequisite to develop appropriate strategies. Objective This study aimed to determine the magnitude of intestinal parasites among food handlers working in different food service establishments in Gondar city. Methods A cross-sectional study was conducted with food handlers working in different food service establishments in Gondar city. Stool samples were collected from 350 food handlers and processed using the formol-ether concentration method and then microscopically examined for intestinal parasitic infections. Pre-tested and structured questionnaire was used to study the socio-demographic characteristics of food handlers. Chi-square test and p-value were used to assess the associations between risk factors and the parasite isolation rate. The p-value ≤0.05 was considered as statistically significant. Results Of the 350 food handlers, 160 (45.71%) had parasites. Among the isolated parasites, Ascaris lumbricoides was found to be the most prevalent parasite 35.63%, followed by hookworm 19.38%, Entamoeba histolytica/dispar 16.25%, Trichuris trichiura 10.00%, Strongyloides stercoralis 8.13%, Schistosoma mansoni 6.88%, and Cystoisospora belli, Hymenolepis nana, and Taenia species each accounting 1.25%. Conclusion The result of the study indicated that the magnitude of intestinal parasitosis among food handlers working at different levels of food establishments in Gondar, Ethiopia, was found to be high. Being at lower educational level and inactive role of the town's municipality are determined as a risk factor for parasitic positivity of food handlers.
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Affiliation(s)
- Hailegebriel Wondimu
- Department of Medical Laboratory, Debre Tabor Health Science College, Debre Tabor, Ethiopia
| | - Mestawut Mihret
- Department of Nursing, Debre Tabor Health Science College, Debre Tabor, Ethiopia
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17
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Ribado Meñe G, Dejon Agobé JC, Momo Besahà JC, Abaga Ondo Ndoho F, Abdulla S, Adegnika AA. Prevalence, intensity and associated risk factors of soil-transmitted helminth infections among individuals living in Bata district, Equatorial Guinea. PLoS Negl Trop Dis 2023; 17:e0011345. [PMID: 37196007 PMCID: PMC10228798 DOI: 10.1371/journal.pntd.0011345] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 05/30/2023] [Accepted: 04/28/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND Soil transmitted Helminths (STH) infections remain a public health concern worldwide, particularly in tropical and subtropical areas where these diseases are highly endemic. Knowing the prevalence and risk factors of the disease is crucial for efficient STH control strategies in endemic areas. The scarcity of epidemiological data on STH for Equatorial Guinea has motivated the decision to perform the present study. METHODS A cluster-based cross-sectional study was carried out in Bata district from November 2020 to January 2021. Stool samples were collected for the diagnostic of STH infections using Kato-Katz technique. Descriptive statistics was performed for determination of STH prevalence and intensity, while logistic regression models were used to assess the risk factors associated with STH infections. RESULTS A total of 340 participants were included in the study with a mean age of 24 years (SD = 23.7) and 1.2 female-to-male sex-ratio. The overall prevalence of any STH was 60% (95%CI: 55-65). The most prevalent species were Ascaris lumbricoides (43%, 95%CI: 37-48) and Trichuris trichiura (40%, 95%CI: 35-46). Intensity of infection were mainly light to moderate. A trend of association was observed between age and any STH infection (overall p-value = 0.07), with a significant difference observed between children aged 5-14 years as compared to those aged 1-4 (aOR 2.12; 95%CI: 1.02-4.43, p-value = 0.04), while locality was significantly associated with STH infection (overall p-value<0.001) with a higher odds observed for peri-urban area as compared to urban area (aOR 4.57; 95%CI: 2.27-9.60, p-value<0.001). CONCLUSION Bata district is a high STH transmission area, where school-aged children and peri-urban areas are associated with a higher risk of any STH infection. This situation calls for a full implementation of the WHO recommendations for STH control; mass drug administration of anthelminthic twice a year to the whole population with great attention to school age children, and prioritizing peri-urban areas where safe water, improve sanitation, and hygiene education should be implemented to achieve a better control.
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Affiliation(s)
- Gertrudis Ribado Meñe
- Department of Environmental Education and Outreach, Faculty of Environment, National University of Equatorial Guinea, Malabo, Equatorial Guinea
- Ecole Doctorale Régional de l’Afrique centrale en infectiologie Tropicale, Franceville, Gabon
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Jean Claude Dejon Agobé
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tubingen and Partner site Tubingen, German Center for Infection Research, Tubingen, Germany
| | - Juan Carlos Momo Besahà
- Department of health and safety, Bioko Island Malaria Elimination project in Equatorial Guinea, Malabo, Equatorial Guinea
| | | | - Salim Abdulla
- Department of intervention, Ifakara Health Institute, Dar–es- salaam, Tanzania
| | - Ayôla Akim Adegnika
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tubingen and Partner site Tubingen, German Center for Infection Research, Tubingen, Germany
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- Fondation pour la Recherche Scientifique, (FORS) Cotonou, Benin
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Chan AHE, Thaenkham U. From past to present: opportunities and trends in the molecular detection and diagnosis of Strongyloides stercoralis. Parasit Vectors 2023; 16:123. [PMID: 37041645 PMCID: PMC10088203 DOI: 10.1186/s13071-023-05763-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 03/30/2023] [Indexed: 04/13/2023] Open
Abstract
Strongyloides stercoralis is a soil-transmitted helminth that is mainly found in the tropical and subtropical regions and affects approximately 600 million people globally. The medical importance of strongyloidiasis lies in its capacity to remain asymptomatic and chronically unnoticed until the host is immunocompromised. Additionally, in severe strongyloidiasis, hyperinfection syndrome and larva dissemination to various organs can occur. Parasitological techniques such as Baermann-Moraes and agar plate culture to detect larvae in stool samples are the current gold standard. However, the sensitivity might be inadequate, especially with reduced worm burden. Complementing parasitological techniques, immunological techniques including immunoblot and immunosorbent assays are employed, with higher sensitivity. However, cross-reactivity to other parasites may occur, hampering the assay's specificity. Recently, advances in molecular techniques such as polymerase chain reaction and next-generation sequencing technology have provided the opportunity to detect parasite DNA in stool, blood, and environmental samples. Molecular techniques, known for their high sensitivity and specificity, have the potential to circumvent some of the challenges associated with chronicity and intermittent larval output for increased detection. Here, as S. stercoralis was recently included by the World Health Organization as another soil-transmitted helminth targeted for control from 2021 to 2030, we aimed to present a review of the current molecular techniques for detecting and diagnosing S. stercoralis in a bid to consolidate the molecular studies that have been performed. Upcoming molecular trends, especially next-generation sequencing technologies, are also discussed to increase the awareness of its potential for diagnosis and detection. Improved and novel detection methods can aid in making accurate and informed choices, especially in this era where infectious and non-infectious diseases are increasingly commonplace.
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Affiliation(s)
| | - Urusa Thaenkham
- Department of Helminthology, Mahidol University, Bangkok, Thailand
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Maurelli MP, Pepe P, Gualdieri L, Bosco A, Cringoli G, Rinaldi L. Improving Diagnosis of Intestinal Parasites Towards a Migrant-Friendly Health System. CURRENT TROPICAL MEDICINE REPORTS 2022. [DOI: 10.1007/s40475-022-00280-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
Purpose of Review
This study describes the results obtained by the World Health Organization (WHO) collaborating centre (CC) for the diagnosis of intestinal helminths and protozoa (WHO CC ITA-116) during the first 2 years of its activity on (i) the prevalence of intestinal parasites in migrants in southern Italy and (ii) the development and application of new diagnostic tools for intestinal helminths (e.g. FLOTAC, Mini-FLOTAC Kit 200 tests, Kubic FLOTAC microscope (KFM)).
Recent Findings
Almost 23.3% of migrants examined were positive for at least one intestinal parasite. Moreover, a significant correlation was found between the duration of stay in Italy and positivity for intestinal parasites. The results of the comparison between diagnostic techniques showed a perfect agreement between FLOTAC and Mini-FLOTAC Kit 200 tests whereas no statistically significant differences were found between the count of helminth eggs obtained by Mini-FLOTAC with optical microscope and KFM.
Summary
The results obtained by WHO CC ITA-116 during the first 2 years of its activity provide important information on innovations in parasitological diagnosis and add data to the parasitological scenario of migrants arriving in southern Italy, highlighting the importance of regular parasitological monitoring.
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Advantages and Limitations of Microscopy and Molecular Detections for Diagnosis of Soil-transmitted Helminths: An Overview. Helminthologia 2022; 59:321-340. [PMID: 36875683 PMCID: PMC9979072 DOI: 10.2478/helm-2022-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 10/31/2022] [Indexed: 02/05/2023] Open
Abstract
World Health Organization (WHO) reported that over 1.5 billion people are infected by soil-transmitted helminths (STH) worldwide in sub-Saharan Africa, the United States of America, China, and East Asia. Heavy infections and polyparasitism are associated with higher morbidity rates, and the patients are exposed to increased vulnerability to other diseases. Therefore, accurate diagnosis followed by mass treatment for morbidity control is necessary.STH diagnosis commonly involves the microscopic observation of the presence of the STH eggs and larvae in the faecal samples. Furthermore, molecular approaches are increasingly utilised in monitoring and surveillance as they show higher sensitivity. Their capability to differentiate hookworm species is an advantage over the Kato-Katz technique. This review discusses the advantages and limitations of microscopy and various molecular tools used for STH detection.
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Buonfrate D, Tamarozzi F, Paradies P, Watts MR, Bradbury RS, Bisoffi Z. The diagnosis of human and companion animal Strongyloides stercoralis infection: Challenges and solutions. A scoping review. ADVANCES IN PARASITOLOGY 2022; 118:1-84. [PMID: 36088083 DOI: 10.1016/bs.apar.2022.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Strongyloidiasis is the infection caused by soil-transmitted nematodes of Strongyloides species, infecting humans and some animals. Strongyloides stercoralis is the species with most clinical and epidemiological relevance in humans and dogs, due to its high prevalence and its capacity of inducing a life-threatening hyperinfection. Diagnosis of strongyloidiasis is challenging, due to the absence of a single reference standard test with high sensitivity and specificity, which also hampers the estimation of the accuracy of other diagnostic tests. In this chapter, we review the deployment and performance of the parasitological, immunological, molecular tests for the diagnosis of strongyloidiasis in humans and in dogs. Further, we comment the available evidence from genotyping studies that have addressed the zoonotic potential of S. stercoralis. Finally, we discuss the use of different diagnostic methods in relation to the purpose (i.e., screening, individual diagnosis, inclusion in a clinical trial) and the setting (endemic/non-endemic areas) and report the accuracy figures reported by systematic reviews on either parasitological, serological or molecular techniques published in literature.
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Affiliation(s)
- Dora Buonfrate
- Department of Infectious Tropical diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy.
| | - Francesca Tamarozzi
- Department of Infectious Tropical diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy
| | - Paola Paradies
- Department of Emergency and Organs Transplantation, Veterinary Section, Campus of Veterinary Medicine, University of Bari, Bari, Italy
| | - Matthew R Watts
- Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research - New South Wales Health Pathology and Sydney Institute for Infectious Diseases, Westmead Hospital, University of Sydney, Sydney, New South Wales, Australia
| | - Richard S Bradbury
- School of Health and Life Sciences, Federation University Australia, Berwick, VC, Australia
| | - Zeno Bisoffi
- Department of Infectious Tropical diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy; Department of Diagnostics and Public Health, University of Verona, Verona, Italy
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22
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Samenjo KT, Bengtson M, Onasanya A, Zambrano JCI, Oladunni O, Oladepo O, van Engelen J, Diehl JC. Stakeholders’ Perspectives on the Application of New Diagnostic Devices for Urinary Schistosomiasis in Oyo State, Nigeria: A Q-Methodology Approach. GLOBAL HEALTH: SCIENCE AND PRACTICE 2022; 10:GHSP-D-21-00780. [PMID: 36041843 PMCID: PMC9426976 DOI: 10.9745/ghsp-d-21-00780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/31/2022] [Indexed: 11/16/2022]
Abstract
New diagnostic devices for schistosomiasis should be designed to function best within the local endemic health care context and support stakeholders at various levels of the health care system in performing the tasks to help control and eventually eliminate schistosomiasis. Urinary schistosomiasis is a waterborne parasitic infection caused by Schistosoma haematobium that affects approximately 30 million people annually in Nigeria. Treatment and eradication of this infection require effective diagnostics. However, current diagnostic tests have critical shortcomings and consequently are of limited value to stakeholders throughout the health care system who are involved in targeting the diagnosis and subsequent control of schistosomiasis. New diagnostic devices that fit the local health care infrastructure and support the different stakeholder diagnostic strategies remain a critical need. This study focuses on understanding, by means of Q-methodology, the context of use and application of a new diagnostic device that is needed to effectively diagnose urinary schistosomiasis in Oyo State, Nigeria. Q-methodology is a technique that investigates subjectivity by exploring how stakeholders rank-order opinion statements about a phenomenon. In this study, 40 statements were administered to evaluate stakeholder perspectives on the context of use and application of potential new diagnostic devices and how these perspectives or viewpoints are shared with other stakeholders. Potential new diagnostic devices will need to be deployable to remote or distant communities, be affordable, identify and confirm infection status before treatment in patients whose diagnosis of urinary schistosomiasis is based on self-reporting, and equip health care facilities with diagnostic devices optimized for the local setting while requiring local minimal infrastructural settings. Similarly, the context of use and application of a potential new diagnostic device for urinary schistosomiasis is primarily associated with the tasks stakeholders throughout the health care system perform or procedures employed. These findings will guide the development of new diagnostic devices for schistosomiasis that match the contextual landscape and diagnostic strategies in Oyo.
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Affiliation(s)
- Karlheinz Tondo Samenjo
- Department of Sustainable Design Engineering, Faculty of Industrial Design Engineering, Delft University of Technology, Delft, Netherlands.
| | - Michel Bengtson
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Adeola Onasanya
- Department of Sustainable Design Engineering, Faculty of Industrial Design Engineering, Delft University of Technology, Delft, Netherlands
| | - Juan Carlo Intriago Zambrano
- Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands
| | - Opeyemi Oladunni
- Department of Health Promotion and Education, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Oladimeji Oladepo
- Department of Health Promotion and Education, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Jo van Engelen
- Department of Sustainable Design Engineering, Faculty of Industrial Design Engineering, Delft University of Technology, Delft, Netherlands
| | - Jan-Carel Diehl
- Department of Sustainable Design Engineering, Faculty of Industrial Design Engineering, Delft University of Technology, Delft, Netherlands
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Affordable artificial intelligence-based digital pathology for neglected tropical diseases: A proof-of-concept for the detection of soil-transmitted helminths and Schistosoma mansoni eggs in Kato-Katz stool thick smears. PLoS Negl Trop Dis 2022; 16:e0010500. [PMID: 35714140 PMCID: PMC9258839 DOI: 10.1371/journal.pntd.0010500] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 07/06/2022] [Accepted: 05/16/2022] [Indexed: 11/19/2022] Open
Abstract
Background
With the World Health Organization’s (WHO) publication of the 2021–2030 neglected tropical diseases (NTDs) roadmap, the current gap in global diagnostics became painfully apparent. Improving existing diagnostic standards with state-of-the-art technology and artificial intelligence has the potential to close this gap.
Methodology/Principal findings
We prototyped an artificial intelligence-based digital pathology (AI-DP) device to explore automated scanning and detection of helminth eggs in stool prepared with the Kato-Katz (KK) technique, the current diagnostic standard for diagnosing soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura and hookworms) and Schistosoma mansoni (SCH) infections. First, we embedded a prototype whole slide imaging scanner into field studies in Cambodia, Ethiopia, Kenya and Tanzania. With the scanner, over 300 KK stool thick smears were scanned, resulting in total of 7,780 field-of-view (FOV) images containing 16,990 annotated helminth eggs (Ascaris: 8,600; Trichuris: 4,083; hookworms: 3,623; SCH: 684). Around 90% of the annotated eggs were used to train a deep learning-based object detection model. From an unseen test set of 752 FOV images containing 1,671 manually verified STH and SCH eggs (the remaining 10% of annotated eggs), our trained object detection model extracted and classified helminth eggs from co-infected FOV images in KK stool thick smears, achieving a weighted average precision (± standard deviation) of 94.9% ± 0.8% and a weighted average recall of 96.1% ± 2.1% across all four helminth egg species.
Conclusions/Significance
We present a proof-of-concept for an AI-DP device for automated scanning and detection of helminth eggs in KK stool thick smears. We identified obstacles that need to be addressed before the diagnostic performance can be evaluated against the target product profiles for both STH and SCH. Given that these obstacles are primarily associated with the required hardware and scanning methodology, opposed to the feasibility of AI-based results, we are hopeful that this research can support the 2030 NTDs road map and eventually other poverty-related diseases for which microscopy is the diagnostic standard.
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Human hookworms from Argentina: Differential diagnosis of Necator americanus and Ancylostoma duodenale in endemic populations from Buenos Aires and Misiones. Rev Argent Microbiol 2022; 54:268-281. [DOI: 10.1016/j.ram.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/23/2021] [Accepted: 05/02/2022] [Indexed: 11/22/2022] Open
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Using quantitative PCR to identify opportunities to strengthen soil-transmitted helminth control in Solomon Islands: A cross-sectional epidemiological survey. PLoS Negl Trop Dis 2022; 16:e0010350. [PMID: 35604904 PMCID: PMC9126411 DOI: 10.1371/journal.pntd.0010350] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 03/22/2022] [Indexed: 11/19/2022] Open
Abstract
Background The Kato-Katz microscopy technique is the global standard for assessment of soil-transmitted helminth (STH) burden. However, major limitations include its poor sensitivity, requirement for rapid sample processing, and inability to differentiate hookworm species nor detect Strongyloides spp. infections. We assessed the prevalence and intensity of STH species in Solomon Islands by conducting a province-wide survey using quantitative PCR (qPCR) for diagnosis, which can provide much better characterisation of STH burden than microscopy. Methodology/Principal findings We conducted a cross-sectional survey in 18 villages in Western Province to detect infections with six STH species and quantify intensity with three. We used linear mixed model regression to identify potential water, sanitation, and hygiene (WASH) and environmental risk factors for infection. We collected stool specimens from 830 village residents. Overall STH prevalence was 63.3% (range 27.5 to 91.5% across villages), led by Necator americanus (54.5% [range 17.5–89.4%]), followed by Ancylostoma ceylanicum (15.5% [range 2.8–45.8%]), Trichuris trichiura (9.1% [range 0–79.2%]), and Strongyloides spp. (3.2% [range 0–29.2%]). Most infections were of light intensity for N. americanus (85.7%) and T. trichiura (90.7%). Owning a household latrine was associated with a lower risk of N. americanus infection (AOR 0.41, 95% CI 0.24–0.68) while greater precipitation was linked to more common T. trichiura infection (AOR 1.14, 95% CI 1.04–1.25). Conclusion/Significance In this first large-scale population survey of STH in the Pacific using qPCR, we found evidence that ivermectin should be incorporated into STH control programmes because of the presence of T. trichiura and Strongyloides spp., both of which are poorly responsive to albendazole. Furthermore, One Health strategies are needed for improved A. ceylanicum and Strongyloides spp. control, WASH access and use should be improved to complement deworming programmes, and control efforts should ideally be expanded to entire communities. Trial registration ClinicalTrials.gov Australian and New Zealand Clinical Trials Registry ACTRN12618001086257. Routine assessments of the burden of intestinal worm infections rely on microscopy-based diagnostic methods, such as the Kato-Katz technique. However major limitations include its poor sensitivity, requirement for rapid sample processing, and inability to differentiate individual hookworm species and detect Strongyloides spp. infections. It is important to assess the burden of each of these infections to design control approaches beyond the current core strategy of albendazole preventive chemotherapy. Use of qPCR for diagnosis could address these gaps because it can distinguish all relevant intestinal worm species. We completed a province-wide intestinal worm infections prevalence survey using qPCR in Western Province, Solomon Islands. Overall prevalence was extremely high (62.5%). We identified a high burden of Necator americanus (54.5%) and detected Ancylostoma ceylanicum (15.5%), Trichuris trichiura (9.1%), and Strongyloides spp. (3.2%) infections. Increased age and precipitation were associated with higher prevalence of infection, while owning a household latrine was associated with lower odds of N. americanus infection. Our findings support the need to incorporate ivermectin into deworming programmes for Strongyloides spp. and T. trichiura control as these species are poorly responsive to albendazole, implement One Health strategies to address the zoonotic A. ceylanicum and Strongyloides spp., and expand control efforts to reach entire communities. WASH access should also be improved to complement deworming programmes.
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26
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Kazienga A, Coffeng LE, de Vlas SJ, Levecke B. Two-stage lot quality assurance sampling framework for monitoring and evaluation of neglected tropical diseases, allowing for imperfect diagnostics and spatial heterogeneity. PLoS Negl Trop Dis 2022; 16:e0010353. [PMID: 35394996 PMCID: PMC9020685 DOI: 10.1371/journal.pntd.0010353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 04/20/2022] [Accepted: 03/28/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Monitoring and evaluation (M&E) is a key component of large-scale neglected tropical diseases (NTD) control programs. Diagnostic tests deployed in these M&E surveys are often imperfect, and it remains unclear how this affects the population-based program decision-making. METHODOLOGY We developed a 2-stage lot quality assurance sampling (LQAS) framework for decision-making that allows for both imperfect diagnostics and spatial heterogeneity of infections. We applied the framework to M&E of soil-transmitted helminth control programs as a case study. For this, we explored the impact of the diagnostic performance (sensitivity and specificity), spatial heterogeneity (intra-cluster correlation), and survey design on program decision-making around the prevalence decisions thresholds recommended by WHO (2%, 10%, 20% and 50%) and the associated total survey costs. PRINCIPAL FINDINGS The survey design currently recommended by WHO (5 clusters and 50 subjects per cluster) may lead to incorrect program decisions around the 2% and 10% prevalence thresholds, even when perfect diagnostic tests are deployed. To reduce the risk of incorrect decisions around the 2% prevalence threshold, including more clusters (≥10) and deploying highly specific diagnostic methods (≥98%) are the most-cost saving strategies when spatial heterogeneity is moderate-to-high (intra-cluster correlation >0.017). The higher cost and lower throughput of improved diagnostic tests are compensated by lower required sample sizes, though only when the cost per test is <6.50 US$ and sample throughput is ≥3 per hour. CONCLUSION/SIGNIFICANCE Our framework provides a means to assess and update M&E guidelines and guide product development choices for NTD. Using soil-transmitted helminths as a case study, we show that current M&E guidelines may severely fall short, particularly in low-endemic and post-control settings. Furthermore, specificity rather than sensitivity is a critical parameter to consider. When the geographical distribution of an NTD within a district is highly heterogeneous, sampling more clusters (≥10) may be required.
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Affiliation(s)
- Adama Kazienga
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Luc E. Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
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Aung E, Han KT, Gordon CA, Hlaing NN, Aye MM, Htun MW, Wai KT, Myat SM, Thwe TL, Tun A, Wangdi K, Li Y, Williams GM, Clements ACA, Vaz Nery S, McManus DP, Gray DJ. High prevalence of soil-transmitted helminth infections in Myanmar schoolchildren. Infect Dis Poverty 2022; 11:28. [PMID: 35272701 PMCID: PMC8908594 DOI: 10.1186/s40249-022-00952-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/21/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Achieving the elimination of soil-transmitted helminth (STH) infections requires a sufficient understanding of the current epidemiological status of STH endemicity. We aimed to examine the status of STH in Myanmar - a country with the eighth highest STH prevalence in the world, 10 years after instigation of the national deworming programme. METHODS In August 2016 we screened for STH infections using Kato Katz (KK) microscopy and real-time PCR (qPCR) in schoolchildren from the Bago Region township of Phyu, a STH sentinel site in Myanmar. Ten schools were randomly selected, and one stool sample each from a total of 264 students was examined. Prevalence and intensity of infection were calculated for each STH. RESULTS High prevalence of STH was identified in the study area with 78.8% of the schoolchildren infected with at least one STH by qPCR, and 33.3% by KK. The most prevalent STH was Trichuris trichiura, diagnosed by both KK (26.1%) and qPCR (67.1%), followed by Ascaris lumbricoides (15.5% KK; 54.9% qPCR). No hookworm infections were identified by KK; however, the qPCR analysis showed a high prevalence of Ancylostoma sp. infection (29.6%) with few Necator americanus (1.1%) infections. CONCLUSIONS Despite bi-annual deworming of schoolchildren in the fourth-grade and below, STH prevalence remains stubbornly high. These results informed the expansion of the Myanmar National STH control programme to include all school-aged children by the Ministry of Health and Sports in 2017, however further expansion to the whole community should be considered along with improving sanitation and hygiene measures. This would be augmented by rigorous monitoring and evaluation, including national prevalence surveys.
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Affiliation(s)
- Eindra Aung
- Department of Global Health, Research School of Population Health, Australian National University, Canberra, ACT, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Kay Thwe Han
- Parasitology Research Division, Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Catherine A Gordon
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | | | - Moe Moe Aye
- Department of Zoology, University of Yangon, Yangon, Myanmar
| | - Myo Win Htun
- Parasitology Research Division, Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Khin Thet Wai
- Parasitology Research Division, Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Su Mon Myat
- Department of Public Health, Ministry of Health and Sports, Nay Pyi Taw, Myanmar
| | - Thida Lay Thwe
- Department of Zoology, University of Yangon, Yangon, Myanmar
| | - Aung Tun
- Ministry of Health and Sports, Nay Pyi Taw, Myanmar
| | - Kinley Wangdi
- Department of Global Health, Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Yuesheng Li
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- Hunan Institute of Parasitic Diseases, World Health Organization Collaborating Centre for Research and Control On Schistosomiasis in Lake Region, Yueyang, China
| | - Gail M Williams
- School of Public Health, University of Queensland, Brisbane, QLD, Australia
| | - Archie C A Clements
- Department of Global Health, Research School of Population Health, Australian National University, Canberra, ACT, Australia
- Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Susana Vaz Nery
- Department of Global Health, Research School of Population Health, Australian National University, Canberra, ACT, Australia
- The Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | - Donald P McManus
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Darren J Gray
- Department of Global Health, Research School of Population Health, Australian National University, Canberra, ACT, Australia.
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28
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Borges JCG, Lima VFS, DA Silva EM, Dos Santos Lima D, Marmontel M, Carvalho VL, DA G Faustino MA, Cringolli G, Rinaldi L, Alves LC. Use of the FLOTAC technique as a new coproparasitological diagnostic method in aquatic mammals and comparison with traditional methods. AN ACAD BRAS CIENC 2022; 94:e20201184. [PMID: 35239771 DOI: 10.1590/0001-3765202220201184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/05/2020] [Indexed: 11/22/2022] Open
Abstract
The inadequate choice of a diagnostic method or the option for techniques that have low sensitivity and specificity may limit the diagnosis of parasitic agents that affect aquatic mammals. The aim of this study was to evaluate the performance of the FLOTAC technique and compare it with three traditional methods (Willis, sedimentation and centrifugation- flotation) used in the diagnosis of gastrointestinal parasites in aquatic mammals. For this, 129 fecal samples from 12 species were collected. Each sample was submitted to laboratory processing using the Willis, Hoffman techniques, Faust method and FLOTAC. Sensitivity, specificity, real prevalence, estimated prevalence, positive predictive value, negative predictive value, correct classification (accuracy) and incorrect classification were evaluated to compare the different diagnostic methods. The highest frequency of positive samples occurred using FLOTAC (46.51%), compared to Hoffman (23.25%), Faust (10.07%) and Willis techniques (6.97%). In the samples analyzed, the occurrence of Strongylidae eggs and Eimeriidae oocysts was frequently observed. The FLOTAC technique proved to be the most appropriate technique and due to its efficacy, is strongly recommended for coproparasitological evaluations in aquatic mammals.
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Affiliation(s)
- João Carlos G Borges
- Fundação Mamíferos Aquáticos, Rua Guimarães Peixoto, 75, 52051-305 Recife, PE, Brazil.,Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, 52171-900 Recife, PE, Brazil.,Programa de Pós-Graduação em Ecologia e Monitoramento Ambiental, Universidade Federal da Paraíba, Centro de Ciências Aplicadas e Educação, Campus IV, Avenida Elisabete, 160, Mangueira, 58297-000 Rio Tinto, PB, Brazil.,Grupo de Pesquisa em Mamíferos Aquáticos Amazônicos, Instituto de Desenvolvimento Sustentável Mamirauá, Estrada do Bexiga, 2584, Fonte Boa, Caixa Postal 38, 69553-225 Tefé, AM, Brazil
| | - Victor F S Lima
- Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, 52171-900 Recife, PE, Brazil
| | - Edson M DA Silva
- Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, 52171-900 Recife, PE, Brazil
| | - Danielle Dos Santos Lima
- Grupo de Pesquisa em Mamíferos Aquáticos Amazônicos, Instituto de Desenvolvimento Sustentável Mamirauá, Estrada do Bexiga, 2584, Fonte Boa, Caixa Postal 38, 69553-225 Tefé, AM, Brazil
| | - Miriam Marmontel
- Grupo de Pesquisa em Mamíferos Aquáticos Amazônicos, Instituto de Desenvolvimento Sustentável Mamirauá, Estrada do Bexiga, 2584, Fonte Boa, Caixa Postal 38, 69553-225 Tefé, AM, Brazil
| | - Vitor L Carvalho
- Associação de Pesquisa e Preservação de Ecossistemas Aquáticos - AQUASIS, Avenida Pintor João Figueiredo, s/n, 61627-210 Caucaia, CE, Brazil
| | | | - Giuseppe Cringolli
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, 80137, Naples, NA, Italy
| | - Laura Rinaldi
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, 80137, Naples, NA, Italy
| | - Leucio C Alves
- Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, 52171-900 Recife, PE, Brazil
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Abstract
Intestinal nematode infections caused by soil-transmitted helminths (STH), such as the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and the hookworms Ancylostoma duodenale, and Necator americanus, infect more than 1 billion people throughout the world. School-aged children tend to harbor the greatest numbers of intestinal worms, and as a result, experience more adverse health consequences, such as poor growth, anemia, and cognitive decline. Clinicians should maintain a high degree of suspicion in endemic areas when patients present with surgical abdomens, particularly children. Current antihelminthic drugs are moderately effective, but reinfection is possible. Global efforts are needed to eradicate STH infections.
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Affiliation(s)
- Angela F Veesenmeyer
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Pediatric Infectious Disease, Valleywise Health Medical Center, 2601 East Roosevelt Street, Phoenix, AZ 85008, USA.
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Scope and limitations of a multiplex conventional PCR for the diagnosis of S. stercoralis and hookworms. Braz J Infect Dis 2021; 25:101649. [PMID: 34774469 PMCID: PMC9392200 DOI: 10.1016/j.bjid.2021.101649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/23/2021] [Accepted: 10/17/2021] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES Describe the diagnostic characteristics of a conventional multiplex PCR for the diagnosis of S. stercoralis, N. americanus and Ancylostomas spp. METHODS Fecal samples were collected from a cross-sectional study in Orán department, Salta province, Argentina. The stool samples were analyzed using concentration-sedimentation, Harada Mori, McMaster, and Baermann techniques. DNA was extracted from 50 mg fecal sample using the FastPrep® Spin Kit for Soil. Three pairs of primers were used for the amplification of three products of 101, 330, and 577 base pairs (bp) for S. stercoralis, N. americanus and Ancylostoma spp, respectively. The sensitivity and analytical specificity of multiplex PCR were evaluated, as well as the sensitivity and diagnostic specificity, using a composite standard and Bayesian approach. RESULTS AND CONCLUSIONS Multiplex PCR did not present cross-reaction with other intestinal parasites, and the detection limit for multiplex PCR was between 2 and 20 pg of genomic DNA. In addition it presented a diagnostic sensitivity of 97.4% for S. stercoralis and 90.3% for hookworms with a specificity of 100% and 87.6%, respectively. PCR identified a higher proportion (p <0.01) of coinfections (15.3%) than microscopic techniques (3.5%). Also, multiplex PCR showed that there was a positive association between S. stercoralis and hookworms (odds ratio = 2.12). However, this association was due to N. americanus (odds ratio= 3.22), since no association was observed between S. stercoralis and Ancylostoma spp. Neither was an association observed between the two species of hookworms.
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Detection of six soil-transmitted helminths in human stool by qPCR- a systematic workflow. PLoS One 2021; 16:e0258039. [PMID: 34591904 PMCID: PMC8483301 DOI: 10.1371/journal.pone.0258039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/16/2021] [Indexed: 11/19/2022] Open
Abstract
Soil-transmitted helminths (STH) infect up to one-quarter of the global population, with a significant associated disease burden. The main human STH are: Ancylostoma spp. and Necator americanus (hookworms); Ascaris lumbricoides, Trichuris trichiura, and Strongyloides stercoralis. The aim of this study was to establish a scalable system for stool STH multiplex quantitative real-time polymerase chain reactions (qPCR). Stool samples collected in Fiji and preserved in potassium dichromate were transferred to Melbourne at ambient temperature. Samples were washed to remove potassium dichromate and DNA was extracted with the Mini-Beadbeater-24 and a column-based kit. A SYBR green qPCR to detect the vertebrate mitochondrial gene was used as a DNA extraction control. Samples were tested using a probe-based multiplex qPCR targeting A. lumbricoides, T. trichiura and S. stercoralis, and in a second multiplex reaction to detect hookworms to the species level (A. duodenale, A. ceylanicum, N. americanus). An internal amplification control in both multiplex assays was included to prevent false-negative results due to PCR inhibitors. Samples were homogenised for a single cycle of 40 seconds to release STH DNA and washed stool was stored for up to 15 weeks at -30°C without compromising DNA. Our multiplex qPCR detected multiple species of STH without reduced sensitivity compared to singleplex. qPCR data from 40 stools was validated against STH-positive stools determined by microscopy. We have developed and validated an efficient and staged system for detecting six clinically important STH affecting humans that could be easily implemented without advanced automation in any qPCR-capable laboratory.
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Sirima C, Bizet C, Hamou H, Červená B, Lemarcis T, Esteban A, Peeters M, Mpoudi Ngole E, Mombo IM, Liégeois F, Petrželková KJ, Boussinesq M, Locatelli S. Soil-transmitted helminth infections in free-ranging non-human primates from Cameroon and Gabon. Parasit Vectors 2021; 14:354. [PMID: 34225777 PMCID: PMC8259424 DOI: 10.1186/s13071-021-04855-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 06/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Zoonotic diseases are a serious threat to both public health and animal conservation. Most non-human primates (NHP) are facing the threat of forest loss and fragmentation and are increasingly living in closer spatial proximity to humans. Humans are infected with soil-transmitted helminths (STH) at a high prevalence, and bidirectional infection with NHP has been observed. The aim of this study was to determine the prevalence, genetic diversity, distribution and presence of co-infections of STH in free-ranging gorillas, chimpanzees and other NHP species, and to determine the potential role of these NHP as reservoir hosts contributing to the environmental sustenance of zoonotic nematode infections in forested areas of Cameroon and Gabon. METHODS A total of 315 faecal samples from six species of NHPs were analysed. We performed PCR amplification, sequencing and maximum likelihood analysis of DNA fragments of the internal transcribed spacer 2 (ITS2) nuclear ribosomal DNA to detect the presence and determine the genetic diversity of Oesophagostomum spp., Necator spp. and Trichuris spp., and of targeted DNA fragments of the internal transcribed spacer 1 (ITS1) to detect the presence of Ascaris spp. RESULTS Necator spp. infections were most common in gorillas (35 of 65 individuals), but also present in chimpanzees (100 of 222 individuals) and in one of four samples from greater spot-nosed monkeys. These clustered with previously described type II and III Necator spp. Gorillas were also the most infected NHP with Oesophagostomum (51/65 individuals), followed by chimpanzees (157/222 individuals), mandrills (8/12 samples) and mangabeys (7/12 samples), with O. stephanostomum being the most prevalent species. Oesophagostomum bifurcum was detected in chimpanzees and a red-capped mangabey, and a non-classified Oesophagostomum species was detected in a mandrill and a red-capped mangabey. In addition, Ternidens deminutus was detected in samples from one chimpanzee and three greater spot-nosed monkeys. A significant relative overabundance of co-infections with Necator and Oesophagostomum was observed in chimpanzees and gorillas. Trichuris sp. was detected at low prevalence in a gorilla, a chimpanzee and a greater spot-nosed monkey. No Ascaris was observed in any of the samples analysed. CONCLUSIONS Our results on STH prevalence and genetic diversity in NHP from Cameroon and Gabon corroborate those obtained from other wild NHP populations in other African countries. Future research should focus on better identifying, at a molecular level, the species of Necator and Oesophagostomum infecting NHP and determining how human populations may be affected by increased proximity resulting from encroachment into sylvatic STH reservoir habitats.
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Affiliation(s)
- C. Sirima
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - C. Bizet
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - H. Hamou
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - B. Červená
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 603 65 Brno, Czech Republic
- Department of Pathology and Parasitology, Faculty of Veterinary Medicine, University of Veterinary Sciences Brno, Brno, Czech Republic
| | - T. Lemarcis
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - A. Esteban
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - M. Peeters
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - E. Mpoudi Ngole
- Projet Prévention du Sida Au Cameroun (PRESICA) and Virology Laboratory IMPM/IRD, Yaoundé, Cameroon
| | - I. M. Mombo
- Centre Interdisciplinaire de Recherches Médicales de Franceville, BP 769, Franceville, Gabon
| | - F. Liégeois
- Present Address: Institut de Recherche Pour Le Développement (IRD), Maladies Infectieuses Et Vecteurs : Écologie, Génétique, Évolution et Contrôle (MIVEGEC), IRD 224-CNRS 5290–University of Montpellier, Montpellier, France
| | - K. J. Petrželková
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 603 65 Brno, Czech Republic
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - M. Boussinesq
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
| | - S. Locatelli
- Institut de Recherche Pour Le Développement (IRD), UMI 233-TransVIHMI-INSERM U1175–University of Montpellier, Montpellier, France
- Present Address: Institut de Recherche Pour Le Développement (IRD), Maladies Infectieuses Et Vecteurs : Écologie, Génétique, Évolution et Contrôle (MIVEGEC), IRD 224-CNRS 5290–University of Montpellier, Montpellier, France
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Keller L, Welsche S, Patel C, Sayasone S, Ali SM, Ame SM, Hattendorf J, Hürlimann E, Keiser J. Long-term outcomes of ivermectin-albendazole versus albendazole alone against soil-transmitted helminths: Results from randomized controlled trials in Lao PDR and Pemba Island, Tanzania. PLoS Negl Trop Dis 2021; 15:e0009561. [PMID: 34191812 PMCID: PMC8277064 DOI: 10.1371/journal.pntd.0009561] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/13/2021] [Accepted: 06/14/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Preventive chemotherapy is the cornerstone of soil-transmitted helminth (STH) control. Long-term outcomes and adequate treatment frequency of the recently recommended albendazole-ivermectin have not been studied to date. METHODOLOGY/PRINCIPAL FINDINGS Double-blind randomized controlled trials were conducted in Lao PDR, Pemba Island, Tanzania and Côte d'Ivoire between 2018 and 2020 to evaluate the efficacy and safety of ivermectin-albendazole versus albendazole-placebo in Trichuris trichiura-infected individuals aged 6 to 60. In the framework of this study, in Lao PDR 466 and 413 participants and on Pemba Island, 558 and 515 participants were followed-up six and 12 months post-treatment, respectively. From each participant at least one stool sample was processed for Kato-Katz diagnosis and cure rates (CRs), egg reduction rates (ERRs) and apparent reinfection rates were calculated. If found helminth-positive at six months, participants were re-treated according to their allocated treatment. Long-term outcomes against T. trichiura based on CRs and ERRs of ivermectin-albendazole compared to albendazole were significantly higher at six months in Lao PDR (CR, 65.8 vs 13.4%, difference; 52.4; 95% CI 45.0-60.0; ERRs, 99.0 vs 79.6, difference 19.4; 95% CI 14.4-24.4) and Pemba Island (CR, 17.8 vs 1.4%, difference; 16.4; 95% CI 11.6-21.0; ERRs, 84.9 vs 21.2, difference 63.8; 95% CI 50.6-76.9) and also at 12 months in Lao PDR (CR, 74.0 vs 23.4%, difference; 50.6; 95% CI 42.6-61.0; ERRs, 99.6 vs 91.3, difference 8.3; 95% CI 5.7-10.8) and Pemba Island (CR, 19.5 vs 3.4%, difference; 16.1; 95% CI 10.7-21.5; ERRs, 92.9 vs 53.6, difference 39.3; 95% CI 31.2-47.4) respectively. Apparent reinfection rates with T. trichiura were considerably higher on Pemba Island (100.0%, 95% CI, 29.2-100.0) than in Lao PDR (10.0%, 95% CI, 0.2-44.5) at 12 months post-treatment for participants treated with albendazole alone. CONCLUSIONS/SIGNIFICANCE The long-term outcomes against T. trichiura of ivermectin-albendazole are superior to albendazole in terms of CRs and ERRs and in reducing infection intensities. Our results will help to guide decisions on how to best use ivermectin-albendazole in the context of large-scale PC programs tailored to the local context to sustainably control STH infections. TRIAL REGISTRATION ClinicalTrials.gov registered with clinicaltrials.gov, reference: NCT03527732, date assigned: 17 May 2018.
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Affiliation(s)
- Ladina Keller
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sophie Welsche
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Chandni Patel
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Somphou Sayasone
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Department of International Program for Health in the Tropics, Lao Tropical and Public Health Institute, Vientiane, Lao People’s Democratic Republic
| | - Said M. Ali
- Public Health Laboratory Ivo de Carneri, Chake Chake, Pemba, Zanzibar, Tanzania
| | - Shaali M. Ame
- Public Health Laboratory Ivo de Carneri, Chake Chake, Pemba, Zanzibar, Tanzania
| | - Jan Hattendorf
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Eveline Hürlimann
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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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: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [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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Kamani J, Massetti L, Olubade T, Balami JA, Samdi KM, Traub RJ, Colella V, González-Miguel J. Canine gastrointestinal parasites as a potential source of zoonotic infections in Nigeria: A nationwide survey. Prev Vet Med 2021; 192:105385. [PMID: 34023722 DOI: 10.1016/j.prevetmed.2021.105385] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/24/2021] [Accepted: 05/16/2021] [Indexed: 11/28/2022]
Abstract
Dog feces may contain zoonotic parasites that contaminate the environment and serve as a potential source of infection to animals and humans. In this study, microscopic and molecular analyses were used to estimate the prevalence and intensity of gastrointestinal (GI) parasites and assess the risk factors for infection in 948 dogs in three climatically distinct zones of Nigeria. Zoonotic helminths including Strongyloides stercoralis, Ancylostoma braziliense, A. caninum and Toxocara canis were detected either as single or multiple infections in 377 (39.8 %) of dogs examined. At multiple logistic regression analyses, association was found between GI parasite infection and deworming practices and dog management. Regarding A. braziliense, A. caninum and T. canis infections, intensity of egg shedding was statistically associated with the age of the dogs and not with their sex or breed. The majority of GI parasite-positive dogs did not receive regular deworming treatment (59 %) and roamed freely (56 %) thereby constituting public health risk. This is the first nationwide survey and analyses of risk factors of GI parasites of dogs using molecular methods as confirmation of their identity. The zoonotic potential of these parasites is exacerbated by the lack of both operational national policies to control the population of free-roaming dogs and to promote responsible dog ownership, and veterinary public health programs for dogs.
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Affiliation(s)
- Joshua Kamani
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria.
| | - Luca Massetti
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3052, Australia
| | - Toyin Olubade
- National Veterinary Research Institute (NVRI), PMB 01 Vom, Plateau State, Nigeria
| | | | | | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3052, Australia
| | - Vito Colella
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3052, Australia
| | - Javier González-Miguel
- Laboratory of Parasitology, Institute of Natural Resources and Agrobiology of Salamanca (IRNASA-CSIC), C/ Cordel de Merinas 40-52, 37008, Salamanca, Spain
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Habib A, Andrianonimiadana L, Rakotondrainipiana M, Andriantsalama P, Randriamparany R, Randremanana RV, Rakotoarison R, Vigan-Womas I, Rafalimanantsoa A, Vonaesch P, Sansonetti PJ, Collard JM. High prevalence of intestinal parasite infestations among stunted and control children aged 2 to 5 years old in two neighborhoods of Antananarivo, Madagascar. PLoS Negl Trop Dis 2021; 15:e0009333. [PMID: 33878113 PMCID: PMC8087024 DOI: 10.1371/journal.pntd.0009333] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 04/30/2021] [Accepted: 03/25/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND This study aimed to compare the prevalence of intestinal parasite infestations (IPIs) in stunted children, compared to control children, in Ankasina and Andranomanalina Isotry (two disadvantaged neighborhoods of Antananarivo, Madagascar), to characterize associated risk factors and to compare IPI detection by real-time PCR and standard microscopy techniques. METHODOLOGY/PRINCIPAL FINDINGS Fecal samples were collected from a total of 410 children (171 stunted and 239 control) aged 2-5 years. A single stool sample per subject was examined by simple merthiolate-iodine-formaldehyde (MIF), Kato-Katz smear and real-time PCR techniques. A total of 96.3% of the children were infested with at least one intestinal parasite. The most prevalent parasites were Giardia intestinalis (79.5%), Ascaris lumbricoides (68.3%) and Trichuris trichiura (68.0%). For all parasites studied, real-time PCR showed higher detection rates compared to microscopy (G. intestinalis [77.6% (n = 318) versus 20.9% (n = 86)], Entamoeba histolytica [15.8% (n = 65) versus 1.9% (n = 8)] and A. lumbricoides [64.1% (n = 263) versus 50.7% (n = 208)]). Among the different variables assessed in the study, age of 4 to 5 years (AOR = 4.61; 95% CI, (1.35-15.77)) and primary and secondary educational level of the mother (AOR = 12.59; 95% CI, (2.76-57.47); AOR = 9.17; 95% CI, (2.12-39.71), respectively) were significantly associated with IPIs. Children drinking untreated water was associated with infestation with G. intestinalis (AOR = 1.85; 95% CI, (1.1-3.09)) and E. histolytica (AOR = 1.9; 95% CI, (1.07-3.38)). E. histolytica was also associated with moderately stunted children (AOR = 0.37; 95% CI, 0.2-0.71). Similarly, children aged between 4 and 5 years (AOR = 3.2; 95% CI (2.04-5.01)) and living on noncemented soil types (AOR = 1.85; 95% CI, (1.18-2.09)) were associated with T. trichiura infestation. CONCLUSIONS/SIGNIFICANCE The prevalence of IPIs is substantial in the studied areas in both stunted and control children, despite the large-scale drug administration of antiparasitic drugs in the country. This high prevalence of IPIs warrants further investigation. Improved health education, environmental sanitation and quality of water sources should be provided.
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Affiliation(s)
- Azimdine Habib
- Unité de Bactériologie Expérimentale, Institut Pasteur de Madagascar, Antananarivo, Madagascar
- * E-mail:
| | - Lova Andrianonimiadana
- Unité de Bactériologie Expérimentale, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | | | - Prisca Andriantsalama
- Unité d’Epidémiologie et de Recherche Clinique, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Ravaka Randriamparany
- Unité d’Epidémiologie et de Recherche Clinique, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | | | - Rado Rakotoarison
- Unité d’Immunologie des Maladies Infectieuses, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Inès Vigan-Womas
- Unité d’Immunologie des Maladies Infectieuses, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | | | - Pascale Vonaesch
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur Paris, France
| | | | - Jean-Marc Collard
- Unité de Bactériologie Expérimentale, Institut Pasteur de Madagascar, Antananarivo, Madagascar
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Iron homeostasis during anemia of inflammation: a prospective study in patients with tuberculosis. Blood 2021; 138:1293-1303. [PMID: 33876222 DOI: 10.1182/blood.2020010562] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 04/02/2021] [Indexed: 11/20/2022] Open
Abstract
Anemia of inflammation is a hallmark of tuberculosis. Factors controlling iron metabolism during anemia of inflammation and its resolution are uncertain. Whether iron supplements should be given during anti-tuberculosis treatment to support Hb recovery is unclear. Before and during treatment of tuberculosis, we assessed iron kinetics, and changes in inflammation and iron metabolism indices. In a 26-wk prospective study, Tanzanian adults with tuberculosis (n=18) were studied before treatment and then every two weeks during treatment; oral and intravenous iron tracers were administered before treatment, after intensive phase (8/12 wk) and complete treatment (24 wk); no iron supplements were given. Before treatment, hepcidin and erythroferrone (ERFE) were greatly elevated, erythrocyte iron utilization was high (~80%) and iron absorption was negligible (<1%). During treatment, hepcidin and IL-6 decreased ~70% after only 2 wk (p<0.001); in contrast, ERFE did not significantly decrease until 8 wk (p<0.01). ERFE and IL-6 were the main opposing determinants of hepcidin (p<0.05) and greater ERFE was associated with reticulocytosis and hemoglobin (Hb) repletion (p<0.01). Dilution of baseline tracer concentration was 2.6-fold higher during intensive phase treatment (p<0.01) indicating enhanced erythropoiesis. After treatment completion, iron absorption increased ~20-fold (p<0.001); Hb increased ~25% (p<0.001). In tuberculosis-associated anemia of inflammation, our findings suggest elevated ERFE is unable to suppress hepcidin and iron absorption is negligible. During treatment, as inflammation resolves, ERFE may remain elevated, contributing to hepcidin suppression and Hb repletion. Iron is well-absorbed only after tuberculosis treatment and supplementation should be reserved for patients remaining anemic after treatment. (ClinicalTrials.gov Identifier:NCT02176772).
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Eltantawy M, Orsel K, Schroeder A, Morona D, Mazigo HD, Kutz S, Hatfield J, Manyama M, van der Meer F. Soil transmitted helminth infection in primary school children varies with ecozone in the Ngorongoro Conservation Area, Tanzania. Trop Med Health 2021; 49:22. [PMID: 33691800 PMCID: PMC7945338 DOI: 10.1186/s41182-021-00310-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/22/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Soil-transmitted helminthiasis is a neglected tropical disease, thriving in environments of poverty and disadvantage. Our objective was to determine the prevalence and intensity of four soil transmitted helminths (STH) among primary school children in the Ngorongoro Conservation Area (NCA), Tanzania. METHODS A cross-sectional study was performed between May 15th and June 2nd, 2014. Six of 20 primary schools were chosen, based on elevation, designated low elevation ecozone (LEE) or high elevation ecozone (HEE). A total of 340 children from standards one to four were recruited. Height and weight of each child was determined and body mass index (BMI) was calculated. Stool samples were analyzed using the Kato-Katz, Wisconsin, and Baermann techniques to detect STH eggs and larvae. An interviewer-administered questionnaire on socio-demographic variables was used to capture information from the school's headmaster and a checklist was used to assess sanitation facilities. RESULTS STHs identified included Ascaris (presumably lumbricoides), Trichuris (presumably trichiura), hookworms (presumably Ancylostoma duodenale and/or Necator americanus), and Strongyloides (presumably stercoralis). The overall prevalence of STH infection was 29.0% in LEE and 34.0% in HEE. Prevalence was 34.3% and 28.2% in males versus females, respectively. Ascaris sp. were only identified in HEE, prevalence of Trichuris sp. and hookworms were significantly higher in HEE compared to LEE, and Strongyloides spp. prevalence was lower in HEE. Intensity of Trichuris sp. was significantly higher in HEE and lower for hookworms. We did not detect a significant relationship between BMI and helminth intensity; however, BMI was lower in lower elevations and in males vs. females. Sanitation practices are taught at the schools, but challenges were identified when implementing. Latrine facilities were available and latrine-cleaning routines were practiced; however, hand washing practices were challenging due to restricted water availability. CONCLUSIONS Significant differences in prevalence in HEE and LEE exist, and STH infections are still very common among school children suggesting that anthelminthic intervention and education may be necessary in this region. Based on this outcome, the study area in the NCA would be classified as a medium risk area, where periodic treatment recommendations should be based on prevalence estimations in the different ecozones. TRIAL REGISTRATION Ethics approval was obtained from the Catholic University of Health and Allied Sciences (CUHAS; Lake Zone Institutional Review Board MR/53/100/307)); the Conjoint Health Research Ethics Board (CHREB) at the University of Calgary in Canada (Study ID REB14-0127); the National Institute of Medical Research (NIMR) of Tanzania; and the Tanzania Commission for Science and Technology (COSTEC).
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Affiliation(s)
- Manar Eltantawy
- Department. of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Karin Orsel
- Department. of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ashley Schroeder
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Domenica Morona
- Department of Parasitology, Catholic University of Health and Allied Science, Mwanza, Tanzania
| | - Humphrey D Mazigo
- Department of Parasitology, Catholic University of Health and Allied Science, Mwanza, Tanzania
| | - Susan Kutz
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Jennifer Hatfield
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Mange Manyama
- Division of Medical Education, Weill Cornell Medicine - Qatar, Doha, Qatar
| | - Frank van der Meer
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.
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Gordon CA, Shield JM, Bradbury RS, Muhi S, Page W, Judd JA, Lee R, Biggs BA, Ross K, Kurscheid J, Gray DJ, McManus DP. HTLV-I and Strongyloides in Australia: The worm lurking beneath. ADVANCES IN PARASITOLOGY 2021; 111:119-201. [PMID: 33482974 DOI: 10.1016/bs.apar.2020.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Strongyloidiasis and HTLV-I (human T-lymphotropic virus-1) are important infections that are endemic in many countries around the world with an estimated 370 million infected with Strongyloides stercoralis alone, and 5-10 million with HTVL-I. Co-infections with these pathogens are associated with significant morbidity and can be fatal. HTLV-I infects T-cells thus causing dysregulation of the immune system which has been linked to dissemination and hyperinfection of S. stercoralis leading to bacterial sepsis which can result in death. Both of these pathogens are endemic in Australia primarily in remote communities in Queensland, the Northern Territory, and Western Australia. Other cases in Australia have occurred in immigrants and refugees, returned travellers, and Australian Defence Force personnel. HTLV-I infection is lifelong with no known cure. Strongyloidiasis is a long-term chronic disease that can remain latent for decades, as shown by infections diagnosed in prisoners of war from World War II and the Vietnam War testing positive decades after they returned from these conflicts. This review aims to shed light on concomitant infections of HTLV-I with S. stercoralis primarily in Australia but in the global context as well.
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Affiliation(s)
- Catherine A Gordon
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| | - Jennifer M Shield
- Department of Pharmacy and Biomedical Sciences, La Trobe University, Bendigo, VIC, Australia; Department of Medicine, The Peter Doherty Institute for Infection and Immunity, University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Richard S Bradbury
- School of Health and Life Sciences, Federation University, Berwick, VIC, Australia
| | - Stephen Muhi
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Wendy Page
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Jenni A Judd
- School of Health Medical and Applied Sciences, Central Queensland University, Bundaberg, QLD, Australia; Centre for Indigenous Health Equity Research, Central Queensland University, Bundaberg, QLD, Australia
| | - Rogan Lee
- Westmead Clinical School, The University of Sydney, Westmead, NSW, Australia
| | - Beverley-Ann Biggs
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia; Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Kirstin Ross
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Johanna Kurscheid
- Department of Global Health, Research School of Population Health, Australian National University, Acton, ACT, Australia
| | - Darren J Gray
- Department of Global Health, Research School of Population Health, Australian National University, Acton, ACT, Australia
| | - Donald P McManus
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
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Helminth infections among rural schoolchildren in Southern Ethiopia: A cross-sectional multilevel and zero-inflated regression model. PLoS Negl Trop Dis 2020; 14:e0008002. [PMID: 33351816 PMCID: PMC7755205 DOI: 10.1371/journal.pntd.0008002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 10/20/2020] [Indexed: 11/19/2022] Open
Abstract
Although the prevalence of helminths infection among schoolchildren is known, there has been little progress in the application of count model for modelling the risk factors of helminths egg. Only a few studies applied multilevel analysis to explore the variation in helminths prevalence across schools and classes. This study aimed to assess the prevalence, intensity of helminths infection, and identify risk factors at the individual-, household-, and school-level among schoolchildren in Southern Ethiopia. Using multistage random sampling, we recruited 864 students in the Wonago District. We applied multilevel-logistic and zero-inflated negative binomial regression models (ZINB). Risk factors were concentrated at the individual level; school-level and class-level variables explained less than 5% of the variance. The overall helminths prevalence was 56% (479/850); Trichuris trichiura prevalence was 42.4% (360/850); and Ascaris lumbricoides prevalence was 18.7% (159/850). The rate of any helminths increased among thin children (AOR: 1.73 [95% CI: (1.04, 2.90]), anemic (AOR: 1.45 [95% CI: 1.04, 2.03]), mothers who had no formal education (AOR: 2.08 [95% CI: 1.25, 3.47]), and those in households using open containers for water storage (AOR: 2.06 [95% CI: 1.07, 3.99]). In the ZINB model, A. lumbricoides infection intensity increased with increasing age (AOR: 1.08 [95% CI: 1.01, 1.16]) and unclean fingernails (AOR: 1.47 [95% CI: 1.07, 2.03]). Handwashing with soap (AOR: 0.68 [95% CI: 0.48, 0.95]), de-worming treatment [AOR: 0.57 (95% CI: 0.33, 0.98)], and using water from protected sources [AOR: 0.46 (95% CI: 0.28, 0.77)] were found to be protective against helminths infection. After controlling for clustering effects at the school and class levels and accounting for excess zeros in fecal egg counts, we found an association between helminths infection and the following variables: age, thinness, anemia, unclean fingernails, handwashing, de-worming treatment, mother's education, household water source, and water storage protection. Improving hygiene behavior, providing safe water at school and home, and strengthening de-worming programs is required to improve the health of schoolchildren in rural Gedeo.
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Farrant O, Marlais T, Houghton J, Goncalves A, Teixeira da Silva Cassama E, Cabral MG, Nakutum J, Manjuba C, Rodrigues A, Mabey D, Bailey R, Last A. Prevalence, risk factors and health consequences of soil-transmitted helminth infection on the Bijagos Islands, Guinea Bissau: A community-wide cross-sectional study. PLoS Negl Trop Dis 2020; 14:e0008938. [PMID: 33326420 PMCID: PMC7773412 DOI: 10.1371/journal.pntd.0008938] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/30/2020] [Accepted: 10/30/2020] [Indexed: 11/19/2022] Open
Abstract
Soil-transmitted helminths (STH) are endemic and widespread across Sub-Saharan Africa. A community wide soil-transmitted helminth (STH) prevalence survey was performed on the island of Bubaque in Guinea-Bissau using both Kato-katz microscopy and qPCR methodology. Predictors of infection and morbidity indicators were identified using multivariable logistic regression, and diagnostic methods were compared using k statistics. Among 396 participants, prevalence of STH by microscopy was 23.2%, hookworm was the only species identified by this method and the mean infection intensity was 312 eggs per gram. qPCR analysis revealed an overall prevalence of any STH infection of 47.3%, with the majority A. duodenale (32.3%), followed by N. americanus (15.01%) and S. stercoralis (13.2%). A. lumbricoides, and T. trichiura infections were negligible, with a prevalence of 0.25% each. Agreement between diagnostic tests was k = 0.22, interpreted as fair agreement, and infection intensity measured by both methods was only minimally correlated (Rs = -0.03). STH infection overall was more common in females and adults aged 31-40. STH infection was associated with open defaecation, low socio-economic status and further distance to a water-source. The prevalence of anaemia (defined as a binary outcome by the WHO standards for age and sex) was 69.1%, and 44.2% of children were malnourished according to WHO child growth standards. Hookworm infection intensity by faecal egg count showed no statistically significant association with age (Rs 0.06) but S. Stercoralis infection intensity by qPCR cycle threshold was higher in pre-school aged children (Rs = 0.30, p-value 0.03) There was no statistically significant association between STH infection and anaemia (OR 1.0 p = 0.8), stunting (OR 1.9, p-value 0.5) and wasting (OR 2.0, p-value 0.2) in children. This study reveals a persistent reservoir of STH infection across the community, with high rates of anaemia and malnutrition, despite high-coverage of mebendazole mass-drug administration in pre-school children. This reflects the need for a new strategy to soil-transmitted helminth control, to reduce infections and ultimately eliminate transmission.
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Affiliation(s)
- Olivia Farrant
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Tegwen Marlais
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Joanna Houghton
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Adriana Goncalves
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | | | - Jose Nakutum
- Region Sanitaria Bolama-Bijagós, Bubaque, Guinea Bissau
| | | | | | - David Mabey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Robin Bailey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Anna Last
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Hailu T, Nibret E, Amor A, Munshea A. Strongyloidiasis in Africa: Systematic Review and Meta-Analysis on Prevalence, Diagnostic Methods, and Study Settings. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2868564. [PMID: 33274200 PMCID: PMC7683116 DOI: 10.1155/2020/2868564] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 11/01/2020] [Accepted: 11/04/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Strongyloidiasis is an intestinal parasitic infection mainly caused by Strongyloides stercoralis. Although it is a predominant parasite in tropics and subtropics where sanitation and hygiene are poorly practiced, the true prevalence of strongyloidiasis is not known due to low-sensitivity diagnostic methods. OBJECTIVE This systematic review and meta-analysis is aimed at determining the pooled prevalence of strongyloidiasis in African countries, stratified by diagnostic methods, study settings, and patients. METHODS Cross-sectional studies on strongyloidiasis published in African countries from the year 2008 up to 2018 in PubMed and Google Scholar databases and which reported at least one Strongyloides spp. infection were included. Identification and screening of eligible articles were also done. Articles whose focus was on strongyloidiasis in animals, soil, and foreigners infected by Strongyloides spp. in Africa were excluded. The random effects model was used to calculate the pooled prevalence of strongyloidiasis across African countries as well as by diagnostic methods and study settings. The heterogeneity between studies was also computed. RESULT A total of 82 studies were included. The overall pooled prevalence of strongyloidiasis was 2.7%. By individual techniques, the pooled prevalence of strongyloidiasis was 0.4%, 1.0%, 3.4%, 9.3%, 9.6%, and 19.4% by the respective direct saline microscopy, Kato-Katz, formol ether concentration, polymerase chain reaction, Baermann concentration, and culture diagnostic techniques. The prevalence rates of strongyloidiasis among rural community, school, and health institution studies were 6.8%, 6.4%, and 0.9%, respectively. The variation on the effect size comparing African countries, diagnostic methods, study settings, and patients was significant (P ≤ 0.001). CONCLUSIONS This review shows that strongyloidiasis is overlooked and its prevalence is estimated to be low in Africa due to the use of diagnostic methods with low sensitivity. Therefore, there is a need for using a combination of appropriate diagnostic methods to approach the actual strongyloidiasis rates in Africa.
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Affiliation(s)
- Tadesse Hailu
- College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar City, Ethiopia P.O. Box 79
| | - Endalkachew Nibret
- Biology Department, Science College, Bahir Dar University, Bahir Dar City, Ethiopia P.O. Box 79
| | | | - Abaineh Munshea
- Biology Department, Science College, Bahir Dar University, Bahir Dar City, Ethiopia P.O. Box 79
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Wong LW, Ong KS, Khoo JR, Goh CBS, Hor JW, Lee SM. Human intestinal parasitic infection: a narrative review on global prevalence and epidemiological insights on preventive, therapeutic and diagnostic strategies for future perspectives. Expert Rev Gastroenterol Hepatol 2020; 14:1093-1105. [PMID: 32755242 DOI: 10.1080/17474124.2020.1806711] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Intestinal parasitic infection (IPI) is a global health concern among socioeconomically deprived communities in many developing countries. Many preventative strategies have been deployed to control IPI, however, there is a lack in standards on the techniques used to diagnose and monitor the prevalence of IPI. AREAS COVERED The present article will review the diseases associated with IPI and discuss the current IPI control strategies such as the water, sanitation, and hygiene (WASH) interventions, community-led total sanitation (CLTS) approach, and regular anthelminthic treatments. For the first time, this review will also evaluate all currently practised diagnostic techniques for the detection of intestinal parasites and provide insights on future IPI control strategies. EXPERT OPINION Advanced and improved diagnostic methods such as qPCR coupled with a high-resolution melting curve, aptamers, biosensors, and detection of extracellular vesicles can be used for detection of IPI. Vaccination against intestinal parasites can be made available to increase antibodies to interfere with the blood-feeding process by the parasites, which subsequently reduces the reproductive rates of the parasites. These methods collectively can serve as future management strategies for intestinal parasitic infections.
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Affiliation(s)
- Li Wen Wong
- School of Science, Monash University Malaysia , Bandar Sunway, Malaysia
| | - Kuan Shion Ong
- School of Science, Monash University Malaysia , Bandar Sunway, Malaysia.,Tropical Medicine and Biology Multidisciplinary Platform, Monash University Malaysia , Bandar Sunway, Malaysia
| | - Jun Rong Khoo
- School of Science, Monash University Malaysia , Bandar Sunway, Malaysia
| | - Calvin Bok Sun Goh
- School of Science, Monash University Malaysia , Bandar Sunway, Malaysia.,Tropical Medicine and Biology Multidisciplinary Platform, Monash University Malaysia , Bandar Sunway, Malaysia
| | - Jia Wei Hor
- Department of Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| | - Sui Mae Lee
- School of Science, Monash University Malaysia , Bandar Sunway, Malaysia.,Tropical Medicine and Biology Multidisciplinary Platform, Monash University Malaysia , Bandar Sunway, Malaysia
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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] [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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Barda B, Schindler C, Wampfler R, Ame S, Ali SM, Keiser J. Comparison of real-time PCR and the Kato-Katz method for the diagnosis of soil-transmitted helminthiasis and assessment of cure in a randomized controlled trial. BMC Microbiol 2020; 20:298. [PMID: 33008301 PMCID: PMC7531123 DOI: 10.1186/s12866-020-01963-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/01/2020] [Indexed: 02/05/2023] Open
Abstract
Background Diagnosis of soil-transmitted helminths (STHs) in developing countries is commonly based on microscopic detection of eggs in stool samples, using the Kato-Katz (KK) method, which has a poor sensitivity for detecting light intensity infections. We compared the performance of the KK method and real-time PCR in the framework of a randomized trial, which evaluated four novel treatments against Trichuris trichiura and concomitant STH infections. Results Two stool samples obtained from 320 participants were examined at baseline and follow-up with quadruplicate KK and PCR analyses of one of the two samples using “bead-beating” for DNA extraction. At follow-up, 80 samples were negative according to both PCR and KK and 173 were positive with both methods for any of the STHs. Relative to PCR, the calculated sensitivity of KK at follow-up was 83.6%, 43.0% and 53.8% for T. trichiura, for hookworm and for Ascaris lumbricoides, respectively. The sensitivity of PCR compared with KK at this time point was 89.1% for T. trichiura, 72.7% for hookworm and 87.5% for A. lumbricoides. Cure rates (CRs) for T. trichiura and A. lumbricoides were slightly lower with the PCR method. For hookworm CRs with KK were mostly significantly lower, namely 36.7%, 91.1%, 72.2% and 77.8% for moxidectin, moxidectin in combination with tribendimidine, moxidectin in combination with albendazole and albendazole in combination with oxantel pamoate, respectively, whereas with PCR the CRs were 8.3%, 82.6%, 37.1% and 57.1%, respectively. Conclusions In conclusion, a single real-time PCR is as sensitive as quadruplicate KK for T. trichiura and A. lumbricoides detection but more sensitive for hookworm, which has an influence on the estimated treatment efficacy. PCR method with DNA extraction using the “bead-beating protocol” should be further promoted in endemic areas and laboratories that can afford the needed equipment. The study is registered at ISRCTN (no. 20398469).
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Affiliation(s)
- Beatrice Barda
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Christian Schindler
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Rahel Wampfler
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Shaali Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake-Chake, Tanzania
| | - Said M Ali
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake-Chake, Tanzania
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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Kridaningsih TN, Sukmana DJ, Mufidah H, Diptyanusa A, Kusumasari RA, Burdam FH, Kenangalem E, Poespoprodjo JR, Fuad A, Mahendradhata Y, Supargiyono S, Utzinger J, Becker SL, Murhandarwati EEH. Epidemiology and risk factors of Strongyloides stercoralis infection in Papua, Indonesia: a molecular diagnostic study. Acta Trop 2020; 209:105575. [PMID: 32505594 DOI: 10.1016/j.actatropica.2020.105575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/19/2020] [Accepted: 06/02/2020] [Indexed: 10/24/2022]
Abstract
Strongyloides stercoralis is a parasitic worm that is of considerable clinical relevance. Indeed, it may persist asymptomatically for many years, but can lead to potentially fatal dissemination when the host's immune status is impaired. As commonly employed stool microscopy techniques (e.g. Kato-Katz thick smear) fail to detect S. stercoralis, the epidemiology is poorly understood. In 2013, we conducted a cross-sectional household survey in the district of Mimika in Papua, Indonesia. A total of 331 individuals, aged 1 month to 44 years, had a single stool sample subjected to real-time polymerase chain reaction (PCR) for S. stercoralis diagnosis. The prevalence of S. stercoralis infection was 32.0% (106/331 individuals); higher than any of the three main soil-transmitted helminths (Ascaris lumbricoides, 23.9%; Trichuris trichiura, 18.4%; and hookworm, 17.2%). Amongst the S. stercoralis-infected individuals, 73.6% were concurrently infected with another helminth, with hookworm being the most frequent co-infection (27.4%). Fourteen percent of the S. stercoralis infections had low cycle threshold values on real-time PCR, which may indicate a higher infection intensity. Multivariate logistic regression analysis revealed that age ≥5 years (adjusted odds ratio (OR) 5.8, 95% confidence interval (CI): 3.1-10.8) was significantly associated with S. stercoralis infection. There is a need for in-depth clinical and diagnostic studies to elucidate the public health impact of S. stercoralis infection in Indonesia.
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Adisakwattana P, Yoonuan T, Phuphisut O, Poodeepiyasawat A, Homsuwan N, Gordon CA, McManus DP, Atkinson LE, Mousley A, Gobert GN. Clinical helminthiases in Thailand border regions show elevated prevalence levels using qPCR diagnostics combined with traditional microscopic methods. Parasit Vectors 2020; 13:416. [PMID: 32787935 PMCID: PMC7425172 DOI: 10.1186/s13071-020-04290-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/05/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Under-regulated national borders in Southeast Asia represent potential regions for enhanced parasitic helminth transmission and present barriers to helminthiasis disease control. METHODS Three Thailand border regions close to Myanmar, Laos and Cambodia were surveyed for clinical parasitic helminth disease. In-field microscopy was performed on stools from 567 individuals. Sub-samples were transported to Bangkok for molecular analysis comprising three multiplex qPCR assays. RESULTS The overall helminth infection prevalence was 17.99% as assessed by Kato-Katz and 24.51% by qPCR. The combined prevalence of the two methods was 28.57%; the most predominant species detected were Opisthorchis viverrini (18.34%), hookworm (6.88%; Ancylostoma spp. and Necator americanus), Ascaris lumbricoides (2.29%) and Trichuris trichiura (1.76%). CONCLUSIONS These data demonstrate the value of molecular diagnostics for determining more precise prevalence levels of helminthiases in Southeast Asia. Availability of such accurate prevalence information will help guide future public health initiatives and highlights the need for more rigorous surveillance and timely intervention in these regions.
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Affiliation(s)
- Poom Adisakwattana
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| | - Tippayarat Yoonuan
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Orawan Phuphisut
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Akkarin Poodeepiyasawat
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Nirundorn Homsuwan
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Louise E Atkinson
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Angela Mousley
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Geoffrey N Gobert
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK.
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Balachandra D, Ahmad H, Arifin N, Noordin R. Direct detection of Strongyloides infection via molecular and antigen detection methods. Eur J Clin Microbiol Infect Dis 2020; 40:27-37. [DOI: 10.1007/s10096-020-03949-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/09/2020] [Indexed: 12/16/2022]
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Soares FA, Benitez ADN, dos Santos BM, Loiola SHN, Rosa SL, Nagata WB, Inácio SV, Suzuki CTN, Bresciani KDS, Falcão AX, Gomes JF. A historical review of the techniques of recovery of parasites for their detection in human stools. Rev Soc Bras Med Trop 2020; 53:e20190535. [PMID: 32491097 PMCID: PMC7269538 DOI: 10.1590/0037-8682-0535-2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/30/2020] [Indexed: 11/22/2022] Open
Abstract
Since the early 20th century, the detection of intestinal parasites has improved with the development of several techniques for parasitic structures recovery and identification, which differ in sensitivity, specificity, practicality, cost, and infrastructure demand. This study aims to review, in chronological order, the stool examination techniques and discuss their advantages, limitations, and perspectives, and to provide professionals and specialists in this field with data that lays a foundation for critical analysis on the use of such procedures. The concentration procedures that constitute the main techniques applied in routine research and in parasitological kits are a) spontaneous sedimentation; b) centrifugation-sedimentation with formalin-ethyl acetate; and c) flotation with zinc sulfate solution. While selecting a technique, one should consider the purpose of its application and the technical-operational, biological, and physicochemical factors inherent in the procedures used in stool processing, which may restrict its use. These intrinsic limitations may have undergone procedural changes driven by scientific and technological development and by development of alternative methods, which now contribute to the improvement of diagnostic accuracy.
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Affiliation(s)
- Felipe Augusto Soares
- Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Campinas, SP, Brasil
| | | | | | | | - Stefany Laryssa Rosa
- Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Campinas, SP, Brasil
| | - Walter Bertequini Nagata
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária, Departamento de Apoio, Produção e Saúde Animal, Araçatuba, SP, Brasil
| | - Sandra Valéria Inácio
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária, Departamento de Apoio, Produção e Saúde Animal, Araçatuba, SP, Brasil
| | | | - Katia Denise Saraiva Bresciani
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária, Departamento de Apoio, Produção e Saúde Animal, Araçatuba, SP, Brasil
| | | | - Jancarlo Ferreira Gomes
- Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Campinas, SP, Brasil
- Universidade Estadual de Campinas, Instituto de Computação, Campinas, SP, Brasil
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50
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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] [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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