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Jebiwott S, Gutapaka N, Sumari D, Loss G, Athuman T, Nyandele JP, Cummins H, Chemba M, Benjamin-Chung J, Gangar P, Wu X, Smith J, Chen I, Dorsey G, Fink G, Olotu A, Hsiang M. Child Health and Infection with Low Density (CHILD) malaria: a protocol for a randomised controlled trial to assess the long-term health and socioeconomic impacts of testing and treating low-density malaria infection among children in Tanzania. BMJ Open 2024; 14:e082227. [PMID: 38538037 PMCID: PMC10982758 DOI: 10.1136/bmjopen-2023-082227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/15/2024] [Indexed: 04/04/2024] Open
Abstract
INTRODUCTION As malaria declines, low-density malaria infections (LMIs) represent an increasing proportion of infections and may have negative impacts on child health and cognition, necessitating development of targeted and effective solutions. This trial assesses the health, cognitive and socioeconomic impact of two strategies for detecting and treating LMI in a low transmission setting. METHODS AND ANALYSIS The study is a 3-arm open-label individually randomised controlled trial enrolling 600 children aged 6 months to 10 years in Bagamoyo district, Tanzania. Children are randomised to one of three arms: active case detection with molecular (ACDm) testing by high volume quantitative PCR (qPCR), passive case detection also with molecular testing (PCDm) and a control of standard PCD using rapid diagnostics tests (RDTs). Over the 2-year trial, ACDm participants receive malaria testing using RDT and qPCR three times annually, and malaria testing by RDT only when presenting with fever. PCDm and PCD participants receive malaria testing by RDT and qPCR or RDT only, respectively, when presenting with fever. RDT or qPCR positive participants with uncomplicated malaria are treated with artemether lumefantrine. The primary outcome is cumulative incidence of all-cause sick visits. Secondary outcomes include fever episodes, clinical failure after fever episodes, adverse events, malaria, non-malarial infection, antibiotic use, anaemia, growth faltering, cognition and attention, school outcomes, immune responses, and socioeconomic effects. Outcomes are assessed through monthly clinical assessments and testing, and baseline and endline neurodevelopmental testing. The trial is expected to provide key evidence and inform policy on health, cognitive and socioeconomic impact of interventions targeting LMI in children. ETHICS AND DISSEMINATION Study is approved by Tanzania NatHREC and institutional review boards at University of California San Francisco and Ifakara Health Institute. Findings will be reported on ClinicalTrials.gov, in peer-reviewed journals and through stakeholder meetings. TRIAL REGISTRATION NUMBER NCT05567016.
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Affiliation(s)
- Sylvia Jebiwott
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
| | | | - Deborah Sumari
- Ifakara Health Institute, Bagamoyo, Tanzania, United Republic of
| | - Georg Loss
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Thabit Athuman
- Ifakara Health Institute, Bagamoyo, Tanzania, United Republic of
| | | | - Hannah Cummins
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Mwajuma Chemba
- Ifakara Health Institute, Bagamoyo, Tanzania, United Republic of
| | - Jade Benjamin-Chung
- Epidemiology and Population Health, Stanford University School of Medicine, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - Pamela Gangar
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Xue Wu
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Jennifer Smith
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Ingrid Chen
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Günther Fink
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ally Olotu
- Ifakara Health Institute, Bagamoyo, Tanzania, United Republic of
| | - Michelle Hsiang
- Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, San Francisco, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, USA
- Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA
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Bisanzio D, Lalji S, Abbas FB, Ali MH, Hassan W, Mkali HR, Al-Mafazy AW, Joseph JJ, Nyinondi S, Kitojo C, Serbantez N, Reaves E, Eckert E, Ngondi JM, Reithinger R. Spatiotemporal dynamics of malaria in Zanzibar, 2015-2020. BMJ Glob Health 2023; 8:bmjgh-2022-009566. [PMID: 36639160 PMCID: PMC9843203 DOI: 10.1136/bmjgh-2022-009566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 12/21/2022] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Despite high coverage of malaria interventions, malaria elimination in Zanzibar remains elusive, with the annual number of cases increasing gradually over the last 3 years. OBJECTIVE The aims of the study were to (1) assess the spatiotemporal dynamics of malaria in Zanzibar between 2015 and 2020 and (2) identify malaria hotspots that would allow Zanzibar to develop an epidemiological stratification for more effective and granular intervention targeting. METHODS In this study, we analysed data routinely collected by Zanzibar's Malaria Case Notification (MCN) system. The system collects sociodemographic and epidemiological data from all malaria cases. Cases are passively detected at health facilities (ie, primary index cases) and through case follow-up and reactive case detection (ie, secondary cases). Analyses were performed to identify the spatial heterogeneity of case reporting at shehia (ward) level during transmission seasons. RESULTS From 1 January 2015 to 30 April 2020, the MCN system reported 22 686 index cases. Number of cases reported showed a declining trends from 2015 to 2016, followed by an increase from 2017 to 2020. More than 40% of cases had a travel history outside Zanzibar in the month prior to testing positive for malaria. The proportion of followed up index cases was approximately 70% for all years. Out of 387 shehias, 79 (20.4%) were identified as malaria hotspots in any given year; these hotspots reported 52% of all index cases during the study period. Of the 79 hotspot shehias, 12 were hotspots in more than 4 years, that is, considered temporally stable, reporting 14.5% of all index cases. CONCLUSIONS Our findings confirm that the scale-up of malaria interventions has greatly reduced malaria transmission in Zanzibar since 2006. Analyses identified hotspots, some of which were stable across multiple years. Malaria efforts should progress from a universal intervention coverage approach to an approach that is more tailored to a select number of hotspot shehias.
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Affiliation(s)
- Donal Bisanzio
- RTI International, Washington, District of Columbia, USA
| | - Shabbir Lalji
- RTI International, Dar es Salaam, United Republic of Tanzania
| | - Faiza B Abbas
- Zanzibar Malaria Elimination Programme, Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | - Mohamed H Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | - Wahida Hassan
- Zanzibar Malaria Elimination Programme, Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | | | | | - Joseph J Joseph
- RTI International, Dar es Salaam, United Republic of Tanzania
| | - Ssanyu Nyinondi
- RTI International, Dar es Salaam, United Republic of Tanzania
| | - Chonge Kitojo
- U.S. President’s Malaria Initiative, U.S. Agency for International Development, Dar es Salaam, United Republic of Tanzania
| | - Naomi Serbantez
- U.S. President’s Malaria Initiative, U.S. Agency for International Development, Dar es Salaam, United Republic of Tanzania
| | - Erik Reaves
- U.S. President’s Malaria Initiative, U.S. Centers for Disease Control, Dar es Salaam, United Republic of Tanzania
| | - Erin Eckert
- RTI International, Washington, District of Columbia, USA
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Awosolu OB, Yahaya ZS, Farah Haziqah MT, Olusi TA. Performance Evaluation of Nested Polymerase Chain Reaction (Nested PCR), Light Microscopy, and Plasmodium falciparum Histidine-Rich Protein 2 Rapid Diagnostic Test (PfHRP2 RDT) in the Detection of Falciparum Malaria in a High-Transmission Setting in Southwestern Nigeria. Pathogens 2022; 11:1312. [PMID: 36365063 PMCID: PMC9694681 DOI: 10.3390/pathogens11111312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 09/16/2023] Open
Abstract
Malaria remains a major public health challenge worldwide. In order to ensure a prompt and accurate malaria diagnosis, the World Health Organization recommended the confirmatory parasitological diagnosis of malaria by microscopy and malaria rapid diagnostic test (RDT) prior to antimalarial administration and treatment. This study was designed to evaluate the performance of nested polymerase chain reaction (nested PCR), light microscopy, and Plasmodium falciparum histidine-rich protein 2 rapid diagnostic test (PfHRP2 RDT) in the detection of falciparum malaria in Akure, Nigeria. A cross-sectional and hospital-based study involving 601 febrile volunteer participants was conducted in Akure, Nigeria. Approximately 2-3 mL venous blood samples were obtained from each study participant for parasitological confirmation by microscopy and PfHRP2-based malaria RDT. Thick and thin films were prepared and viewed under the light microscope for parasite detection, parasite density quantification, and species identification, respectively. Dry blood spot samples were prepared on 3MM Whatman filter paper for nested PCR. The overall prevalence of microscopy, PfHRP2 RDT, and nested PCR were 64.89% (390/601), 65.7% (395/601), and 67.39% (405/601), respectively. The estimates of sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and Youden's j index of microscopy and RDT were 96.30, 100.00, 100.00, 92.89, 97.50, 0.963, and 95.06, 94.90, 97.47, 90.29, 95.01, and 0.899, respectively. Malaria RDT recorded higher false negativity, compared microscopy (4.94% vs. 3.70%). A near perfect agreement was reported between microscopy and nested PCR, and between PfHRP2 RDT and nested PCR with Cohen's kappa (k) values of 0.94 and 0.88, respectively. This study revealed that PfHRP2 RDT and microscopy continues to remain sensitive and specific for falciparum malaria diagnosis in the study area.
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Affiliation(s)
- Oluwaseun Bunmi Awosolu
- School of Biological Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia
- Vector Control Research Unit, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia
- Department of Biology, Federal University of Technology, Akure 340252, Nigeria
| | - Zary Shariman Yahaya
- School of Biological Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia
- Vector Control Research Unit, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia
| | | | - Titus Adeniyi Olusi
- Vector Control Research Unit, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia
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Lin K, Li M, Wang D, Luo F, Lu S, Michael MG, Mlacha Y, Chaki P, Xiao N, Zhou XN. Evaluation of Malaria Standard Microscopy and Rapid Diagnostic Tests for Screening - Southern Tanzania, 2018-2019. China CDC Wkly 2022; 4:605-608. [PMID: 35919478 PMCID: PMC9339368 DOI: 10.46234/ccdcw2022.132] [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: 03/30/2022] [Accepted: 07/08/2022] [Indexed: 11/14/2022] Open
Abstract
What is already known about this topic? Microscopy is the gold standard for parasitological confirmation, but the accuracy of microscopic diagnosis is influenced by the skill of the technicians. An alternative is the immunologic-based malaria rapid diagnostic tests (mRDTs). What is added by this report? Our study evaluated standard microscopy in health system (SMHS) and mRDTs for focused screening and treatment of malaria (FSAT) in Southern Tanzania. We showed that mRDTs were more sensitive than local SMHS for diagnosing malaria infection. What are the implications for public health practices? Malaria rapid diagnostic tests can be useful as an alternative to SMHS for FSAT in the local context of Tanzania.
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Affiliation(s)
- Kangming Lin
- Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning City, Guangxi Zhuang Autonomous Region, China
| | - Mei Li
- National Institute of Parasitic Diseases, Chinese Center for Tropical Diseases Research, Chinese Center for Disease Control and Prevention; NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases; School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai Municipality, China
| | - Duoquan Wang
- National Institute of Parasitic Diseases, Chinese Center for Tropical Diseases Research, Chinese Center for Disease Control and Prevention; NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases; School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai Municipality, China
| | - Fei Luo
- Chongqing City Center for Disease Control and Prevention, Chongqing Municipality, China
| | - Shenning Lu
- National Institute of Parasitic Diseases, Chinese Center for Tropical Diseases Research, Chinese Center for Disease Control and Prevention; NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases; School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai Municipality, China
| | - Mihayo G Michael
- Ifakara Health Institute, Dares Salaam, the United Republic of Tanzania
| | - Yeromin Mlacha
- Ifakara Health Institute, Dares Salaam, the United Republic of Tanzania
| | - Prosper Chaki
- Ifakara Health Institute, Dares Salaam, the United Republic of Tanzania
| | - Ning Xiao
- National Institute of Parasitic Diseases, Chinese Center for Tropical Diseases Research, Chinese Center for Disease Control and Prevention; NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases; School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai Municipality, China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Tropical Diseases Research, Chinese Center for Disease Control and Prevention; NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases; School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai Municipality, China
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Comparison of Rapid Diagnostic Test, Microscopy, and Polymerase Chain Reaction for the Detection of Plasmodium falciparum Malaria in a Low-Transmission Area, Jazan Region, Southwestern Saudi Arabia. Diagnostics (Basel) 2022; 12:diagnostics12061485. [PMID: 35741295 PMCID: PMC9222139 DOI: 10.3390/diagnostics12061485] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/11/2022] [Accepted: 06/15/2022] [Indexed: 11/24/2022] Open
Abstract
This cross-sectional study aimed to assess the performances of a rapid diagnostic test (RDT)—the AllTest Malaria p.f./p.v., microscopy, and nested polymerase chain reaction (PCR) for diagnosing Plasmodium falciparum malaria in 400 febrile patients from a low-transmission region (Jazan) in southwestern Saudi Arabia. Diagnostic performance of all three methods was compared using microscopy and nested PCR as reference methods. Overall, 42 (10.5%), 48 (12.0%), and 57 (14.3%) samples were found positive by microscopy, RDT, and PCR, respectively. With PCR as reference method, the RDT showed higher sensitivity (79% vs. 71.9%), similar specificity (99.1% vs. 99.7%), and better NLR (0.20 vs. 0.27) and area under the curve (89.0% vs. 85.8%) than microscopy. The sensitivity of RDT and microscopy decreased as age increased, and false negatives were associated with low parasite density. In addition, the sensitivity of RDT and microscopy was higher in non-Saudi than in Saudi participants. Against microscopy, both RDT and PCR showed high sensitivity (83.3% vs. 97.6%), specificity (96.4% vs. 95.5%), and NPVs (98.0% vs. 99.7%), but reduced PPVs (72.9% vs. 71.9%), respectively. The results showed that the performance of the AllTest Malaria p.f./p.v RDT was better than that of microscopy in diagnosing P. falciparum malaria among febrile patients in the Jazan region when nested PCR was used as the reference. However, further studies are required to assess malaria diagnostic methods among asymptomatic individuals in the region.
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Onken A, Haanshuus CG, Miraji MK, Marijani M, Kibwana KO, Abeid KA, Mørch K, Reimers M, Langeland N, Müller F, Jenum PA, Blomberg B. Malaria prevalence and performance of diagnostic tests among patients hospitalized with acute undifferentiated fever in Zanzibar. Malar J 2022; 21:54. [PMID: 35183188 PMCID: PMC8858509 DOI: 10.1186/s12936-022-04067-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 01/31/2022] [Indexed: 12/04/2022] Open
Abstract
Background Control efforts in Zanzibar reduced the burden of malaria substantially from 2000 to 2015, but re-emergence of falciparum malaria has been observed lately. This study evaluated the prevalence of malaria and performance of routine diagnostic tests among hospitalized fever patients in a 1.5 years period in 2015 and 2016. Methods From March 2015 to October 2016, paediatric and adult patients hospitalized with acute undifferentiated fever at Mnazi Mmoja Hospital, Zanzibar were included. The malaria prevalence, and performance of rapid diagnostic test (RDT) and microscopy, were assessed using polymerase chain reaction (PCR) as gold standard. Results The malaria prevalence was 9% (63/731). Children under 5 years old had lower malaria prevalence (5%, 14/260) than older children (15%, 20/131, p = 0.001) and persons aged 16 to 30 years (13%, 15/119, p = 0.02), but not different from persons over 30 years old (6%, 14/217, p = 0.7). All cases had Plasmodium falciparum infection, except for one case of Plasmodium ovale. Ten malaria patients had no history of visiting mainland Tanzania. The RDT had a sensitivity of 64% (36/56) and a specificity of 98% (561/575), and microscopy had a sensitivity of 50% (18/36) and a specificity of 99% (251/254), compared to PCR. The malaria parasitaemia was lower in patients with false negative results on RDT (median 7 × 103 copies/µL, interquartile range [IQR] 2 × 103 – 8 × 104, p = 0.002) and microscopy (median 9 × 103 copies/µL, IQR 8 × 102 – 7 × 104, p = 0.006) compared to those with true positive RDT (median 2 × 105 copies/µL, IQR 3 × 104 – 5 × 105) and microscopy (median 2 × 105 copies/µL, IQR 6 × 104 – 5 × 105). Conclusions The study emphasizes that malaria was a frequent cause of febrile illness in hospitalized patients in Zanzibar in the years 2015-2016, particularly among school age children and young adults. We found evidence of autochthonous malaria transmission in Zanzibar. Compared to PCR, both RDT and microscopy had low sensitivity, and false negative results were associated with low parasitaemia. While low parasitaemia identified only by PCR in a semi-immune individual could be coincidental and without clinical relevance, clinicians should be aware of the risk of false negative results on routine tests.
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Alemayehu GS, Blackburn K, Lopez K, Cambel Dieng C, Lo E, Janies D, Golassa L. Detection of high prevalence of Plasmodium falciparum histidine-rich protein 2/3 gene deletions in Assosa zone, Ethiopia: implication for malaria diagnosis. Malar J 2021; 20:109. [PMID: 33622309 PMCID: PMC8095343 DOI: 10.1186/s12936-021-03629-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 02/06/2021] [Indexed: 11/10/2022] Open
Abstract
Background Rapid diagnostic tests (RDTs) targeting histidine rich protein 2(HRP2) are widely used for diagnosis of Plasmodium falciparum infections. Besides PfHRP2, the PfHRP3 antigen contributes to the detection of P. falciparum infections in PfHRP2 RDTs. However, the performance HRP2-based RDT is affected by pfhrp2/3 gene deletions resulting in false-negative test results. The objective of this study was to determine the presence and prevalence of pfhrp2/3 gene deletions including the respective flanking regions among symptomatic patients in Assosa zone, Northwest Ethiopia. Methods A health-facility based cross-sectional study was conducted in febrile patients seeking a malaria diagnosis in 2018. Blood samples were collected by finger-prick for microscopic examination of blood smears, malaria RDT, and molecular analysis using dried blood spots (DBS) prepared on Whatman filter paper. A total of 218 P. falciparum positive samples confirmed by quantitative PCR were included for molecular assay of pfhrp2/3 target gene. Results Of 218 P. falciparum positive samples, exon 2 deletions were observed in 17.9% of pfhrp2 gene and in 9.2% of pfhrp3 gene. A high proportion of deletions in short segments of pfhrp2 exon1-2 (50%) was also detected while the deletions of the pfhrp3 exon1-2 gene were 4.1%. The deletions were extended to the downstream and upstream of the flanking regions in pfhrp2/3 gene (above 30%). Of eighty-six PfHRP2 RDT negative samples, thirty-six lacked pfhrp2 exon 2. Five PfHRP2 RDT negative samples had double deletions in pfhrp2 exon 2 and pfhrp3 exon2. Of these double deletions, only two of the samples with a parasite density above 2000 parasite/µl were positive by the microscopy. Three samples with intact pfhrp3 exon2 in the pfhrp2 exon2 deleted parasite isolates were found to be positive by PfHRP2 RDT and microscopy with a parasite density above 10,000/µl. Conclusion This study confirms the presence of deletions of pfhrp2/3 gene including the flanking regions. Pfhrp2/3 gene deletions results in false-negative results undoubtedly affect the current malaria control and elimination effort in the country. However, further countrywide investigations are required to determine the magnitude of pfhrp2/3 gene deletions and its consequences on routine malaria diagnosis.
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Affiliation(s)
| | - Kayla Blackburn
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Karen Lopez
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Cheikh Cambel Dieng
- Department of Biological Sciences, Charlotte, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Eugenia Lo
- Department of Biological Sciences, Charlotte, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Daniel Janies
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Lemu Golassa
- Addis Ababa University, Aklilu Lemma Institute of Pathobiology, Addis Ababa, Ethiopia
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Góes L, Chamma-Siqueira N, Peres JM, Nascimento JM, Valle S, Arcanjo AR, Lacerda M, Blume L, Póvoa M, Viana G. Evaluation of Histidine-Rich Proteins 2 and 3 Gene Deletions in Plasmodium falciparum in Endemic Areas of the Brazilian Amazon. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 18:ijerph18010123. [PMID: 33375379 PMCID: PMC7795390 DOI: 10.3390/ijerph18010123] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/02/2020] [Accepted: 12/02/2020] [Indexed: 12/30/2022]
Abstract
Histidine-rich proteins 2 and 3 gene (pfhrp2 and pfhrp3) deletions affect the efficacy of rapid diagnostic tests (RDTs) based on the histidine-rich protein 2 (HRP2), compromising the correct identification of the Plasmodium falciparum species. Therefore, molecular surveillance is necessary for the investigation of the actual prevalence of this phenomenon and the extent of the disappearance of these genes in these areas and other South American countries, thus guiding national malaria control programs on the appropriate use of RDTs. This study aimed to evaluate the pfhrp2 and pfhrp3 gene deletion in P. falciparum in endemic areas of the Brazilian Amazon. Aliquots of DNA from the biorepository of the Laboratory of Basic Research in Malaria, Evandro Chagas Institute, with a positive diagnosis for P. falciparum infection as determined by microscopy and molecular assays, were included. Monoinfection was confirmed by nested-polymerase chain reaction assay, and DNA quality was assessed by amplification of the merozoite surface protein-2 gene (msp2). The pfhrp2 and pfhrp3 genes were amplified using primers for the region between exons 1 and 2 and for all extension of exon 2. Aliquots of DNA from 192 P. falciparum isolates were included in the study, with 68.7% (132/192) from the municipality of Cruzeiro do Sul (Acre) and 31.3% (60/192) from Manaus (Amazonas). Of this total, 82.8% (159/192) of the samples were considered of good quality. In the state of Acre, 71.7% (71/99) showed pfhrp2 gene deletion and 94.9% (94/99) showed pfhrp3 gene deletion, while in the state of Amazonas, 100.0% (60/60) of the samples showed pfhrp2 gene deletion and 98.3% (59/60) showed pfhrp3 gene deletion. Moreover, 79.8% (127/159) of isolates displayed gene deletion. Our findings confirm the presence of a parasite population with high frequencies of pfhrp2 and pfhrp3 gene deletions in the Brazilian Amazon region. This suggests reconsidering the use of HRP2-based RDTs in the Acre and Amazonas states and calls attention to the importance of molecular surveillance and mapping of pfhrp2/pfhrp3 deletions in this area and in other locations in the Amazon region to guarantee appropriate patient care, control and ultimately contribute to achieving P. falciparum malaria elimination.
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Affiliation(s)
- Leandro Góes
- Graduate Program in Epidemiology and Health Surveillance (PPGEVS), Centre for Education and Graduate Programs (NEP), Evandro Chagas Institute (IEC/SVS/MS), 67.030-000 Ananindeua, Pará, Brazil;
| | - Nathália Chamma-Siqueira
- Parasitology Section, Evandro Chagas Institute-IEC/SVS/MS, 67.030-000 Ananindeua, Pará, Brazil; (J.M.P.); (J.M.N.); (M.P.)
- Correspondence: (N.C.-S.); (G.V.)
| | - José Mário Peres
- Parasitology Section, Evandro Chagas Institute-IEC/SVS/MS, 67.030-000 Ananindeua, Pará, Brazil; (J.M.P.); (J.M.N.); (M.P.)
| | - José Maria Nascimento
- Parasitology Section, Evandro Chagas Institute-IEC/SVS/MS, 67.030-000 Ananindeua, Pará, Brazil; (J.M.P.); (J.M.N.); (M.P.)
| | - Suiane Valle
- Hemonúcleo Cruzeiro do Sul, State Health Department of Acre, 69.980-000 Cruzeiro do Sul, Acre, Brazil;
| | - Ana Ruth Arcanjo
- Central Public Health Laboratory of Amazonas (LACEN/Amazonas), 69.020-245 Manaus, Amazonas, Brazil;
| | - Marcus Lacerda
- Heitor Vieira Dourado Tropical Medicine Foundation, 69.040-000 Manaus, Brazil;
- Leônidas and Maria Deane Institute-Fiocruz Amazônia, 69.027-070 Manaus, Amazonas, Brazil
| | - Liana Blume
- Malaria Technical Group, General Coordination for the Monitoring of Zoonoses and Malaria Vector Transmission Diseases, CGZV Department of Immunization and Communicable Diseases, DEIDT, Health Surveillance Secretariat, SVS, Ministry of Health, 70.070-942 Brasília, Brazil;
| | - Marinete Póvoa
- Parasitology Section, Evandro Chagas Institute-IEC/SVS/MS, 67.030-000 Ananindeua, Pará, Brazil; (J.M.P.); (J.M.N.); (M.P.)
- National Council for Scientific and Technological Development, CNPq, 71.605-001 Brasília, Brazil
| | - Giselle Viana
- Parasitology Section, Evandro Chagas Institute-IEC/SVS/MS, 67.030-000 Ananindeua, Pará, Brazil; (J.M.P.); (J.M.N.); (M.P.)
- Correspondence: (N.C.-S.); (G.V.)
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Bath D, Goodman C, Yeung S. Modelling the cost-effectiveness of introducing subsidised malaria rapid diagnostic tests in the private retail sector in sub-Saharan Africa. BMJ Glob Health 2020; 5:bmjgh-2019-002138. [PMID: 32439690 PMCID: PMC7247415 DOI: 10.1136/bmjgh-2019-002138] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 03/17/2020] [Accepted: 03/21/2020] [Indexed: 11/18/2022] Open
Abstract
Background Over the last 10 years, there has been a huge shift in malaria diagnosis in public health facilities, due to widespread deployment of rapid diagnostic tests (RDTs), which are accurate, quick and easy to use and inexpensive. There are calls for RDTs to be made available at-scale in the private retail sector where many people with suspected malaria seek care. Retail sector RDT use in sub-Saharan Africa (SSA) is limited to small-scale studies, and robust evidence on value-for-money is not yet available. We modelled the cost-effectiveness of introducing subsidised RDTs and supporting interventions in the SSA retail sector, in a context of a subsidy programme for first-line antimalarials. Methods We developed a decision tree following febrile patients through presentation, diagnosis, treatment, disease progression and further care, to final health outcomes. We modelled results for three ‘treatment scenarios’, based on parameters from three small-scale studies in Nigeria (TS-N), Tanzania (TS-T) and Uganda (TS-U), under low and medium/high transmission (5% and 50% Plasmodium falciparum (parasite) positivity rates (PfPR), respectively). Results Cost-effectiveness varied considerably between treatment scenarios. Cost per disability-adjusted life year averted at 5% PfPR was US$482 (TS-N) and US$115 (TS-T) and at 50% PfPR US$44 (TS-N) and US$45 (TS-T), from a health service perspective. TS-U was dominated in both transmission settings. Conclusion The cost-effectiveness of subsidised RDTs is strongly influenced by treatment practices, for which further evidence is required from larger-scale operational settings. However, subsidised RDTs could promote increased use of first-line antimalarials in patients with malaria. RDTs may, therefore, be more cost-effective in higher transmission settings, where a greater proportion of patients have malaria and benefit from increased antimalarial use. This is contrary to previous public sector models, where RDTs were most cost-effective in lower transmission settings as they reduced unnecessary antimalarial use in patients without malaria.
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Affiliation(s)
- David Bath
- Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Catherine Goodman
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Shunmay Yeung
- Department of Clinical Research, Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
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10
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Plasmodium falciparum Histidine-Rich Protein 2 and 3 Gene Deletions and Their Implications in Malaria Control. Diseases 2020; 8:diseases8020015. [PMID: 32443811 PMCID: PMC7349124 DOI: 10.3390/diseases8020015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 04/25/2020] [Accepted: 05/05/2020] [Indexed: 01/15/2023] Open
Abstract
Malaria remains the biggest threat to public health, especially among pregnant women and young children in sub-Saharan Africa. Prompt and accurate diagnosis is critical for effective case management and detection of drug resistance. Conventionally, microscopy and rapid diagnostic tests (RDTs) are the tools of choice for malaria diagnosis. RDTs are simple to use and have been extensively used in the diagnosis of malaria among travelers to malaria-endemic regions, routine case management, and surveillance studies. Most RDTs target the histidine-rich protein (PfHRP) which is exclusively found in Plasmodium falciparum and a metabolic enzyme Plasmodium lactate dehydrogenase (pLDH) which is common among all Plasmodium species. Other RDTs incorporate the enzyme aldolase that is produced by all Plasmodium species. Recently, studies have reported false-negative RDTs primarily due to the deletion of the histidine-rich protein (pfhrp2 and pfhrp3) genes in field isolates of P. falciparum. Herein, we review published literature to establish pfhrp2/pfhrp3 deletions, the extent of these deletions in different geographical regions, and the implication in malaria control. We searched for publications on pfhrp2/pfhrp3 deletions and retrieved all publications that reported on this subject. Overall, 20 publications reported on pfhrp2/pfhrp3 deletions, and most of these studies were done in Central and South America, with very few in Asia and Africa. The few studies in Africa that reported on the occurrence of pfhrp2/pfhrp3 deletions rarely evaluated deletions on the flanking genes. More studies are required to evaluate the existence and extent of these gene deletions, whose presence may lead to delayed or missed treatment. This information will guide appropriate diagnostic approaches in the respective areas.
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11
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Ngasala B, Mutemi DD, Mwaiswelo RO. Diagnostic Performance of Malaria Rapid Diagnostic Test and Microscopy Compared with PCR for Detection of Plasmodium falciparum Infections among Primary Schoolchildren in Kibiti District, Eastern Tanzania: An Area with Moderate Malaria Transmission. Am J Trop Med Hyg 2020; 101:809-811. [PMID: 31436157 DOI: 10.4269/ajtmh.19-0394] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A substantial decline of malaria transmission intensity has been observed in sub-Saharan Africa over the past two decades and may affect the diagnostic performance of malaria rapid diagnostic test (mRDT) and microscopy. Diagnostic performance of histidine-rich protein II (HRP-II)/pan-lactate dehydrogenase (pLDH)-based mRDT and microscopy was evaluated against polymerase chain reaction (PCR) for the diagnosis of Plasmodium falciparum infection among 316 primary schoolchildren in Kibiti district, in 2016. Polymerase chain reaction detected more cases of P. falciparum infection than mRDT or microscopy. Using PCR as reference, the sensitivity and specificity of mRDT were 75.9% (95% CI = 62.8-86.1) and 96.9% (95% CI = 94.0-98.7), respectively, whereas that of microscopy were 63.8% (95% CI = 50.1-76.0) and 95.7% (95% CI = 92.5-97.9), respectively. Polymerase chain reaction and other molecular methods should be considered for use in schools and other epidemiological surveys as supplement to mRDT or microscopy.
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Affiliation(s)
- Billy Ngasala
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
| | - Doreen D Mutemi
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.,Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Richard O Mwaiswelo
- Department of Microbiology, Immunology and Parasitology, Hubert Kairuki Memorial University, Dar es Salaam, Tanzania.,Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
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12
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Grossenbacher B, Holzschuh A, Hofmann NE, Omar KA, Stuck L, Fakih BS, Ali A, Yukich J, Hetzel MW, Felger I. Molecular methods for tracking residual Plasmodium falciparum transmission in a close-to-elimination setting in Zanzibar. Malar J 2020; 19:50. [PMID: 31996210 PMCID: PMC6988349 DOI: 10.1186/s12936-020-3127-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/16/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Molecular detection of low-density Plasmodium falciparum infections is essential for surveillance studies conducted to inform malaria control strategies in close-to-elimination settings. Molecular monitoring of residual malaria infections usually requires a large study size, therefore sampling and diagnostic processes need to be economical and optimized for high-throughput. A method comparison was undertaken to identify the most efficient diagnostic procedure for processing large collections of community samples with optimal test sensitivity, simplicity, and minimal costs. METHODS In a reactive case detection study conducted on Zanzibar, parasitaemia of 4590 individuals of all ages was investigated by a highly sensitive quantitative (q) PCR that targets multiple var gene copies per parasite genome. To reduce cost, a first round of positivity screening was performed on pools of dried blood spots from five individuals. Ten cycles of a pre-PCR were performed directly on the filter paper punches, followed by qPCR. In a second round, samples of positive pools were individually analysed by pre-PCR and qPCR. RESULTS Prevalence in household members and neighbors of index cases was 1.7% (78/4590) with a geometric mean parasite density of 58 parasites/µl blood. Using qPCR as gold standard, diagnostic sensitivity of rapid diagnostic tests (RDTs) was 37% (29/78). Infections positive by qPCR but negative by RDT had mean densities of 15 parasites/µl blood. CONCLUSION The approach of pre-screening reactive case detection samples in pools of five was ideal for a low prevalence setting such as in Zanzibar. Performing direct PCR on filter paper punches saves substantial time and justifies the higher cost for a polymerase suitable for amplifying DNA directly from whole blood. Molecular monitoring in community samples provided a more accurate picture of infection prevalence, as it identified a potential reservoir of infection that was largely missed by RDT. The developed qPCR-based methodology for screening large sample sets represents primarily a research tool that should inform the design of malaria elimination strategies. It may also prove beneficial for diagnostic tasks in surveillance-response activities.
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Affiliation(s)
- Benjamin Grossenbacher
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Aurel Holzschuh
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Natalie E Hofmann
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Kali Abdullah Omar
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Logan Stuck
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA
| | | | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Joshua Yukich
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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13
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Abdalla ZA, Rahma NA, Hassan EE, Abdallah TM, Hamad HE, Omer SA, Adam I. The diagnostic performance of rapid diagnostic tests and microscopy for malaria diagnosis in eastern Sudan using a nested polymerase chain reaction assay as a reference standard. Trans R Soc Trop Med Hyg 2019; 113:701-705. [DOI: 10.1093/trstmh/trz069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/19/2019] [Accepted: 06/27/2019] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Accurate diagnosis of malaria infection is essential for successful control and management of the disease. Both microscopy and rapid diagnostic tests (RDTs) are recommended for malaria diagnosis, however, RDTs are more commonly used. The aim of the current study was to assess the performance of microscopy and RDTs in the diagnosis of Plasmodium falciparum infection using a nested polymerase chain reaction (PCR) assay as the gold standard.
Methods
A cross-sectional study was carried out in Kassala Hospital, eastern Sudan. A total of 341 febrile participants of all ages were recruited. Blood specimens were collected and malaria testing was performed using an RDT (SD Bioline Malaria Ag Pf), microscopy and nested PCR. The sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) of microscopy and the RDT were investigated.
Results
The prevalence of P. falciparum malaria infections in this study was 22.9%, 24.3% and 26.7% by PCR, microscopy and RDT, respectively. Compared with microscopy, the RDT had slightly higher sensitivity (80.7% vs 74.3%; p=0.442), equivalent specificity (89.3% vs 90.4%), a similar PPV (69.2% vs 69.8%) and a higher NPV (94.0% vs 92.2%).
Conclusions
The diagnostic performance of the RDT was better than that of microscopy in the diagnosis of P. falciparum malaria when nested PCR was used as the gold standard.
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Affiliation(s)
| | | | - Elhashimi E Hassan
- College of Applied Medical Sciences, Najran University, Najran, Saudi Arabia
| | | | - Hadeel E Hamad
- Department of Immunology and Biotechnology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Samia A Omer
- Department of Immunology and Biotechnology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Ishag Adam
- Faculty of Medicine, University of Khartoum, PO Box 102, Khartoum, Sudan
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14
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Dalrymple U, Cameron E, Arambepola R, Battle KE, Chestnutt EG, Keddie SH, Twohig KA, Pfeffer DA, Gibson HS, Weiss DJ, Bhatt S, Gething PW. The contribution of non-malarial febrile illness co-infections to Plasmodium falciparum case counts in health facilities in sub-Saharan Africa. Malar J 2019; 18:195. [PMID: 31186004 PMCID: PMC6560910 DOI: 10.1186/s12936-019-2830-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/04/2019] [Indexed: 01/20/2023] Open
Abstract
Background The disease burden of Plasmodium falciparum malaria illness is generally estimated using one of two distinct approaches: either by transforming P. falciparum infection prevalence estimates into incidence estimates using conversion formulae; or through adjustment of counts of recorded P. falciparum-positive fever cases from clinics. Whilst both ostensibly seek to evaluate P. falciparum disease burden, there is an implicit and problematic difference in the metric being estimated. The first enumerates only symptomatic malaria cases, while the second enumerates all febrile episodes coincident with a P. falciparum infection, regardless of the fever’s underlying cause. Methods Here, a novel approach was used to triangulate community-based data sources capturing P. falciparum infection, fever, and care-seeking to estimate the fraction of P. falciparum-positive fevers amongst children under 5 years of age presenting at health facilities that are attributable to P. falciparum infection versus other non-malarial causes. A Bayesian hierarchical model was used to assign probabilities of malaria-attributable fever (MAF) and non-malarial febrile illness (NMFI) to children under five from a dataset of 41 surveys from 21 countries in sub-Saharan Africa conducted between 2006 and 2016. Using subsequent treatment-seeking outcomes, the proportion of MAF and NMFI amongst P. falciparum-positive febrile children presenting at public clinics was estimated. Results Across all surveyed malaria-positive febrile children who sought care at public clinics across 41 country-years in sub-Saharan Africa, P. falciparum infection was estimated to be the underlying cause of only 37.7% (31.1–45.4, 95% CrI) of P. falciparum-positive fevers, with significant geographical and temporal heterogeneity between surveys. Conclusions These findings highlight the complex nature of the P. falciparum burden amongst children under 5 years of age and indicate that for many children presenting at health clinics, a positive P. falciparum diagnosis and a fever does not necessarily mean P. falciparum is the underlying cause of the child’s symptoms, and thus other causes of illness should always be investigated, in addition to prescribing an effective anti-malarial medication. In addition to providing new large-scale estimates of malaria-attributable fever prevalence, the results presented here improve comparability between different methods for calculating P. falciparum disease burden, with significant implications for national and global estimation of malaria burden. Electronic supplementary material The online version of this article (10.1186/s12936-019-2830-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ursula Dalrymple
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK.,Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford, OX1 3SZ, UK
| | - Ewan Cameron
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Rohan Arambepola
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Katherine E Battle
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Elisabeth G Chestnutt
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Suzanne H Keddie
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Katherine A Twohig
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Daniel A Pfeffer
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK.,Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Harry S Gibson
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Daniel J Weiss
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Samir Bhatt
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK.,School of Public Health, Faculty of Medicine, Imperial College London, St Mary's Hospital, Norfolk Place, London, W2 1PG, UK
| | - Peter W Gething
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK.
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15
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Ajibaye O, Balogun EO, Olukosi YA, Orok BA, Oyebola KM, Iwalokun BA, Aina OO, Shittu O, Adeneye AK, Ojewunmi OO, Kita K, Awolola ST. Impact of training of mothers, drug shop attendants and voluntary health workers on effective diagnosis and treatment of malaria in Lagos, Nigeria. Trop Parasitol 2019; 9:36-44. [PMID: 31161091 PMCID: PMC6542308 DOI: 10.4103/tp.tp_36_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2019] [Indexed: 11/08/2022] Open
Abstract
Background: The National Malaria Eradication Program and international agencies are keen on scaling up the use of malaria rapid diagnostic tests (mRDTs) and artemisinin-based combination therapies (ACTs) for effective diagnosis and treatment of the disease. However, poor diagnostic skills and inappropriate treatment are limiting the efforts. In Nigeria, a large proportion of infected patients self-diagnose and treat while many others seek care from informal drug attendants and voluntary health workers. Aims: This study describes the impact of training voluntary health workers, drug shop attendants, and mothers on effective case detection and treatment of malaria in Lagos, Nigeria. METHODS: We trained mothers accessing antenatal care, drug shop attendants, and voluntary health workers selected from the three districts of Lagos, on the use of histidine-rich protein-2-based mRDTs and ACTs. Pre- and post-training assessments, focus group discussions (FGDs), and in-depth interviews (IDIs) were carried out. Results: The knowledge, attitude, and skill of the participants to achieve the goal of “test, treat, and track” using mRDT and ACTs were low (11%–55%). There was a low awareness of other non-malaria fevers among mothers. Self-medication was widely practiced (31.3%). FGDs and IDIs revealed that health-care providers administered antimalarials without diagnosis. Training significantly improved participants' knowledge and expertise on the use of mRDTs and ACTs (P = 0.02). The participants' field performance on mRDT use was significantly correlated with their category (bivariate r = 0.51, P = 0.001). There was no statistically significant association between the participants' level of education or previous field experience and their field performance on mRDT (r = 0.12, P = 0.9; χ
2= 38, df = 2 and P = 0.49). Conclusion: These findings suggest that training of stakeholders in malaria control improves diagnosis and treatment of malaria. However, a broader scope of training in other settings may be required for an effective malaria control in Nigeria.
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Affiliation(s)
- Olusola Ajibaye
- Department of Biochemistry and Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Emmanuel O Balogun
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.,Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yetunde A Olukosi
- Department of Biochemistry and Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Bassey A Orok
- Department of Biochemistry and Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Kolapo M Oyebola
- Department of Biochemistry and Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Bamidele A Iwalokun
- Department of Molecular Biology and Biotechnology, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Olugbenga O Aina
- Department of Biochemistry and Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Olalere Shittu
- Department of Zoology, Parasitology Unit, University of Ilorin, Ilorin, Nigeria
| | - Adeniyi K Adeneye
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | | | - K Kita
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Samson T Awolola
- Department of Public Health and Molecular Entomology, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
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16
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Hawash Y, Ismail K, Alsharif K, Alsanie W. Malaria Prevalence in a Low Transmission Area, Jazan District of Southwestern Saudi Arabia. THE KOREAN JOURNAL OF PARASITOLOGY 2019; 57:233-242. [PMID: 31284345 PMCID: PMC6616166 DOI: 10.3347/kjp.2019.57.3.233] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/24/2019] [Accepted: 05/03/2019] [Indexed: 11/23/2022]
Abstract
Detailed description of malaria in low transmission areas is crucial for elimination. The current study aimed to provide a comprehensive description for malaria transmission in Jazan, a low transmission district, southwestern Saudi Arabia. Patients at a tertiary care hospital were recruited in our study between August 2016 and September 2018. Malaria diagnosis was performed through a species-specific nested polymerase chain reaction (nested PCR), microscopy and Paramax-3TM rapid detection test (RDT). Malaria was detected in 30 patients by the PCR, with point prevalence of 10.9%. Of these malaria infections, 80% was imported, 26.6% was asymptomatic and 23.3% was sub-microscopic. Malaria was reported throughout the year, with February/March and September/October peaks. Infection was significantly more in males than in females (P=0.01). Likewise, infections were detected more in febrile than in non-febrile patients (P=0.01). Adult aged 15-24 years, fever and travel were identified as high-risk factors. Malaria was primarily attributed to Plasmodium falciparum mono-infections, followed by P. vivax mono-infections and lastly to falciparum/vivax mixed infections accounting 76.6%, 16.6%, and 6.6% of PCR-confirmed malaria cases, respectively. The nested PCR was superior to the smear microscopy (sensitivity 76.6%; specificity 100%) and the RDT (sensitivity 83.3%, specificity 94.2%). The overall percent agreement between microscopy and the RDT was 92.7% (kappa=0.63). High proportion of imported malaria including sub-microscopic and sub-patent cases were described. We suggest that incorporation of molecular tool into the conventional malaria diagnosis is beneficial in Jazan district.
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Affiliation(s)
- Yousry Hawash
- Clinical Laboratories Sciences Department, College of Applied Medical Science, Taif University, Taif,
Saudi Arabia
- Parasitology Department, National Liver Institute, Menoufia University, Menoufia,
Egypt
| | - Khadiga Ismail
- Clinical Laboratories Sciences Department, College of Applied Medical Science, Taif University, Taif,
Saudi Arabia
- Parasitology Department, Faculty of Medicine, Ain-Shams University, Cairo,
Egypt
| | - Khalaf Alsharif
- Clinical Laboratories Sciences Department, College of Applied Medical Science, Taif University, Taif,
Saudi Arabia
| | - Walaa Alsanie
- Clinical Laboratories Sciences Department, College of Applied Medical Science, Taif University, Taif,
Saudi Arabia
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17
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Sitali L, Miller JM, Mwenda MC, Bridges DJ, Hawela MB, Hamainza B, Chizema-Kawesha E, Eisele TP, Chipeta J, Lindtjørn B. Distribution of Plasmodium species and assessment of performance of diagnostic tools used during a malaria survey in Southern and Western Provinces of Zambia. Malar J 2019; 18:130. [PMID: 30971231 PMCID: PMC6458729 DOI: 10.1186/s12936-019-2766-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/04/2019] [Indexed: 11/10/2022] Open
Abstract
Background Zambia continues to make strides in reducing malaria burden through the use of proven malaria interventions and has recently pledged to eliminate malaria by 2021. Case management services have been scaled up at community level with rapid diagnostic tests (RDTs) providing antigen-based detection of falciparum malaria only. Key to national malaria elimination goals is the ability to identify, treat and eliminate all Plasmodium species. This study sought to determine the distribution of non-falciparum malaria and assess the performance of diagnostic tests for Plasmodium falciparum in Western and Southern Provinces of Zambia, two provinces planned for early malaria elimination. Methods A sub-set of individuals’ data and samples from a cross-sectional household survey, conducted during peak malaria transmission season in April and May 2017, was used. The survey collected socio-demographic information on household members and coverage of malaria interventions. Malaria testing was done on respondents of all ages using blood smears and RDTs while dried blood spots were collected on filter papers for analysis using photo-induced electron transfer polymerase chain reaction (PET-PCR). Slides were stained using Giemsa stain and examined by microscopy for malaria parasites. Results From the 1567 individuals included, the overall prevalence of malaria was 19.4% (CI 17.5–21.4) by PCR, 19.3% (CI 17.4–21.4) by RDT and 12.9% (CI 11.3–14.7) by microscopy. Using PET-PCR as the gold standard, RDTs showed a sensitivity of 75.7% (CI 70.4–80.4) and specificity of 94.2% (CI 92.8–95.4). The positive predictive value (PPV) was 75.9% (CI 70.7–80.6) and negative predictive value (NPV) was 94.1% (CI 92.1–95.4). In contrast, microscopy for sensitivity, specificity, PPV, and NPV values were 56.9% (CI 51.1–62.5), 97.7% (CI 96.7–98.5), 85.6% (CI 80.0–90.2), 90.4% (CI 88.7–91.9), respectively. Non-falciparum infections were found only in Western Province, where 11.6% of P. falciparum infections were co-infections with Plasmodium ovale or Plasmodium malariae. Conclusion From the sub-set of survey data analysed, non-falciparum species are present and occurred as mixed infections. As expected, PET-PCR was slightly more sensitive than both malaria RDTs and microscopy to detecting malaria infections.
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Affiliation(s)
- Lungowe Sitali
- Centre for International Health, Faculty of Medicine, University of Bergen, Bergen, Norway. .,Department of Biomedical Science, School of Health Sciences, University of Zambia, Lusaka, Zambia. .,School of Medicine and University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Lusaka, Zambia.
| | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds, Lusaka, Zambia
| | - Mulenga C Mwenda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds, Lusaka, Zambia
| | - Daniel J Bridges
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds, Lusaka, Zambia
| | - Moonga B Hawela
- National Malaria Elimination Centre, Ministry of Health, Chainama Hospital and College Grounds, Lusaka, Zambia
| | - Busiku Hamainza
- National Malaria Elimination Centre, Ministry of Health, Chainama Hospital and College Grounds, Lusaka, Zambia
| | - Elizabeth Chizema-Kawesha
- National Malaria Elimination Centre, Ministry of Health, Chainama Hospital and College Grounds, Lusaka, Zambia
| | - Thomas P Eisele
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA.,Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - James Chipeta
- School of Medicine and University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Lusaka, Zambia.,Department of Paediatrics and Child Health, University of Zambia School of Medicine, Lusaka, Zambia
| | - Bernt Lindtjørn
- Centre for International Health, Faculty of Medicine, University of Bergen, Bergen, Norway
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18
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Björkman A, Shakely D, Ali AS, Morris U, Mkali H, Abbas AK, Al-Mafazy AW, Haji KA, Mcha J, Omar R, Cook J, Elfving K, Petzold M, Sachs MC, Aydin-Schmidt B, Drakeley C, Msellem M, Mårtensson A. From high to low malaria transmission in Zanzibar-challenges and opportunities to achieve elimination. BMC Med 2019; 17:14. [PMID: 30665398 PMCID: PMC6341737 DOI: 10.1186/s12916-018-1243-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 12/17/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Substantial global progress in the control of malaria in recent years has led to increased commitment to its potential elimination. Whether this is possible in high transmission areas of sub-Saharan Africa remains unclear. Zanzibar represents a unique case study of such attempt, where modern tools and strategies for malaria treatment and vector control have been deployed since 2003. METHODS We have studied temporal trends of comprehensive malariometric indices in two districts with over 100,000 inhabitants each. The analyses included triangulation of data from annual community-based cross-sectional surveys, health management information systems, vital registry and entomological sentinel surveys. RESULTS The interventions, with sustained high-community uptake, were temporally associated with a major malaria decline, most pronounced between 2004 and 2007 and followed by a sustained state of low transmission. In 2015, the Plasmodium falciparum community prevalence of 0.43% (95% CI 0.23-0.73) by microscopy or rapid diagnostic test represented 96% reduction compared with that in 2003. The P. falciparum and P. malariae prevalence by PCR was 1.8% (95% CI 1.3-2.3), and the annual P. falciparum incidence was estimated to 8 infections including 2.8 clinical episodes per 1000 inhabitants. The total parasite load decreased over 1000-fold (99.9%) between 2003 and 2015. The incidence of symptomatic malaria at health facilities decreased by 94% with a trend towards relatively higher incidence in age groups > 5 years, a more pronounced seasonality and with reported travel history to/from Tanzania mainland as a higher risk factor. All-cause mortality among children < 5 years decreased by 72% between 2002 and 2007 mainly following the introduction of artemisinin-based combination therapies whereas the main reduction in malaria incidence followed upon the vector control interventions from 2006. Human biting rates decreased by 98% with a major shift towards outdoor biting by Anopheles arabiensis. CONCLUSIONS Zanzibar provides new evidence of the feasibility of reaching uniquely significant and sustainable malaria reduction (pre-elimination) in a previously high endemic region in sub-Saharan Africa. The data highlight constraints of optimistic prognostic modelling studies. New challenges, mainly with outdoor transmission, a large asymptomatic parasite reservoir and imported infections, require novel tools and reoriented strategies to prevent a rebound effect and achieve elimination.
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Affiliation(s)
- A Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.
| | - D Shakely
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.,Health Metrics at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - A S Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - U Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden
| | - H Mkali
- MEASURE Evaluation, Dar es Salaam, Tanzania
| | - A K Abbas
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - A-W Al-Mafazy
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - K A Haji
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - J Mcha
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - R Omar
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - J Cook
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.,London School of Hygiene and Tropical Medicine, London, UK
| | - K Elfving
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.,Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
| | - M Petzold
- Centre for Applied Biostatistics, University of Gothenburg, Gothenburg, Sweden
| | - M C Sachs
- Biostatistics Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - B Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden
| | - C Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - M Msellem
- Training and Research, Mnazi Mmoja Hospital, Zanzibar, Tanzania
| | - A Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
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19
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Berzosa P, de Lucio A, Romay-Barja M, Herrador Z, González V, García L, Fernández-Martínez A, Santana-Morales M, Ncogo P, Valladares B, Riloha M, Benito A. Comparison of three diagnostic methods (microscopy, RDT, and PCR) for the detection of malaria parasites in representative samples from Equatorial Guinea. Malar J 2018; 17:333. [PMID: 30223852 PMCID: PMC6142353 DOI: 10.1186/s12936-018-2481-4] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 09/10/2018] [Indexed: 11/21/2022] Open
Abstract
Background Malaria in Equatorial Guinea remains a major public health problem. The country is a holo-endemic area with a year-round transmission pattern. In 2016, the prevalence of malaria was 12.09% and malaria caused 15% of deaths among children under 5 years. In the Continental Region, 95.2% of malaria infections were Plasmodium falciparum, 9.5% Plasmodium vivax, and eight cases mixed infection in 2011. The main strategy for malaria control is quick and accurate diagnosis followed by effective treatment. Early and accurate diagnosis of malaria is essential for both effective disease management and malaria surveillance. The quality of malaria diagnosis is important in all settings, as misdiagnosis can result in significant morbidity and mortality. Microscopy and RDTs are the primary choices for diagnosing malaria in the field. However, false-negative results may delay treatment and increase the number of persons capable of infecting mosquitoes in the community. The present study analysed the performance of microscopy and RDTs, the two main techniques used in Equatorial Guinea for the diagnosis of malaria, compared to semi-nested multiplex PCR (SnM-PCR). Results A total of 1724 samples tested by microscopy, RDT, and SnM-PCR were analysed. Among the negative samples detected by microscopy, 335 (19.4%) were false negatives. On the other hand, the negative samples detected by RDT, 128 (13.3%) were false negatives based on PCR. This finding is important, especially since it is a group of patients who did not receive antimalarial treatment. Conclusions Owing to the high number of false negatives in microscopy, it is necessary to reinforce training in microscopy, the “Gold Standard” in endemic areas. A network of reference centres could potentially support ongoing diagnostic and control efforts made by malaria control programmes in the long term, as the National Centre of Tropical Medicine currently supports the National Programme against Malaria of Equatorial Guinea to perform all of the molecular studies necessary for disease control. Taking into account the results obtained with the RDTs, an exhaustive study of the deletion of the hrp2 gene must be done in EG to help choose the correct RDT for this area.
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Affiliation(s)
- Pedro Berzosa
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain. .,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain.
| | - Aida de Lucio
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain
| | - María Romay-Barja
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain
| | - Zaida Herrador
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain
| | - Vicenta González
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain
| | - Luz García
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain
| | - Amalia Fernández-Martínez
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain
| | - Maria Santana-Morales
- Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain.,Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de la Laguna, Tenerife, Spain
| | - Policarpo Ncogo
- Reference Centre for Control of Endemic Diseases (CRCE), Malabo, Equatorial Guinea
| | - Basilio Valladares
- Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain.,Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de la Laguna, Tenerife, Spain
| | - Matilde Riloha
- Ministry of Health and Social Welfare of Equatorial Guinea, Malabo, Equatorial Guinea
| | - Agustín Benito
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.,Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain
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20
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Comparison of visual and automated Deki Reader interpretation of malaria rapid diagnostic tests in rural Tanzanian military health facilities. Malar J 2018; 17:214. [PMID: 29843721 PMCID: PMC5975443 DOI: 10.1186/s12936-018-2363-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/22/2018] [Indexed: 12/03/2022] Open
Abstract
Background Although microscopy is a standard diagnostic tool for malaria and the gold standard, it is infrequently used because of unavailability of laboratory facilities and the absence of skilled readers in poor resource settings. Malaria rapid diagnostic tests (RDT) are currently used instead of or as an adjunct to microscopy. However, at very low parasitaemia (usually < 100 asexual parasites/µl), the test line on malaria rapid diagnostic tests can be faint and consequently hard to visualize and this may potentially affect the interpretation of the test results. Fio Corporation (Canada), developed an automated RDT reader named Deki Reader™ for automatic analysis and interpretation of rapid diagnostic tests. This study aimed to compare visual assessment and automated Deki Reader evaluations to interpret malaria rapid diagnostic tests against microscopy. Unlike in the previous studies where expert laboratory technicians interpreted the test results visually and operated the device, in this study low cadre health care workers who have not attended any formal professional training in laboratory sciences were employed. Methods Finger prick blood from 1293 outpatients with fever was tested for malaria using RDT and Giemsa-stained microscopy for thick and thin blood smears. Blood samples for RDTs were processed according to manufacturers’ instructions automated in the Deki Reader. Results of malaria diagnoses were compared between visual and the automated devise reading of RDT and microscopy. Results The sensitivity of malaria rapid diagnostic test results interpreted by the Deki Reader was 94.1% and that of visual interpretation was 93.9%. The specificity of malaria rapid diagnostic test results was 71.8% and that of human interpretation was 72.0%. The positive predictive value of malaria RDT results by the Deki Reader and visual interpretation was 75.8 and 75.4%, respectively, while the negative predictive values were 92.8 and 92.4%, respectively. The accuracy of RDT as interpreted by DR and visually was 82.6 and 82.1%, respectively. Conclusion There was no significant difference in performance of RDTs interpreted by either automated DR or visually by unskilled health workers. However, despite the similarities in performance parameters, the device has proven useful because it provides stepwise guidance on processing RDT, data transfer and reporting.
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21
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Dapás JI, Quirós RE. Antimicrobial Stewardship in Low- and Middle-Income Countries. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2018. [DOI: 10.1007/s40506-018-0141-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Singlovic J, Ajayi IO, Nsungwa-Sabiiti J, Siribié M, Sanou AK, Jegede AS, Falade CO, Sermé L, Gansane Z, Afonne C, Kabarungi V, Kyaligonza J, Castellani J, Petzold M, Gomes M. Compliance With Malaria Rapid Diagnostic Testing by Community Health Workers in 3 Malaria-Endemic Countries of Sub-Saharan Africa: An Observational Study. Clin Infect Dis 2018; 63:S276-S282. [PMID: 27941105 PMCID: PMC5146698 DOI: 10.1093/cid/ciw626] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background. The World Health Organization recommends that all malaria management be based on parasitological identification. We monitored performance of trained community health workers (CHWs) in adhering to this recommendation to restrict artemisinin-based combination therapies (ACTs) to positive rapid diagnostic test (RDT)–confirmed cases in children in 3 malaria-endemic sub-Saharan African countries. Methods. In 33 villages in Burkina Faso, 45 villages in Nigeria, and 84 villages in Uganda, 265 CHWs were trained over a minimum of 3 days to diagnose malaria using RDTs (prepare, read, record results, and inform the patient about results) and treat RDT-confirmed uncomplicated malaria cases with ACTs. In Nigeria, CHWs were also taught to obtain a thick blood smear. Spent RDT kits and prepared blood slides were collected and interpreted independently in Burkina Faso and Nigeria to confirm CHWs' diagnoses. Interviews were held with 12 of 17 CHWs who prescribed ACTs for patients with RDT-negative test results, and with 16 of 29 caregivers to determine factors related to noncompliance. Results. Of 12 656 patients treated with ACTs in the participating countries (5365 in Burkina Faso, 1648 in Nigeria, and 5643 in Uganda), 29 patients (8 from Burkina Faso, 17 from Nigeria, 4 from Uganda) were RDT negative. The small number of RDT-negative ACT-treated cases limits statistical analysis. Only a few CHWs were involved, and they were more likely to be traders rather than farmers (odds ratio [OR], 6.15; 95% confidence interval [CI], 2.09–18.07; P = .0004). RDT-negative children who were treated with ACTs had a significantly higher probability of residing in a village other than that of the CHW (OR, 3.85; 95% CI, 1.59–9.30; P = .0018). Parental pressure was identified in interviews with parents. Conclusions. Noncompliance with results of RDT tests is relatively rare when CHWs are trained and well supervised. Clinical Trials Registration. ISRCTN13858170.
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Affiliation(s)
- Jan Singlovic
- UNICEF/UNDP/World Bank/WHO Special Programme for Research & Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - IkeOluwapo O Ajayi
- Department of Epidemiology and Medical Statistics, College of Medicine, University of Ibadan, Nigeria
| | | | | | - Armande K Sanou
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | | | | | - Luc Sermé
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | - Zakaria Gansane
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | - Chinenye Afonne
- Epidemiology and Biostatistics Research Unit, Institute of Advanced Medical Research and Training, College of Medicine, University of Ibadan, Nigeria
| | | | | | - Joëlle Castellani
- Department of Health Services Research, School for Public Health and Primary Care, Maastricht University, The Netherlands
| | - Max Petzold
- Centre for Applied Biostatistics, Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Melba Gomes
- UNICEF/UNDP/World Bank/WHO Special Programme for Research & Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
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23
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Ranadive N, Kunene S, Darteh S, Ntshalintshali N, Nhlabathi N, Dlamini N, Chitundu S, Saini M, Murphy M, Soble A, Schwartz A, Greenhouse B, Hsiang MS. Limitations of Rapid Diagnostic Testing in Patients with Suspected Malaria: A Diagnostic Accuracy Evaluation from Swaziland, a Low-Endemicity Country Aiming for Malaria Elimination. Clin Infect Dis 2018; 64:1221-1227. [PMID: 28369268 PMCID: PMC5399938 DOI: 10.1093/cid/cix131] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/18/2017] [Indexed: 11/14/2022] Open
Abstract
Background. The performance of Plasmodium falciparum–specific histidine-rich protein 2–based rapid diagnostic tests (RDTs) to evaluate suspected malaria in low-endemicity settings has not been well characterized. Methods. Using dried blood spot samples from patients with suspected malaria at 37 health facilities from 2012 to 2014 in the low-endemicity country of Swaziland, we investigated the diagnostic accuracy of histidine-rich protein 2–based RDTs using qualitative polymerase chain reaction (PCR) (nested PCR targeting the cytochrome b gene) and quantitative PCR as reference standards. To explore reasons for false-negative and/or false-positive results, we used pfhrp2/3-specific PCR and logistic regression analyses of potentially associated epidemiological factors. Results. From 1353 patients, 93.0% of RDT-positive (n = 185) and 31.2% of RDT-negative samples (n = 340) were available and selected for testing. Compared with nested PCR, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RDTs were 51.7%, 94.1%, 67.3%, and 89.1%, respectively. After exclusion of samples with parasite densities <100/μL, which accounted for 75.7% of false-negative results and 33.3% of PCR-detectable infections, the sensitivity, specificity, PPV, and NPV were 78.8%, 93.7%, 62.3%, and 97.1%. Deletions of pfhrp2 were not detected. False-positivity was more likely during the second year and was not associated with demographics, recent malaria, health facility testing characteristics, or potential DNA degradation. Conclusions. In the low-transmission setting of Swaziland, we demonstrated low sensitivity of RDT for malaria diagnosis, owing to an unexpectedly high proportion of low-density infection among symptomatic subjects. The PPV was also low, requiring further investigation. A more accurate point-of-care diagnostic may be needed to support malaria elimination efforts.
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Affiliation(s)
| | - Simon Kunene
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Sarah Darteh
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | | | - Nomcebo Nhlabathi
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Nomcebo Dlamini
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Stanley Chitundu
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Manik Saini
- Clinton Health Access Initiative, Mbabane, Swaziland
| | - Maxwell Murphy
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Adam Soble
- Clinton Health Access Initiative, Mbabane, Swaziland
| | - Alanna Schwartz
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco (UCSF), San Francisco, CA, USA.,Department of Pediatrics, Benioff Children's Hospital and University of California, San Francisco, CA, USA.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA
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24
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Hsiang MS, Ranadive N, Chitundu S, Ntshalintshali N, Greenhouse B. Reply to Rossi et al. Clin Infect Dis 2017; 65:1770-1771. [PMID: 29020318 PMCID: PMC5850315 DOI: 10.1093/cid/cix627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas
- Malaria Elimination Initiative, Global Health Group
- Department of Pediatrics, University of California, San Francisco Benioff Children’s Hospital
| | - Nikhil Ranadive
- Global Health Sciences
- Emory University School of Medicine, Atlanta, Georgia
| | | | | | - Bryan Greenhouse
- Department of Medicine, San Francisco General Hospital, University of California
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25
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Boyce MR, O'Meara WP. Use of malaria RDTs in various health contexts across sub-Saharan Africa: a systematic review. BMC Public Health 2017; 17:470. [PMID: 28521798 PMCID: PMC5437623 DOI: 10.1186/s12889-017-4398-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 05/08/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The World Health Organization recommends parasitological confirmation of malaria prior to treatment. Malaria rapid diagnostic tests (RDTs) represent one diagnostic method that is used in a variety of contexts to overcome limitations of other diagnostic techniques. Malaria RDTs increase the availability and feasibility of accurate diagnosis and may result in improved quality of care. Though RDTs are used in a variety of contexts, no studies have compared how well or effectively RDTs are used across these contexts. This review assesses the diagnostic use of RDTs in four different contexts: health facilities, the community, drug shops and schools. METHODS A comprehensive search of the Pubmed database was conducted to evaluate RDT execution, test accuracy, or adherence to test results in sub-Saharan Africa. Original RDT and Plasmodium falciparum focused studies conducted in formal health care facilities, drug shops, schools, or by CHWs between the year 2000 and December 2016 were included. Studies were excluded if they were conducted exclusively in a research laboratory setting, where staff from the study team conducted RDTs, or in settings outside of sub-Saharan Africa. RESULTS The literature search identified 757 reports. A total of 52 studies were included in the analysis. Overall, RDTs were performed safely and effectively by community health workers provided they receive proper training. Analogous information was largely absent for formal health care workers. Tests were generally accurate across contexts, except for in drug shops where lower specificities were observed. Adherence to RDT results was higher among drug shop vendors and community health workers, while adherence was more variable among formal health care workers, most notably with negative test results. CONCLUSIONS Malaria RDTs are generally used well, though compliance with test results is variable - especially in the formal health care sector. If low adherence rates are extrapolated, thousands of patients may be incorrectly diagnosed and receive inappropriate treatment resulting in a low quality of care and unnecessary drug use. Multidisciplinary research should continue to explore determinants of good RDT use, and seek to better understand how to support and sustain the correct use of this diagnostic tool.
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Affiliation(s)
| | - Wendy P O'Meara
- Duke Global Health Institute, Durham, NC, USA.,School of Public Health, Moi University College of Health Sciences, Eldoret, Kenya
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26
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Kozycki CT, Umulisa N, Rulisa S, Mwikarago EI, Musabyimana JP, Habimana JP, Karema C, Krogstad DJ. False-negative malaria rapid diagnostic tests in Rwanda: impact of Plasmodium falciparum isolates lacking hrp2 and declining malaria transmission. Malar J 2017; 16:123. [PMID: 28320390 PMCID: PMC5359811 DOI: 10.1186/s12936-017-1768-1] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/08/2017] [Indexed: 11/10/2022] Open
Abstract
Background Rapid diagnostic tests (RDTs) for histidine rich protein 2 (HRP2) are often used to determine whether persons with fever should be treated with anti-malarials. However, Plasmodium falciparum parasites with a deletion of the hrp2 gene yield false-negative RDTs and there are concerns the sensitivity of HRP2-based RDTs may fall when the intensity of transmission decreases. Methods This observational study enrolled 9226 patients at three health centres in Rwanda from April 2014 to April 2015. It then compared the sensitivity of RDTs based on HRP2 and the Plasmodium lactate dehydrogenase (pLDH) to microscopy (thick smears) for the diagnosis of malaria. PCR was used to determine whether deletions of the histidine-rich central repeat region of the hrp2 gene (exon 2) were associated with false-negative HRP2-based RDTs. Results In comparison to microscopy, the sensitivity and specificity of HRP2- and pLDH-based RDTs were 89.5 and 86.2% and 80.2 and 94.3%, respectively. When the results for both RDTs were combined, sensitivity rose to 91.8% and specificity was 85.7%. Additionally, when smear positivity fell from 46 to 3%, the sensitivity of the HRP2-based RDT fell from 88 to 67%. Of 370 samples with false-negative HRP2 RDT results for which PCR was performed, 140 (38%) were identified as P. falciparum by PCR. Of the isolates identified as P. falciparum by PCR, 32 (23%) were negative for the hrp2 gene based on PCR. Of the 32 P. falciparum isolates negative for hrp2 by PCR, 17 (53%) were positive based on the pLDH RDT. Conclusion This prospective study of RDT performance coincided with a decline in the intensity of malaria transmission in Kibirizi (fall in slide positivity from 46 to 3%). This decline was associated with a decrease in HRP2 RDT sensitivity (from 88 to 67%). While P. falciparum isolates without the hrp2 gene were an important cause of false-negative HRP2-based RDTs, most were identified by the pLDH-based RDT. Although WHO does not recommend the use of combined HRP2/pLDH testing in sub-Saharan Africa, these results suggest that combination HRP2/pLDH-based RDTs could reduce the impact of false-negative HRP2-based RDTs for detection of symptomatic P. falciparum malaria. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1768-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Noella Umulisa
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda.,Maternal and Child Survival Programme, Jhpiego, Kigali, Rwanda
| | - Stephen Rulisa
- School of Medicine and Pharmacy, University of Rwanda, Kigali, Rwanda
| | - Emil I Mwikarago
- National Reference Laboratory, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda
| | | | - Jean Pierre Habimana
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda
| | - Corine Karema
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Quality and Equity Healthcare, Kigali, Rwanda
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27
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Burchett HED, Leurent B, Baiden F, Baltzell K, Björkman A, Bruxvoort K, Clarke S, DiLiberto D, Elfving K, Goodman C, Hopkins H, Lal S, Liverani M, Magnussen P, Mårtensson A, Mbacham W, Mbonye A, Onwujekwe O, Roth Allen D, Shakely D, Staedke S, Vestergaard LS, Whitty CJM, Wiseman V, Chandler CIR. Improving prescribing practices with rapid diagnostic tests (RDTs): synthesis of 10 studies to explore reasons for variation in malaria RDT uptake and adherence. BMJ Open 2017; 7:e012973. [PMID: 28274962 PMCID: PMC5353269 DOI: 10.1136/bmjopen-2016-012973] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES The overuse of antimalarial drugs is widespread. Effective methods to improve prescribing practice remain unclear. We evaluated the impact of 10 interventions that introduced rapid diagnostic tests for malaria (mRDTs) on the use of tests and adherence to results in different contexts. DESIGN A comparative case study approach, analysing variation in outcomes across different settings. SETTING Studies from the ACT Consortium evaluating mRDTs with a range of supporting interventions in 6 malaria endemic countries. Providers were governmental or non-governmental healthcare workers, private retail sector workers or community volunteers. Each study arm in a distinct setting was considered a case. PARTICIPANTS 28 cases from 10 studies were included, representing 148 461 patients seeking care for suspected malaria. INTERVENTIONS The interventions included different mRDT training packages, supervision, supplies and community sensitisation. OUTCOME MEASURES Analysis explored variation in: (1) uptake of mRDTs (% febrile patients tested); (2) provider adherence to positive mRDTs (% Plasmodium falciparum positive prescribed/given Artemisinin Combination Treatment); (3) provider adherence to negative mRDTs (% P. falciparum negative not prescribed/given antimalarial). RESULTS Outcomes varied widely across cases: 12-100% mRDT uptake; 44-98% adherence to positive mRDTs; 27-100% adherence to negative mRDTs. Providers appeared more motivated to perform well when mRDTs and intervention characteristics fitted with their own priorities. Goodness of fit of mRDTs with existing consultation and diagnostic practices appeared crucial to maximising the impact of mRDTs on care, as did prior familiarity with malaria testing; adequate human resources and supplies; possible alternative treatments for mRDT-negative patients; a more directive intervention approach and local preferences for ACTs. CONCLUSIONS Basic training and resources are essential but insufficient to maximise the potential of mRDTs in many contexts. Programme design should respond to assessments of provider priorities, expectations and capacities. As mRDTs become established, the intensity of supporting interventions required seems likely to reduce.
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Affiliation(s)
- Helen E D Burchett
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Baptiste Leurent
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Frank Baiden
- Epidemiology Unit, Ensign College of Public Health, Kpong, Ghana
| | - Kimberly Baltzell
- Department of Family Health Care Nursing, and Global Health Science, University of California, Berkeley, California, USA
| | - Anders Björkman
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Katia Bruxvoort
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Siân Clarke
- Disease Control Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Deborah DiLiberto
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Kristina Elfving
- Department of Infectious Diseases, Sahlgrenska Academy, University of Gothenburg, Goteborg, Sweden
- Department of Paediatrics, Sahlgrenska Academy, University of Gothenburg, Goteborg, Sweden
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Catherine Goodman
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Heidi Hopkins
- Disease Control Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Sham Lal
- Disease Control Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Marco Liverani
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Pascal Magnussen
- Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Mårtensson
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Wilfred Mbacham
- Laboratory for Public Health Research Biotechnologies, The Biotechnology Center, University of Yaoundé, Yaoundé, Cameroon
| | - Anthony Mbonye
- School of Public Health- Makerere University and Commissioner Health Services, Ministry of Health, Uganda
| | - Obinna Onwujekwe
- Department of Pharmacology and Therapeutics, University of Nigeria Enugu-Campus, Nigeria
| | | | - Delér Shakely
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institute, Stockholm, Sweden
- Department of Medicine, Kungälv Hospital, Sweden
| | - Sarah Staedke
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Lasse S Vestergaard
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital Rigshospitalet, Denmark
- Department of Infectious Disease Epidemiology, Statens Serum Institut, Denmark
| | - Christopher J M Whitty
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Virginia Wiseman
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
- School of Public Health and Community Medicine, Australia
| | - Clare I R Chandler
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
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Kemleu S, Guelig D, Eboumbou Moukoko C, Essangui E, Diesburg S, Mouliom A, Melingui B, Manga J, Donkeu C, Epote A, Texier G, LaBarre P, Burton R, Ayong L. A Field-Tailored Reverse Transcription Loop-Mediated Isothermal Assay for High Sensitivity Detection of Plasmodium falciparum Infections. PLoS One 2016; 11:e0165506. [PMID: 27824866 PMCID: PMC5100904 DOI: 10.1371/journal.pone.0165506] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/13/2016] [Indexed: 11/19/2022] Open
Abstract
Highly sensitive and field deployable molecular diagnostic tools are critically needed for detecting submicroscopic, yet transmissible levels of malaria parasites prevalent in malaria endemic countries worldwide. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed and evaluated in comparison with thick blood smear microscopy, an antigen-based rapid diagnostic test (RDT), and an in-house RT-PCR targeting the same RT-LAMP transcript. The optimized assay detected Plasmodium falciparum infections in as little as 0.25ng of total parasite RNA, and exhibited a detection limit of 0.08 parasites/ μL when tested directly on infected whole blood lysates, or ~0.0008 parasites/ μL when using RNA extracts. Assay positivity was observed as early as eight minutes from initiation of the RT-LAMP and in most cases the reaction was complete before twenty minutes. Clinical evaluation of the assay on 132 suspected malaria cases resulted in a positivity rate of 90% for RT-LAMP using extracted RNA, and 85% when using whole blood lysates. The positivity rates were 70% for P. falciparum-specific RDT, 83% for RT-PCR, and 74% for thick blood smear microscopy (Mean parasite density = 36,986 parasites/ μL). Concordance rates between the developed RT-LAMP and comparator tests were greater than 75%, the lowest being with light microscopy (78%, McNemar's test: P = 0.0002), and the highest was with RT-PCR (87%, McNemar's test: P = 0.0523). Compared to reference RT-PCR, assay sensitivity was 90% for RT-LAMP on whole blood, and 96% for RT-LAMP using corresponding RNA extracts. Electricity-free heaters were further developed and evaluated in comparison with a battery-operated isothermal amplification machine for use with the developed test in resource-limited settings. Taken together, the data highlight the benefits of targeting high abundant RNA transcripts in molecular diagnosis, as well as the potential usefulness of the developed RT-LAMP-assay in malaria diagnosis in low to high parasite density settings.
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Affiliation(s)
- Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Dylan Guelig
- PATH, Seattle, Washington, United States of America
| | - Carole Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | | | - Abas Mouliom
- Hematology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | | | - Jeanne Manga
- Hematology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Annie Epote
- Hematology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Gaëtan Texier
- Public Health & Epidemiology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Paul LaBarre
- PATH, Seattle, Washington, United States of America
| | | | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- * E-mail:
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29
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Ndyomugyenyi R, Magnussen P, Lal S, Hansen K, Clarke SE. Appropriate targeting of artemisinin-based combination therapy by community health workers using malaria rapid diagnostic tests: findings from randomized trials in two contrasting areas of high and low malaria transmission in south-western Uganda. Trop Med Int Health 2016; 21:1157-70. [PMID: 27383558 PMCID: PMC5031222 DOI: 10.1111/tmi.12748] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Objective To compare the impact of malaria rapid diagnostic tests (mRDTs), used by community health workers (CHWs), on the proportion of children <5 years of age receiving appropriately targeted treatment with artemisinin‐based combination therapy (ACT), vs. presumptive treatment. Methods Cluster‐randomized trials were conducted in two contrasting areas of moderate‐to‐high and low malaria transmission in rural Uganda. Each trial examined the effectiveness of mRDTs in the management of malaria and targeting of ACTs by CHWs comparing two diagnostic approaches: (i) presumptive clinical diagnosis of malaria [control arm] and (ii) confirmatory diagnosis with mRDTs followed by ACT treatment for positive patients [intervention arm], with village as the unit of randomisation. Treatment decisions by CHWs were validated by microscopy on a reference blood slide collected at the time of consultation, to compare the proportion of children <5 years receiving appropriately targeted ACT treatment, defined as patients with microscopically‐confirmed presence of parasites in a peripheral blood smear receiving artemether‐lumefantrine or rectal artesunate, and patients with no malaria parasites not given ACT. Results In the moderate‐to‐high transmission area, ACT treatment was appropriately targeted in 79.3% (520/656) of children seen by CHWs using mRDTs to diagnose malaria, vs. 30.8% (215/699) of children seen by CHWs using presumptive diagnosis (P < 0.001). In the low transmission area, 90.1% (363/403) children seen by CHWs using mRDTs received appropriately targeted ACT treatment vs. 7.8% (64/817) seen by CHWs using presumptive diagnosis (P < 0.001). Low mRDT sensitivity in children with low‐density parasitaemia (<200 parasites/μl) was identified as a potential concern. Conclusion When equipped with mRDTs, ACT treatments delivered by CHWs are more accurately targeted to children with malaria parasites. mRDT use could play an important role in reducing overdiagnosis of malaria and improving fever case management within iCCM, in both moderate‐to‐high and low transmission areas. Nonetheless, missed treatments due to the low sensitivity of current mRDTs in patients with low parasite density are a concern. For community‐based treatment in areas of low transmission and/or non‐immune populations, presumptive treatment of all fevers as malaria may be advisable, until more sensitive diagnostic assays, suitable for routine use by CHWs in remote settings, become available.
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Affiliation(s)
| | - Pascal Magnussen
- Centre for Medical Parasitology, Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sham Lal
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Kristian Hansen
- Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Siân E Clarke
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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30
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Johansson EW, Selling KE, Nsona H, Mappin B, Gething PW, Petzold M, Peterson SS, Hildenwall H. Integrated paediatric fever management and antibiotic over-treatment in Malawi health facilities: data mining a national facility census. Malar J 2016; 15:396. [PMID: 27488343 PMCID: PMC4972956 DOI: 10.1186/s12936-016-1439-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/11/2016] [Indexed: 11/16/2022] Open
Abstract
Background There are growing concerns about irrational antibiotic prescription practices in the era of test-based malaria case management. This study assessed integrated paediatric fever management using malaria rapid diagnostic tests (RDT) and Integrated Management of Childhood Illness (IMCI) guidelines, including the relationship between RDT-negative results and antibiotic over-treatment in Malawi health facilities in 2013–2014. Methods A Malawi national facility census included 1981 observed sick children aged 2–59 months with fever complaints. Weighted frequencies were tabulated for other complaints, assessments and prescriptions for RDT-confirmed malaria, IMCI-classified non-severe pneumonia, and clinical diarrhoea. Classification trees using model-based recursive partitioning estimated the association between RDT results and antibiotic over-treatment and learned the influence of 38 other input variables at patient-, provider- and facility-levels. Results Among 1981 clients, 72 % were tested or referred for malaria diagnosis and 85 % with RDT-confirmed malaria were prescribed first-line anti-malarials. Twenty-eight percent with IMCI-pneumonia were not prescribed antibiotics (under-treatment) and 59 % ‘without antibiotic need’ were prescribed antibiotics (over-treatment). Few clients had respiratory rates counted to identify antibiotic need for IMCI-pneumonia (18 %). RDT-negative children had 16.8 (95 % CI 8.6–32.7) times higher antibiotic over-treatment odds compared to RDT-positive cases conditioned by cough or difficult breathing complaints. Conclusions Integrated paediatric fever management was sub-optimal for completed assessments and antibiotic targeting despite common compliance to malaria treatment guidelines. RDT-negative results were strongly associated with antibiotic over-treatment conditioned by cough or difficult breathing complaints. A shift from malaria-focused ‘test and treat’ strategies toward ‘IMCI with testing’ is needed to improve quality fever care and rational use of both anti-malarials and antibiotics in line with recent global commitments to combat resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1439-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Emily White Johansson
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden.
| | - Katarina Ekholm Selling
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
| | - Humphreys Nsona
- Integrated Management of Childhood Illness (IMCI) Unit, Ministry of Health, Lilongwe, Malawi
| | - Bonnie Mappin
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, UK
| | - Peter W Gething
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, UK
| | - Max Petzold
- The Sahlgrenska Academy, Center for Applied Biostatistics, University of Gothenburg, Gothenburg, Sweden
| | - Stefan Swartling Peterson
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden.,Global Health-Health Systems and Policy Research Group, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.,School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Helena Hildenwall
- Global Health-Health Systems and Policy Research Group, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
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31
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Performance of rapid diagnostic test, blood-film microscopy and PCR for the diagnosis of malaria infection among febrile children from Korogwe District, Tanzania. Malar J 2016; 15:391. [PMID: 27459856 PMCID: PMC4962396 DOI: 10.1186/s12936-016-1450-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/20/2016] [Indexed: 11/10/2022] Open
Abstract
Background Rapid diagnostic tests (RDT) and light microscopy are still recommended for diagnosis to guide the clinical management of malaria despite difficult challenges in rural settings. The performance of these tests may be affected by several factors, including malaria prevalence and intensity of transmission. The study evaluated the diagnostic performance of malaria RDT, light microscopy and polymerase chain reaction (PCR) in detecting malaria infections among febrile children at outpatient clinic in Korogwe District, northeastern Tanzania. Methods The study enrolled children aged 2–59 months with fever and/or history of fever in the previous 48 h attending outpatient clinics. Blood samples were collected for identification of Plasmodium falciparum infection using histidine-rich-protein-2 (HRP-2)-based malaria RDT, light microscopy and conventional PCR. Results A total of 867 febrile patients were enrolled into the study. Malaria-positive samples were 85/867 (9.8 %, 95 % CI, 7.9–12.0 %) by RDT, 72/867 (8.3 %, 95 % CI, 6.5–10.1 %) by microscopy and 79/677 (11.7 %, 95 % CI, 9.3–14.3 %) by PCR. The performance of malaria RDT compared with microscopy results had sensitivity and positive predictive value (PPV) of 88.9 % (95 % CI, 79.3–95.1 %) and 75.3 % (95 % CI, 64.8–84.0 %), respectively. Confirmation of P. falciparum infection with PCR analysis provided lower sensitivity and PPV of 88.6 % (95 % CI, 79.5–94.7 %) and 84.3 % (95 % CI, 74.7–91.4 %) for RDT compared to microscopy. Conclusion Diagnosis of malaria infection is still a challenge due to variation in results among diagnostic methods. HRP-2 malaria RDT and microscopy were less sensitive than PCR. Diagnostic tools with high sensitivity are required in areas of low malaria transmission.
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32
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Kabaghe AN, Visser BJ, Spijker R, Phiri KS, Grobusch MP, van Vugt M. Health workers' compliance to rapid diagnostic tests (RDTs) to guide malaria treatment: a systematic review and meta-analysis. Malar J 2016; 15:163. [PMID: 26979286 PMCID: PMC4791859 DOI: 10.1186/s12936-016-1218-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/05/2016] [Indexed: 11/23/2022] Open
Abstract
Background The World Health Organization recommends malaria to be confirmed by either microscopy or a rapid diagnostic test (RDT) before treatment. The correct use of RDTs in resource-limited settings facilitates basing treatment onto a confirmed diagnosis; contributes to speeding up considering a correct alternative diagnosis, and prevents overprescription of anti-malarial drugs, reduces costs and avoids unnecessary exposure to adverse drug effects. This review aims to evaluate health workers’ compliance to RDT results and factors contributing to compliance. Methods A PROSPERO-registered systematic review was conducted to evaluate health workers’ compliance to RDTs in sub-Saharan Africa, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies published up to November 2015 were searched without language restrictions in Medline/Ovid, Embase, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, Biosis Previews and the African Index Medicus. The primary outcome was health workers treating patients according to the RDT results obtained. Results The literature search identified 474 reports; 14 studies were eligible and included in the quantitative analysis. From the meta-analysis, health workers’ overall compliance in terms of initiating treatment or not in accordance with the respective RDT results was 83 % (95 % CI 80–86 %). Compliance to positive and negative results was 97 % (95 % CI 94–99 %) and 78 % (95 % CI 66–89 %), respectively. Community health workers had higher compliance rates to negative test results than clinicians. Patient expectations, work experience, scepticism of results, health workers’ cadres and perceived effectiveness of the test, influenced compliance. Conclusions With regard to published data, compliance to RDT appears to be generally fair in sub-Saharan Africa; compliance to negative results will need to improve to prevent mismanagement of patients and overprescribing of anti-malarial drugs. Improving diagnostic capacity for other febrile illnesses and developing local evidence-based guidelines may help improve compliance and management of negative RDT results. Trial registration: CRD42015016151 (PROSPERO) Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1218-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alinune N Kabaghe
- Public Health Department, College of Medicine, Private Bag 360, Blantyre, Malawi.,Division of Internal Medicine, Department of Infectious Diseases, Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Benjamin J Visser
- Division of Internal Medicine, Department of Infectious Diseases, Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Centre de Recherches de Médicales de Lambaréné (CERMEL), Albert Schweitzer Hospital, Lambaréné, Gabon.
| | - Rene Spijker
- Medical Library, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Cochrane Netherlands, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kamija S Phiri
- Public Health Department, College of Medicine, Private Bag 360, Blantyre, Malawi
| | - Martin P Grobusch
- Division of Internal Medicine, Department of Infectious Diseases, Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.,Centre de Recherches de Médicales de Lambaréné (CERMEL), Albert Schweitzer Hospital, Lambaréné, Gabon
| | - Michèle van Vugt
- Division of Internal Medicine, Department of Infectious Diseases, Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
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Elfving K, Shakely D, Andersson M, Baltzell K, Ali AS, Bachelard M, Falk KI, Ljung A, Msellem MI, Omar RS, Parola P, Xu W, Petzold M, Trollfors B, Björkman A, Lindh M, Mårtensson A. Acute Uncomplicated Febrile Illness in Children Aged 2-59 months in Zanzibar - Aetiologies, Antibiotic Treatment and Outcome. PLoS One 2016; 11:e0146054. [PMID: 26821179 PMCID: PMC4731140 DOI: 10.1371/journal.pone.0146054] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/11/2015] [Indexed: 12/29/2022] Open
Abstract
Background Despite the fact that a large proportion of children with fever in Africa present at primary health care facilities, few studies have been designed to specifically study the causes of uncomplicated childhood febrile illness at this level of care, especially in areas like Zanzibar that has recently undergone a dramatic change from high to low malaria transmission. Methods We prospectively studied the aetiology of febrile illness in 677 children aged 2–59 months with acute uncomplicated fever managed by IMCI (Integrated Management of Childhood Illness) guidelines in Zanzibar, using point-of-care tests, urine culture, blood-PCR, chest X-ray (CXR) of IMCI-pneumonia classified patients, and multiple quantitative (q)PCR investigations of nasopharyngeal (NPH) (all patients) and rectal (GE) swabs (diarrhoea patients). For comparison, we also performed NPH and GE qPCR analyses in 167 healthy community controls. Final fever diagnoses were retrospectively established based on all clinical and laboratory data. Clinical outcome was assessed during a 14-day follow-up. The utility of IMCI for identifying infections presumed to require antibiotics was evaluated. Findings NPH-qPCR and GE-qPCR detected ≥1 pathogen in 657/672 (98%) and 153/164 (93%) of patients and 158/166 (95%) and 144/165 (87%) of controls, respectively. Overall, 57% (387/677) had IMCI-pneumonia, but only 12% (42/342) had CXR-confirmed pneumonia. Two patients were positive for Plasmodium falciparum. Respiratory syncytial virus (24.5%), influenza A/B (22.3%), rhinovirus (10.5%) and group-A streptococci (6.4%), CXR-confirmed pneumonia (6.2%), Shigella (4.3%) were the most common viral and bacterial fever diagnoses, respectively. Blood-PCR conducted in a sub-group of patients (n = 83) without defined fever diagnosis was negative for rickettsiae, chikungunya, dengue, Rift Valley fever and West Nile viruses. Antibiotics were prescribed to 500 (74%) patients, but only 152 (22%) had an infection retrospectively considered to require antibiotics. Clinical outcome was generally good. However, two children died. Only 68 (11%) patients remained febrile on day 3 and three of them had verified fever on day 14. An additional 29 (4.5%) children had fever relapse on day 14. Regression analysis determined C-reactive Protein (CRP) as the only independent variable significantly associated with CXR-confirmed pneumonia. Conclusions This is the first study on uncomplicated febrile illness in African children that both applied a comprehensive laboratory panel and a healthy control group. A majority of patients had viral respiratory tract infection. Pathogens were frequently detected by qPCR also in asymptomatic children, demonstrating the importance of incorporating controls in fever aetiology studies. The precision of IMCI for identifying infections requiring antibiotics was low.
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Affiliation(s)
- Kristina Elfving
- Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
- Department of Paediatrics, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
| | - Deler Shakely
- Malaria Research, Department of Microbiology, Tumour and Cell biology, Karolinska Institutet, Stockholm, Sweden
- Department of Medicine, Kungälv Hospital, Kungälv, Sweden
| | - Maria Andersson
- Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
| | - Kimberly Baltzell
- Department of Family Health Care Nursing, University of California San Francisco, San Francisco, United States of America
| | - Abdullah S. Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Marc Bachelard
- Department of Paediatrics, University of Gothenburg, Gothenburg, Sweden
| | - Kerstin I. Falk
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Annika Ljung
- Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
| | - Mwinyi I. Msellem
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Rahila S. Omar
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Philippe Parola
- Aix Marseille University, UM63, WHO collaborative centre for rickettsioses and other arthropod borne bacterial diseases, Faculté de Médecine, Marseille, France
| | - Weiping Xu
- Malaria Research, Department of Microbiology, Tumour and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Max Petzold
- Akademistatistik, Centre for Applied Biostatistics, Occupational and Environmental Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Birger Trollfors
- Department of Paediatrics, University of Gothenburg, Gothenburg, Sweden
| | - Anders Björkman
- Malaria Research, Department of Microbiology, Tumour and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Magnus Lindh
- Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
| | - Andreas Mårtensson
- Malaria Research, Department of Microbiology, Tumour and Cell biology, Karolinska Institutet, Stockholm, Sweden
- Centre for Clinical Research Sörmland, Uppsala University, Uppsala, Sweden
- Department of Women’s and Children’s Health, International Maternal and Child Health Unit (IMCH), Uppsala University, Uppsala, Sweden
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Mendelson M, Røttingen JA, Gopinathan U, Hamer DH, Wertheim H, Basnyat B, Butler C, Tomson G, Balasegaram M. Maximising access to achieve appropriate human antimicrobial use in low-income and middle-income countries. Lancet 2016; 387:188-98. [PMID: 26603919 DOI: 10.1016/s0140-6736(15)00547-4] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Access to quality-assured antimicrobials is regarded as part of the human right to health, yet universal access is often undermined in low-income and middle-income countries. Lack of access to the instruments necessary to make the correct diagnosis and prescribe antimicrobials appropriately, in addition to weak health systems, heightens the challenge faced by prescribers. Evidence-based interventions in community and health-care settings can increase access to appropriately prescribed antimicrobials. The key global enablers of sustainable financing, governance, and leadership will be necessary to achieve access while preventing excess antimicrobial use.
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Affiliation(s)
- Marc Mendelson
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa.
| | - John-Arne Røttingen
- Norwegian Institute of Public Health, Oslo, Norway; Institute of Health and Society, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Global Health and Population, Harvard T H Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Unni Gopinathan
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Davidson H Hamer
- Zambia Center for Applied Health Research and Development, Lusaka, Zambia; Center for Global Health and Development, Boston University School of Public Health, Boston, MA, USA; Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Heiman Wertheim
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, National Hospital for Tropical Diseases, Hanoi, Vietnam; Nuffield Department of Clinical Medicine, Centre for Tropical Diseases, Oxford, UK
| | - Buddha Basnyat
- Oxford University Clinical Research Unit-Nepal, Kathmandu, Nepal
| | - Christopher Butler
- Nuffield Department of Primary Care Health Sciences, Oxford University, Oxford, UK
| | - Göran Tomson
- Departments of Learning, Informatics, Management, Ethics and Public Health Sciences, Karolinska Institute, Stockholm, Sweden
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Doctor SM, Liu Y, Whitesell A, Thwai KL, Taylor SM, Janko M, Emch M, Kashamuka M, Muwonga J, Tshefu A, Meshnick SR. Malaria surveillance in the Democratic Republic of the Congo: comparison of microscopy, PCR, and rapid diagnostic test. Diagn Microbiol Infect Dis 2016; 85:16-8. [PMID: 26915637 DOI: 10.1016/j.diagmicrobio.2016.01.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/10/2015] [Accepted: 01/07/2016] [Indexed: 10/22/2022]
Abstract
Malaria surveillance is critical for control efforts, but diagnostic methods frequently disagree. Here, we compare microscopy, PCR, and a rapid diagnostic test in 7137 samples from children in the Democratic Republic of the Congo using latent class analysis. PCR had the highest sensitivity (94.6%) and microscopy had the lowest (76.7%).
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Affiliation(s)
- Stephanie M Doctor
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Yunhao Liu
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Statistics and Operations Research, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Amy Whitesell
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kyaw L Thwai
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Steve M Taylor
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27708, USA
| | - Mark Janko
- Department of Geography, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Population Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Michael Emch
- Department of Geography, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Population Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Melchior Kashamuka
- Ecole de Santé Publique, Faculté de Medecine, Université de Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Jérémie Muwonga
- Programme National de Lutte contre le SIDA et les IST, Kinshasa, Democratic Republic of the Congo
| | - Antoinette Tshefu
- Ecole de Santé Publique, Faculté de Medecine, Université de Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA
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Haji KA, Thawer NG, Khatib BO, Mcha JH, Rashid A, Ali AS, Jones C, Bagi J, Magesa SM, Ramsan MM, Garimo I, Greer G, Reithinger R, Ngondi JM. Efficacy, persistence and vector susceptibility to pirimiphos-methyl (Actellic 300CS) insecticide for indoor residual spraying in Zanzibar. Parasit Vectors 2015; 8:628. [PMID: 26652708 PMCID: PMC4674920 DOI: 10.1186/s13071-015-1239-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/03/2015] [Indexed: 11/10/2022] Open
Abstract
Background Indoor residual spraying (IRS) of households with insecticide is a principal malaria vector control intervention in Zanzibar. In 2006, IRS using the pyrethroid lambda-cyhalothrine was introduced in Zanzibar. Following detection of pyrethroid resistance in 2010, an insecticide resistance management plan was proposed, and IRS using bendiocarb was started in 2011. In 2014, bendiocarb was replaced by pirimiphos methyl. This study investigated the residual efficacy of pirimiphos methyl (Actellic® 300CS) sprayed on common surfaces of human dwellings in Zanzibar. Methods The residual activity of Actellic 300CS was determined over 9 months through bioassay tests that measured the mortality of female Anopheles mosquitoes, exposed to sprayed surfaces under a WHO cone. The wall surfaces included; mud wall, oil or water painted walls, lime washed wall, un-plastered cement block wall and stone blocks. Insecticide susceptibility testing was done to investigate the resistance status of local malaria vectors against Actellic 300CS using WHO protocols; Anopheline species were identified using PCR methods. Results Baseline tests conducted one-day post-IRS revealed 100 % mortality on all sprayed surfaces. The residual efficacy of Actellic 300CS was maintained on all sprayed surfaces up to 8 months post-IRS. However, the bioassay test conducted 9 months post-IRS showed the 24 h mortality rate to be ≤80 % for lime wash, mud wall, water paint and stone block surfaces. Only oil paint surface retained the recommended residual efficacy beyond 9 months post-IRS, with mortality maintained at ≥97 %. Results of susceptibility tests showed that malaria vectors in Zanzibar were fully (100 %) susceptible to Actellic 300CS. The predominant mosquito vector species was An. arabiensis (76.0 %) in Pemba and An. gambiae (83.5 %) in Unguja. Conclusion The microencapsulated formulation of pirimiphos methyl (Actellic 300CS) is a highly effective and appropriate insecticide for IRS use in Zanzibar as it showed a relatively prolonged residual activity compared to other products used for the same purpose. The insecticide extends the residual effect of IRS thereby making it possible to effectively protect communities with a single annual spray round reducing overall costs. The insecticide proved to be a useful alternative in insecticide resistance management plans.
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Affiliation(s)
- Khamis A Haji
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania.
| | | | | | - Juma H Mcha
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania.
| | | | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania.
| | | | - Judit Bagi
- Liverpool School of Tropical Medicine, Liverpool, UK.
| | | | | | | | - George Greer
- President's Malaria Initiative/United States Agency for International Development, Dar es Salaam, Tanzania.
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Alidina Z, Colaco R, Ali AS, Mcha JH, Mwalimu CD, Thawer NG, Lalji S, Mutagahywa J, Ramsan MM, Kafuko JM, Kaspar N, Magesa SM, Reithinger R, Ngondi JM. Taking local ownership: government and household contribution to indoor residual spraying in Zanzibar and mainland Tanzania. Int Health 2015; 8:299-306. [PMID: 26612853 DOI: 10.1093/inthealth/ihv066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/05/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND While donor funding is instrumental in initiation and implementation of malaria control efforts, national government contributions are key to local ownership and sustainability. This study explored in-kind contributions of local government and households towards the cost of indoor residual spraying (IRS) interventions in Tanzania. METHODS Data were collected through interviews with local government officials and technical teams in the IRS project. Household contribution was based on provision of water for IRS. Government contributions included government-provided warehouse and office space, vehicles, and staff labour. In-kind contributions were aggregated at the district, regional and national level. Calculations were based on proportion of total costs of IRS from 2010 to 2012. RESULTS The mainland government provided larger amounts of in-kind contribution in absolute value (mean of US$454 200) compared to Zanzibar (US$89 163). On average, in-kind contribution was 5.5% of total costs in Zanzibar and 2.9% in mainland. The proportion of government in-kind contribution was higher in Zanzibar versus the mainland (86% vs 50%) while household contribution was higher in mainland compared to Zanzibar (50% vs 14%). CONCLUSION Government involvement, particularly through budgetary allocations and increased in-kind contribution, needs to be encouraged for malaria control efforts to be locally owned, managed and sustained.
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Affiliation(s)
| | | | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - Juma H Mcha
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - Charles D Mwalimu
- National Malaria Control Program, Ministry of Health and Social Welfare, Dar es Salaam, Tanzania
| | | | | | | | | | - Jessica M Kafuko
- United States Agency for International Development/President's Malaria Initiative, Abuja, Nigeria
| | - Naomi Kaspar
- United States Agency for International Development/President's Malaria Initiative, Dar es Salaam, Tanzania
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Ndhlovu M, Nkhama E, Miller JM, Hamer DH. Antibiotic prescribing practices for patients with fever in the transition from presumptive treatment of malaria to 'confirm and treat' in Zambia: a cross-sectional study. Trop Med Int Health 2015; 20:1696-706. [PMID: 26311240 DOI: 10.1111/tmi.12591] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To evaluate antibiotic use among patients presenting to primary healthcare facilities with febrile illness in Zambia. METHODS We analysed data from a 2011 nationwide cross-sectional health facility survey of routine malaria case management in Zambia. Patient consultation observation and medical record charts were used to calculate the proportion of febrile patients who were prescribed antibiotics, stratified by symptoms, health workers' diagnosis and malaria test results. Logistic regression was used to identify factors affecting antibiotic prescribing behaviour. RESULTS Of 872 patients presenting with fever, 651 (74.6%) were tested for malaria. Among those tested, 608 (93.4%) had analysable results; 230 (37.8%) had positive results. Antibiotics were prescribed to 69/230 (30.0%), 247/378 (65.3%) and 132/221 (59.7%) of those who tested positive, negative and those 'not tested', respectively. Furthermore, antibiotics were prescribed to 36/59 (61.0%) and 242/322 (75.1%) of those diagnosed with diarrhoea and upper respiratory tract infection (URTI), respectively. Among patients prescribed any antibiotic, concurrent antimalarial prescribing occurred in 66/69 (95.6%), 32/247 (12.9%) and 19/132 (14.4%) for those with positive results, negative results and 'not tested', respectively. Respiratory symptoms, diagnosis of URTI, malaria or skin disease and level of health care in the health delivery system were associated with antibiotic prescribing. CONCLUSIONS Testing positive for malaria or receiving a malaria diagnosis was associated with reduced antibiotic prescribing, while testing negative, not being tested or a diagnosis of URTI resulted in higher rates of antibiotic prescribing. There is a need for improving diagnostic capacity for non-malaria causes of febrile illness at healthcare delivery points and limiting antibiotic use to patients with definite bacterial infections.
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Affiliation(s)
| | - Emmy Nkhama
- Chainama College of Health Sciences, Lusaka, Zambia
| | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa, National Malaria Control Centre, Lusaka, Zambia
| | - Davidson H Hamer
- Zambia Center for Applied Health Research & Development, Lusaka, Zambia.,Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA.,Department of Global Health, Boston University School of Public Health, Boston, MA, USA.,Section of Infectious Diseases, Boston University School of Medicine, Boston, MA, USA
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Tseroni M, Pervanidou D, Tserkezou P, Rachiotis G, Pinaka O, Baka A, Georgakopoulou T, Vakali A, Dionysopoulou M, Terzaki I, Marka A, Detsis M, Evlampidou Z, Mpimpa A, Vassalou E, Tsiodras S, Tsakris A, Kremastinou J, Hadjichristodoulou C. Field application of SD bioline malaria Ag Pf/Pan rapid diagnostic test for malaria in Greece. PLoS One 2015; 10:e0120367. [PMID: 25803815 PMCID: PMC4372373 DOI: 10.1371/journal.pone.0120367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/09/2015] [Indexed: 11/18/2022] Open
Abstract
Greece, a malaria-free country since 1974, has experienced re-emergence of Plasmodium vivax autochthonous malaria cases in some agriculture areas over the last three years. In early 2012, an integrated control programme (MALWEST Project) was launched in order to prevent re-establishment of the disease. In the context of this project, the rapid diagnostic tests (RDT) of SD Bioline Malaria Ag Pf/Pan that detects hrp-2 and pan-LDH antigens were used. The aim of this study was to assess the field application of the RDT for the P. vivax diagnosis in comparison to light microscopy and polymerase chain reaction (PCR). A total of 955 samples were tested with all three diagnostic tools. Agreement of RDT against microscopy and PCR for the diagnosis of P. vivax was satisfactory (K value: 0.849 and 0.976, respectively). The sensitivity, specificity and positive predictive value of RDT against PCR was 95.6% (95% C.I.: 84.8-99.3), 100% (95% C.I.: 99.6-100.0) and 100% (95% CI: 91.7-100.0) respectively, while the sensitivity, specificity and positive predictive value of RDT against microscopic examination was 97.4% (95% C.I.: 86.1-99.6), 99.4% (95% C.I.: 98.6-99.8) and 86.1% (95% CI: 72.1-94.7), respectively. Our results indicate that RDT performed satisfactory in a non-endemic country and therefore is recommended for malaria diagnosis, especially in areas where health professionals lack experience on light microscopy.
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Affiliation(s)
- Maria Tseroni
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | - Danai Pervanidou
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | - Persefoni Tserkezou
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - George Rachiotis
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Ourania Pinaka
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Agoritsa Baka
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | | | - Annita Vakali
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | | | - Irene Terzaki
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | - Andriani Marka
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Marios Detsis
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | | | - Anastasia Mpimpa
- Department of Parasitology, Entomology and Tropical Diseases, National School of Public Health, Athens, Greece
| | - Evdokia Vassalou
- Department of Parasitology, Entomology and Tropical Diseases, National School of Public Health, Athens, Greece
| | - Sotirios Tsiodras
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | - Athanasios Tsakris
- Department of Microbiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Jenny Kremastinou
- Hellenic Centre for Disease Control & Prevention (KEELPNO), Athens, Greece
| | - Christos Hadjichristodoulou
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
- * E-mail:
| | - MALWEST Project
- Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
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SYBR Green real-time PCR-RFLP assay targeting the plasmodium cytochrome B gene--a highly sensitive molecular tool for malaria parasite detection and species determination. PLoS One 2015; 10:e0120210. [PMID: 25774805 PMCID: PMC4361616 DOI: 10.1371/journal.pone.0120210] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/20/2015] [Indexed: 11/19/2022] Open
Abstract
A prerequisite for reliable detection of low-density Plasmodium infections in malaria pre-elimination settings is the availability of ultra-sensitive and high-throughput molecular tools. We developed a SYBR Green real-time PCR restriction fragment length polymorphism assay (cytb-qPCR) targeting the cytochrome b gene of the four major human Plasmodium species (P. falciparum, P. vivax, P. malariae, and P. ovale) for parasite detection and species determination with DNA extracted from dried blood spots collected on filter paper. The performance of cytb-qPCR was first compared against four reference PCR methods using serially diluted Plasmodium samples. The detection limit of the cytb-qPCR was 1 parasite/μl (p/μl) for P. falciparum and P. ovale, and 2 p/μl for P. vivax and P. malariae, while the reference PCRs had detection limits of 0.5-10 p/μl. The ability of the PCR methods to detect low-density Plasmodium infections was then assessed using 2977 filter paper samples collected during a cross-sectional survey in Zanzibar, a malaria pre-elimination setting in sub-Saharan Africa. Field samples were defined as 'final positive' if positive in at least two of the five PCR methods. Cytb-qPCR preformed equal to or better than the reference PCRs with a sensitivity of 100% (65/65; 95%CI 94.5-100%) and a specificity of 99.9% (2910/2912; 95%CI 99.7-100%) when compared against 'final positive' samples. The results indicate that the cytb-qPCR may represent an opportunity for improved molecular surveillance of low-density Plasmodium infections in malaria pre-elimination settings.
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Loop-mediated isothermal amplification (LAMP) for point-of-care detection of asymptomatic low-density malaria parasite carriers in Zanzibar. Malar J 2015; 14:43. [PMID: 25627037 PMCID: PMC4318361 DOI: 10.1186/s12936-015-0573-y] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/18/2015] [Indexed: 01/12/2023] Open
Abstract
Background Asymptomatic, low parasite density malaria infections are difficult to detect with currently available point-of-care diagnostics. This study piloted a loop-mediated isothermal amplification (LAMP) kit for field-friendly, high-throughput detection of asymptomatic malaria infections during mass screening and treatment (MSAT) in Zanzibar, a malaria pre-elimination setting. Methods Screening took place in three known hotspot areas prior to the short rains in November. Finger-prick blood was taken for screening by rapid diagnostic test (RDT) and LAMP and collected on filter paper for subsequent polymerase chain reaction (PCR) analyses. LAMP results were compared to RDT and to PCR using McNemar’s test. Results Approximately 1,000 people were screened. RDT detected ten infections (1.0% (95% CI 0.3-1.6)) whilst both LAMP and PCR detected 18 (1.8% (95% CI 0.9-2.6)) infections. However, PCR identified three infections that LAMP did not detect and vice versa. LAMP testing was easy to scale-up in field conditions requiring minimal training and equipment, with results ready one to three hours after screening. Conclusions Despite lower than expected prevalence, LAMP detected a higher number of infections than the currently used diagnostic, RDT. LAMP is a field-friendly, sensitive diagnostic test that could be useful for MSAT malaria campaigns which require quick results to enable prompt treatment.
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Laban NM, Kobayashi T, Hamapumbu H, Sullivan D, Mharakurwa S, Thuma PE, Shiff CJ, Moss WJ. Comparison of a PfHRP2-based rapid diagnostic test and PCR for malaria in a low prevalence setting in rural southern Zambia: implications for elimination. Malar J 2015; 14:25. [PMID: 25888818 PMCID: PMC4340619 DOI: 10.1186/s12936-015-0544-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 01/05/2015] [Indexed: 12/01/2022] Open
Abstract
Background Rapid diagnostic tests (RDTs) detecting histidine-rich protein 2 (PfHRP2) antigen are used to identify individuals with Plasmodium falciparum infection even in low transmission settings seeking to achieve elimination. However, these RDTs lack sensitivity to detect low-density infections, produce false negatives for P. falciparum strains lacking pfhrp2 gene and do not detect species other than P. falciparum. Methods Results of a PfHRP2-based RDT and Plasmodium nested PCR were compared in a region of declining malaria transmission in southern Zambia using samples from community-based, cross-sectional surveys from 2008 to 2012. Participants were tested with a PfHRP2-based RDT and a finger prick blood sample was spotted onto filter paper for PCR analysis and used to prepare blood smears for microscopy. Species-specific, real-time, quantitative PCR (q-PCR) was performed on samples that tested positive either by microscopy, RDT or nested PCR. Results Of 3,292 total participants enrolled, 12 (0.4%) tested positive by microscopy and 42 (1.3%) by RDT. Of 3,213 (98%) samples tested by nested PCR, 57 (1.8%) were positive, resulting in 87 participants positive by at least one of the three tests. Of these, 61 tested positive for P. falciparum by q-PCR with copy numbers ≤ 2 x 103 copies/μL, 5 were positive for both P. falciparum and Plasmodium malariae and 2 were positive for P. malariae alone. RDT detected 32 (53%) of P. falciparum positives, failing to detect three of the dual infections with P. malariae. Among 2,975 participants enrolled during a low transmission period between 2009 and 2012, sensitivity of the PfHRP2-based RDT compared to nested PCR was only 17%, with specificity of >99%. The pfhrp gene was detected in 80% of P. falciparum positives; however, comparison of copy number between RDT negative and RDT positive samples suggested that RDT negatives resulted from low parasitaemia and not pfhrp2 gene deletion. Conclusions Low-density P. falciparum infections not identified by currently used PfHRP2-based RDTs and the inability to detect non-falciparum malaria will hinder progress to further reduce malaria in low transmission settings of Zambia. More sensitive and specific diagnostic tests will likely be necessary to identify parasite reservoirs and achieve malaria elimination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0544-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Tamaki Kobayashi
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - David Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Sungano Mharakurwa
- Macha Research Trust, Choma, Zambia. .,W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - Clive J Shiff
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - William J Moss
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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Evaluation of the loop mediated isothermal DNA amplification (LAMP) kit for malaria diagnosis in P. vivax endemic settings of Colombia. PLoS Negl Trop Dis 2015; 9:e3453. [PMID: 25569550 PMCID: PMC4287555 DOI: 10.1371/journal.pntd.0003453] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 12/01/2014] [Indexed: 11/30/2022] Open
Abstract
Background Most commonly used malaria diagnostic tests, including microscopy and antigen-detecting rapid tests, cannot reliably detect low-density infections which are frequent in low transmission settings. Molecular methods such as polymerase chain reaction (PCR) are highly sensitive but remain too laborious for field deployment. In this study, the applicability of a malaria diagnosis kit based on loop-mediated isothermal amplification (mLAMP) was assessed in malaria endemic areas of Colombia with Plasmodium vivax predominance. Methodology/Principal Findings First, a passive case detection (PCD) study on 278 febrile patients recruited in Tierralta (department of Cordoba) was conducted to assess the diagnostic performance of the mLAMP method. Second, an active case detection (ACD) study on 980 volunteers was conducted in 10 sentinel sites with different epidemiological profiles. Whole blood samples were processed for microscopic and mLAMP diagnosis. Additionally RT-PCR and nested RT-PCR were used as reference tests. In the PCD study, P. falciparum accounted for 23.9% and P. vivax for 76.1% of the infections and no cases of mixed-infections were identified. Microscopy sensitivity for P. falciparum and P. vivax were 100% and 86.1%, respectively. mLAMP sensitivity for P. falciparum and P. vivax was 100% and 91.4%, respectively. In the ACD study, mLAMP detected 65 times more cases than microscopy. A high proportion (98.0%) of the infections detected by mLAMP was from volunteers without symptoms. Conclusions/Significance mLAMP sensitivity and specificity were comparable to RT-PCR. LAMP was significantly superior to microscopy and in P. vivax low-endemicity settings and under minimum infrastructure conditions, it displayed sensitivity and specificity similar to that of single-well RT-PCR for detection of both P. falciparum and P. vivax infections. Here, the dramatically increased detection of asymptomatic malaria infections by mLAMP demonstrates the usefulness of this new tool for diagnosis, surveillance, and screening in elimination strategies. The ability to detect and treat asymptomatic infections will be fundamental to eliminate malaria. This requires highly sensitive screening tests close enough to cases to enable rapid treatment. Very low parasitemias can be detected by molecular methods such as PCR; however, these techniques require considerable training and are restricted to reference laboratories. A new field-stable diagnostic kit for malaria based on loop-mediated isothermal DNA amplification (LAMP) is now commercially available. This LAMP kit is able to detect down to 1 parasite/µl of blood in less than 1 hour. In order to evaluate the feasibility of this LAMP kit as a tool for the detection of asymptomatic malaria in malaria endemic areas of Colombia with Plasmodium vivax predominance, we conducted field studies using the LAMP kit implemented in remote settings. We found that LAMP sensitivity and specificity were comparable to RT-PCR for detection of both P. falciparum and P. vivax infections and dramatically increased detection of asymptomatic malaria infections. This simple detection method for very low parasitemia raises opportunities and new strategies for malaria elimination.
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Kipanga PN, Omondi D, Mireji PO, Sawa P, Masiga DK, Villinger J. High-resolution melting analysis reveals low Plasmodium parasitaemia infections among microscopically negative febrile patients in western Kenya. Malar J 2014; 13:429. [PMID: 25399409 PMCID: PMC4246433 DOI: 10.1186/1475-2875-13-429] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 11/05/2014] [Indexed: 01/28/2023] Open
Abstract
Background Microscopy and rapid diagnostic tests (RDTs) are common tools for diagnosing malaria, but are deficient in detecting low Plasmodium parasitaemia. A novel molecular diagnostic tool (nPCR-HRM) that combines the sensitivity and specificity of nested PCR (nPCR) and direct PCR-high resolution melting analysis (dPCR-HRM) was developed. To evaluate patterns of anti-malarial drug administration when no parasites are detected, nPCR-HRM was employed to screen blood samples for low parasitaemia from febrile patients without microscopically detectable Plasmodium infections in a rural malaria-endemic setting. Methods Blood samples (n = 197) were collected in two islands of Lake Victoria, Kenya, from febrile patients without Plasmodium detectable by microscopy or RDTs. 18S rRNA gene sequences were amplified from extracted DNA by nPCR-HRM, nPCR, and dPCR-HRM to detect and differentiate Plasmodium parasites. The limits of detection (LoD) were compared using serial dilutions of the WHO International Standard for P. falciparum DNA. Data on administration of anti-malarials were collected to estimate prescription of anti-malarial drugs to patients with and without low parasitaemia Plasmodium infections. Results The coupled nPCR-HRM assay detected Plasmodium parasites with greater sensitivity (LoD = 236 parasites/mL) than either nPCR (LoD = 4,700 parasites/mL) or dPCR-HRM (LoD = 1,490 parasites/mL). Moreover, nPCR-HRM detected and differentiated low-parasitaemia infections in significantly greater proportions of patients than did either nPCR or dPCR-HRM (p-value <0.001). Among these low-parasitaemia infections, 67.7% of patients were treated with anti-malarials, whereas 81.5% of patients not infected with Plasmodium parasites were treated with anti-malarials. Conclusions The enhanced sensitivity of nPCR-HRM demonstrates limitations of differential febrile illness diagnostics in rural malaria endemic settings that confound epidemiological estimates of malaria, and lead to inadvertent misadministration of anti-malarial drugs. This is the first study that employs low-parasitaemia Plasmodium diagnostics to quantify the prescription of anti-malarial drugs to both non-malaria febrile patients and patients with low-parasitaemia Plasmodium infections. nPCR-HRM enhances low-parasitaemia malaria diagnosis and can potentially surmount the deficiencies of microscopy and RDT-based results in determining low-parasitaemia Plasmodium infection rates for evaluating malaria elimination efforts. The findings highlight the need for improved differential diagnostics of febrile illness in remote malaria endemic regions.
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Affiliation(s)
| | | | | | | | | | - Jandouwe Villinger
- Martin Lüscher Emerging Infectious Diseases (ML-EID) Laboratory, Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), P,O, Box 30772, Nairobi 00100, Kenya.
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Aydin-Schmidt B, Xu W, González IJ, Polley SD, Bell D, Shakely D, Msellem MI, Björkman A, Mårtensson A. Loop mediated isothermal amplification (LAMP) accurately detects malaria DNA from filter paper blood samples of low density parasitaemias. PLoS One 2014; 9:e103905. [PMID: 25105591 PMCID: PMC4126669 DOI: 10.1371/journal.pone.0103905] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/03/2014] [Indexed: 11/18/2022] Open
Abstract
Background Loop mediated isothermal amplification (LAMP) provides an opportunity for improved, field-friendly detection of malaria infections in endemic areas. However data on the diagnostic accuracy of LAMP for active case detection, particularly low-density parasitaemias, are lacking. We therefore evaluated the performance of a new LAMP kit compared with PCR using DNA from filter paper blood spots. Methods and Findings Samples from 865 fever patients and 465 asymptomatic individuals collected in Zanzibar were analysed for Pan (all species) and Pf (P. falciparum) DNA with the Loopamp MALARIA Pan/Pf kit. Samples were amplified at 65°C for 40 minutes in a real-time turbidimeter and results were compared with nested PCR. Samples with discordant results between LAMP and nested PCR were analysed with real-time PCR. The real-time PCR corrected nested PCR result was defined as gold standard. Among the 117 (13.5%) PCR detected P. falciparum infections from fever patients (mean parasite density 7491/µL, range 6–782,400) 115, 115 and 111 were positive by Pan-LAMP, Pf-LAMP and nested PCR, respectively. The sensitivities were 98.3% (95%CI 94–99.8) for both Pan and Pf-LAMP. Among the 54 (11.6%) PCR positive samples from asymptomatic individuals (mean parasite density 10/µL, range 0–4972) Pf-LAMP had a sensitivity of 92.7% (95%CI 80.1–98.5) for detection of the 41 P. falciparum infections. Pan-LAMP had sensitivities of 97% (95%CI 84.2–99.9) and 76.9% (95%CI 46.2–95) for detection of P. falciparum and P. malariae, respectively. The specificities for both Pan and Pf-LAMP were 100% (95%CI 99.1–100) in both study groups. Conclusion Both components of the Loopamp MALARIA Pan/Pf detection kit revealed high diagnostic accuracy for parasite detection among fever patients and importantly also among asymptomatic individuals of low parasite densities from minute blood volumes preserved on filter paper. These data support LAMPs potential role for improved detection of low-density malaria infections in pre-elimination settings.
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Affiliation(s)
- Berit Aydin-Schmidt
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
- Unit of infectious diseases, Karolinska University Hospital, Stockholm, Sweden
- * E-mail:
| | - Weiping Xu
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - Iveth J. González
- Department of Clinical Parasitology, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Spencer D. Polley
- Hospital for Tropical Diseases, University College London Hospitals, London, United Kingdom
- NIHR Biomedical Research Centre at University College London Hospitals NHS Foundation Trust and University College, London, United Kingdom
| | - David Bell
- Global Good Fund, Bellevue, Washington, United States of America
| | - Delér Shakely
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I. Msellem
- Zanzibar Malaria Elimination Program, Ministry of Health, Zanzibar, Tanzania
| | - Anders Björkman
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
- Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
- Center for Clinical Research, Sörmland County Council, Sörmland, Sweden
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Fridley GE, Le H, Yager P. Highly sensitive immunoassay based on controlled rehydration of patterned reagents in a 2-dimensional paper network. Anal Chem 2014; 86:6447-53. [PMID: 24882058 PMCID: PMC4082385 DOI: 10.1021/ac500872j] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 05/31/2014] [Indexed: 11/28/2022]
Abstract
We have demonstrated a multistep 2-dimensional paper network immunoassay based on controlled rehydration of patterned, dried reagents. Previous work has shown that signal enhancement improves the limit of detection in 2-dimensional paper network assays, but until now, reagents have only been included as wet or dried in separate conjugate pads placed at the upstream end of the assay device. Wet reagents are not ideal for point-of-care because they must be refrigerated and typically limit automation and require more user steps. Conjugate pads allow drying but do not offer any control of the reagent distribution upon rehydration and can be a source of error when pads do not contact the assay membrane uniformly. Furthermore, each reagent is dried on a separate pad, increasing the fabrication complexity when implementing multistep assays that require several different reagents. Conversely, our novel method allows for consistent, controlled rehydration from patterned reagent storage depots directly within the paper membrane. In this assay demonstration, four separate reagents were patterned in different regions of the assay device: a gold-antibody conjugate used for antigen detection and three different signal enhancement components that must not be mixed until immediately before use. To show the viability of patterning and drying reagents directly onto a paper device for dry reagent storage and subsequent controlled release, we tested this device with the malaria antigen Plasmodium falciparum histidine-rich protein 2 (PfHRP2) as an example of target analyte. In this demonstration, the signal enhancement step increases the visible signal by roughly 3-fold and decreases the analytical limit of detection by 2.75-fold.
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Affiliation(s)
- Gina E. Fridley
- University of Washington, Department of Bioengineering, Box 355061, Seattle, Washington 98195, United States
| | - Huy Le
- University of Washington, Department of Bioengineering, Box 355061, Seattle, Washington 98195, United States
| | - Paul Yager
- University of Washington, Department of Bioengineering, Box 355061, Seattle, Washington 98195, United States
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Johansson EW, Gething PW, Hildenwall H, Mappin B, Petzold M, Peterson SS, Selling KE. Diagnostic testing of pediatric fevers: meta-analysis of 13 national surveys assessing influences of malaria endemicity and source of care on test uptake for febrile children under five years. PLoS One 2014; 9:e95483. [PMID: 24748201 PMCID: PMC3991688 DOI: 10.1371/journal.pone.0095483] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 03/26/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In 2010, the World Health Organization revised guidelines to recommend diagnosis of all suspected malaria cases prior to treatment. There has been no systematic assessment of malaria test uptake for pediatric fevers at the population level as countries start implementing guidelines. We examined test use for pediatric fevers in relation to malaria endemicity and treatment-seeking behavior in multiple sub-Saharan African countries in initial years of implementation. METHODS AND FINDINGS We compiled data from national population-based surveys reporting fever prevalence, care-seeking and diagnostic use for children under five years in 13 sub-Saharan African countries in 2009-2011/12 (n = 105,791). Mixed-effects logistic regression models quantified the influence of source of care and malaria endemicity on test use after adjusting for socioeconomic covariates. Results were stratified by malaria endemicity categories: low (PfPR2-10<5%), moderate (PfPR2-10 5-40%), high (PfPR2-10>40%). Among febrile under-fives surveyed, 16.9% (95% CI: 11.8%-21.9%) were tested. Compared to hospitals, febrile children attending non-hospital sources (OR: 0.62, 95% CI: 0.56-0.69) and community health workers (OR: 0.31, 95% CI: 0.23-0.43) were less often tested. Febrile children in high-risk areas had reduced odds of testing compared to low-risk settings (OR: 0.51, 95% CI: 0.42-0.62). Febrile children in least poor households were more often tested than in poorest (OR: 1.63, 95% CI: 1.39-1.91), as were children with better-educated mothers compared to least educated (OR: 1.33, 95% CI: 1.16-1.54). CONCLUSIONS Diagnostic testing of pediatric fevers was low and inequitable at the outset of new guidelines. Greater testing is needed at lower or less formal sources where pediatric fevers are commonly managed, particularly to reach the poorest. Lower test uptake in high-risk settings merits further investigation given potential implications for diagnostic scale-up in these areas. Findings could inform continued implementation of new guidelines to improve access to and equity in point-of-care diagnostics use for pediatric fevers.
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Affiliation(s)
- Emily White Johansson
- International Maternal and Child Health, Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden
- * E-mail:
| | - Peter W. Gething
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Helena Hildenwall
- Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
| | - Bonnie Mappin
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Max Petzold
- Center for Applied Biostatistics, University of Gothenburg, Gothenburg, Sweden
| | - Stefan Swartling Peterson
- International Maternal and Child Health, Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden
- Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
- School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Katarina Ekholm Selling
- International Maternal and Child Health, Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden
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