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Vincent JP, Existe AV, Komaki-Yasuda K, Boncy J, Kano S. Performance of the procedure for ultra-rapid extraction and loop-mediated isothermal amplification (PURE-LAMP) method to detect malaria in Haiti. Infect Dis Poverty 2023; 12:53. [PMID: 37217984 DOI: 10.1186/s40249-023-01097-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/24/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Malaria continues to cause burden in various parts of the world. Haiti, a Caribbean country, is among those aiming to eliminate malaria within a few years. Two surveys were conducted in Haiti during which we aimed to evaluate the performance of the simple and rapid procedure for ultra-rapid extraction-loop-mediated isothermal amplification (PURE-LAMP) method with dried blood spots as an alternative diagnostic method for malaria in the context of low to very low rates of transmission. METHODS Febrile and afebrile people were recruited from three administrative divisions within Haiti: Nippes, Sud and Grand'Anse, during the summers of 2017 (early August to early September) and 2018 (late July to late August). Their blood samples were tested by microscopy, rapid diagnostic tests (RDT), PURE-LAMP and nested PCR to detect Plasmodium infection. Sensitivity, specificity, positive and negative predictive values and kappa statistics were estimated with the nested PCR results as the gold standard. RESULTS Among 1074 samples analyzed, a positive rate of 8.3% was calculated based on the nested PCR results. Among febrile participants, the rates in 2017 and 2018 were 14.6% and 1.4%, respectively. Three positives were detected among 172 afebrile participants in 2018 by PURE-LAMP and nested PCR, and all three were from the same locality. There was no afebrile participants recruited in 2017. The PURE-LAMP, RDT and microscopy had respective sensitivities of 100%, 85.4% and 49.4%. All of the testing methods had specificities over 99%. CONCLUSIONS This study confirmed the high performance of the PURE-LAMP method to detect Plasmodium infection with dried blood spots and recommends its use in targeted mass screening and treatment activities in low endemic areas of malaria.
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Affiliation(s)
- Jeanne Perpétue Vincent
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, 305-8575, Japan
- Unité d'Épidémiologie des Maladies Émergentes, Institut Pasteur, Paris, France
| | | | - Kanako Komaki-Yasuda
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan
| | - Jacques Boncy
- Laboratoire National de Santé Publique, 6120, Port-au-Prince, Haiti
| | - Shigeyuki Kano
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan.
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, 305-8575, Japan.
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Kassa MW, Hasang W, Barateiro A, Damelang T, Brewster J, Dombrowski JG, Longley RJ, Chung AW, Wunderlich G, Mueller I, Aitken EH, Marinho CRF, Rogerson SJ. Acquisition of antibodies to Plasmodium falciparum and Plasmodium vivax antigens in pregnant women living in a low malaria transmission area of Brazil. Malar J 2022; 21:360. [PMID: 36457056 PMCID: PMC9714246 DOI: 10.1186/s12936-022-04402-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Pregnant women have increased susceptibility to Plasmodium falciparum malaria and acquire protective antibodies over successive pregnancies. Most studies that investigated malaria antibody responses in pregnant women are from high transmission areas in sub-Saharan Africa, while reports from Latin America are scarce and inconsistent. The present study sought to explore the development of antibodies against P. falciparum and Plasmodium vivax antigens in pregnant women living in a low transmission area in the Brazilian Amazon. METHODS In a prospective cohort study, plasma samples from 408 pregnant women (of whom 111 were infected with P. falciparum, 96 had infections with P. falciparum and P. vivax, and 201 had no Plasmodium infection) were used to measure antibody levels. Levels of IgG and opsonizing antibody to pregnancy-specific variant surface antigens (VSAs) on infected erythrocytes (IEs), 10 recombinant VAR2CSA Duffy binding like (DBL domains), 10 non-pregnancy-specific P. falciparum merozoite antigens, and 10 P. vivax antigens were measured by flow cytometry, ELISA, and multiplex assays. Antibody levels and seropositivity among the groups were compared. RESULTS Antibodies to VSAs on P. falciparum IEs were generally low but were higher in currently infected women and women with multiple P. falciparum episodes over pregnancy. Many women (21%-69%) had antibodies against each individual VAR2CSA DBL domain, and antibodies to DBLs correlated with each other (r ≥ 0.55, p < 0.0001), but not with antibody to VSA or history of infection. Infection with either malaria species was associated with higher seropositivity rate for antibodies against P. vivax proteins, adjusted odds ratios (95% CI) ranged from 5.6 (3.2, 9.7), p < 0.0001 for PVDBPII-Sal1 to 15.7 (8.3, 29.7), p < 0.0001 for PvTRAg_2. CONCLUSIONS Pregnant Brazilian women had low levels of antibodies to pregnancy-specific VSAs that increased with exposure. They frequently recognized both VAR2CSA DBL domains and P. vivax antigens, but only the latter varied with infection. Apparent antibody prevalence is highly dependent on the assay platform used.
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Affiliation(s)
- Meseret W. Kassa
- grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Level 5, 792 Elizabeth St, University of Melbourne, Melbourne, VIC 3000 Australia
| | - Wina Hasang
- grid.1008.90000 0001 2179 088XDepartment of Infectious Diseases, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC Australia
| | - André Barateiro
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Timon Damelang
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, University of Melbourne, Melbourne, VIC Australia
| | - Jessica Brewster
- grid.1042.70000 0004 0432 4889Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC Australia
| | - Jamille G. Dombrowski
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rhea J. Longley
- grid.1042.70000 0004 0432 4889Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medical Biology, University of Melbourne, Melbourne, VIC Australia
| | - Amy W. Chung
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, University of Melbourne, Melbourne, VIC Australia
| | - Gerhard Wunderlich
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ivo Mueller
- grid.1042.70000 0004 0432 4889Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medical Biology, University of Melbourne, Melbourne, VIC Australia
| | - Elizabeth H. Aitken
- grid.1008.90000 0001 2179 088XDepartment of Infectious Diseases, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, University of Melbourne, Melbourne, VIC Australia
| | - Claudio R. F. Marinho
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Stephen J. Rogerson
- grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Level 5, 792 Elizabeth St, University of Melbourne, Melbourne, VIC 3000 Australia ,grid.1008.90000 0001 2179 088XDepartment of Infectious Diseases, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC Australia
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Elmardi KA, Adam I, Malik EM, Kafy HT, Abdin MS, Kleinschmidt I, Kremers S. Impact of malaria control interventions on malaria infection and anaemia in areas with irrigated schemes: a cross-sectional population-based study in Sudan. BMC Infect Dis 2021; 21:1248. [PMID: 34906083 PMCID: PMC8670187 DOI: 10.1186/s12879-021-06929-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/01/2021] [Indexed: 11/29/2022] Open
Abstract
Background While the overall burden of malaria is still high, the global technical strategy for malaria advocates for two sets of interventions: vector control-based prevention and diagnosis and prompt effective treatment of malaria cases. This study aimed to assess the performance of malaria interventions on malaria infection and anaemia in irrigated areas in Sudan. Methods Based on the Sudan 2016 national malaria indicator survey, data for two states (Gezira and Sennar), characterized by large-irrigated schemes, were analysed. Four community-level malaria interventions were used as contextual variables: utilization of malaria diagnosis, utilization of Artemisinin-based combination therapy (ACT), utilization of long-lasting insecticidal nets (LLINs) and coverage with indoor residual spraying (IRS). Association between these interventions and two outcomes: malaria infection and anaemia, was assessed separately. Malaria infection was assessed in all age groups while anaemia was assessed in children under 5 years. Multilevel multiple logistic regression analysis were conducted. Results Among 4478 individuals involved in this study distributed over 47 clusters, the overall malaria infection rate was 3.0% and 56.5% of the children under 5 years (total = 322) were anaemic. Except for IRS coverage (69.6%), the average utilization of interventions was relatively low: 52.3% for utilization of diagnosis, 33.0% for utilization of ACTs and 18.6% for LLINs utilization. The multi-level multiple logistic regression model showed that only IRS coverage was associated with malaria infection (Odds ratio 0.83 per 10% coverage, 95%Confidence Interval (95%CI) 0.74–0.94, p = 0.003) indicating that a higher level of IRS coverage was associated with less malaria infection. Anaemia was not associated with any intervention (all p values larger than 0.1). Conclusions Malaria transmission in Gezira and Sennar areas is low. IRS, with insecticide to which vectors are susceptible, is an effective malaria control intervention in irrigated schemes. Community utilization of other interventions was not associated with malaria infection in this study. This may be due to the low utilization of these interventions. However, individual use of LLINs provide personal protection. This study failed to establish an association between anaemia and malaria control interventions in low transmission areas. The higher level of malaria infection in urban areas is a cause for concern.
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Affiliation(s)
- Khalid Abdelmutalab Elmardi
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan. .,Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands.
| | - Ishag Adam
- Department of Obstetrics and Gynecology, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | | | - Hmooda Toto Kafy
- Directorate General of Primary Health Care, Federal Ministry of Health, Khartoum, Sudan
| | - Mogahid Sheikheldien Abdin
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan
| | - Immo Kleinschmidt
- MRC International Statistics and Epidemiology Group, Departments of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Stef Kremers
- Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
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Ashton RA, Prosnitz D, Andrada A, Herrera S, Yé Y. Evaluating malaria programmes in moderate- and low-transmission settings: practical ways to generate robust evidence. Malar J 2020; 19:75. [PMID: 32070357 PMCID: PMC7027277 DOI: 10.1186/s12936-020-03158-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/09/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Many countries have made substantial progress in scaling-up and sustaining malaria intervention coverage, leading to more focalized and heterogeneous transmission in many settings. Evaluation provides valuable information for programmes to understand if interventions have been implemented as planned and with quality, if the programme had the intended impact on malaria burden, and to guide programmatic decision-making. Low-, moderate-, and heterogeneous-transmission settings present unique evaluation challenges because of dynamic and targeted intervention strategies. This paper provides illustration of evaluation approaches and methodologies for these transmission settings, and suggests how to answer evaluation questions specific to the local context. METHODS The Roll Back Malaria Monitoring and Evaluation Reference Group formed a task force in October 2017 to lead development of this framework. The task force includes representatives from National Malaria Programmes, funding agencies, and malaria research and implementing partners. The framework builds on existing guidance for process and outcome evaluations and impact evaluations specifically in high transmission settings. RESULTS The theory of change describes how evaluation questions asked by national malaria programmes in different contexts influence evaluation design. The transmission setting, existing stratification, and data quality and availability are also key considerations. The framework is intended for adaption by countries to their local context, and use for evaluation at sub-national level. Confirmed malaria incidence is recommended as the primary impact indicator due to its sensitivity to detect changes in low-transmission settings. It is expected that process evaluations provide sufficient evidence for programme monitoring and improvement, while impact evaluations are needed following adoption of new mixes of interventions, operational strategies, tools or policies, particularly in contexts of changing malaria epidemiology. Impact evaluations in low-, moderate-, or heterogeneous-transmission settings will likely use plausibility designs, and methods highlighted by the framework include interrupted time series, district-level dose-response analyses, and constructed control methods. Triangulating multiple data sources and analyses is important to strengthen the plausibility argument. CONCLUSIONS This framework provides a structure to assist national malaria programmes and partners to design evaluations in low-, moderate- or heterogeneous-transmission settings. Emphasizing a continuous cycle along the causal pathway linking process evaluation to impact evaluation and then programmatic decision-making, the framework provides practical guidance in evaluation design, analysis, and interpretation to ensure that the evaluation meets national malaria programme priority questions and guides decision-making at national and sub-national levels.
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Affiliation(s)
- Ruth A Ashton
- MEASURE Evaluation, Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 2300, New Orleans, LA, USA.
| | | | | | - Samantha Herrera
- MEASURE Evaluation, ICF, Rockville, MD, USA.,Save the Children, Washington, DC, USA
| | - Yazoumé Yé
- MEASURE Evaluation, ICF, Rockville, MD, USA
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5
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Zainabadi K, Nyunt MM, Plowe CV. An improved nucleic acid extraction method from dried blood spots for amplification of Plasmodium falciparum kelch13 for detection of artemisinin resistance. Malar J 2019; 18:192. [PMID: 31185976 PMCID: PMC6558694 DOI: 10.1186/s12936-019-2817-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/18/2019] [Indexed: 12/15/2022] Open
Abstract
Background Mutational analysis of the Plasmodium falciparum kelch 13 (k13) gene is routinely performed to track the emergence and spread of artemisinin resistance. Surveillance of resistance markers has been impeded by the difficulty of extracting sufficient DNA from low parasite density infections common in low-transmission settings, such as Southeast Asia. This problem can be overcome by collecting large volumes of venous blood. Efficient methods for extracting and amplifying k13 from dried blood spots (DBS) would facilitate resistance surveillance. Methods Methods for k13 amplification from standard Whatman 3MM DBS (stored for 14 days at 28 °C with 80% relative humidity) were optimized by systematically testing different extraction conditions. Conditions that improved parasite DNA recovery as assessed by quantitative polymerase chain reaction (PCR) of 18S rDNA were then tested for their impact on k13 PCR amplification. Results The optimized protocol for amplification of k13 from DBS is markedly more sensitive than standard methods using commercial kits. Using this method, k13 was successfully amplified from laboratory-created DBS samples with parasite densities as low as 500 parasites/mL. Importantly, the method recovers both DNA and RNA, making it compatible with RNA-based ultrasensitive techniques currently in use. Conclusions The optimized DBS protocol should facilitate drug resistance surveillance, especially in low-transmission settings where clinical malaria infections with high parasite densities are rare. Electronic supplementary material The online version of this article (10.1186/s12936-019-2817-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kayvan Zainabadi
- Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA. .,Center for Global Health, Weill Cornell Medicine, New York, NY, USA.
| | - Myaing M Nyunt
- Duke Global Health Institute, Duke University, Durham, NC, USA
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6
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Jiram AI, Ooi CH, Rubio JM, Hisam S, Karnan G, Sukor NM, Artic MM, Ismail NP, Alias NW. Evidence of asymptomatic submicroscopic malaria in low transmission areas in Belaga district, Kapit division, Sarawak, Malaysia. Malar J 2019; 18:156. [PMID: 31046769 PMCID: PMC6498596 DOI: 10.1186/s12936-019-2786-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/22/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Malaysia has declared its aim to eliminate malaria with a goal of achieving zero local transmission by the year 2020. However, targeting the human reservoir of infection, including those with asymptomatic infection is required to achieve malaria elimination. Diagnosing asymptomatic malaria is not as straightforward due to the obvious lack of clinical manifestations and often subpatent level of parasites. Accurate diagnosis of malaria is important for providing realistic estimates of malaria burden and preventing misinformed interventions. Low levels of parasitaemia acts as silent reservoir of transmission thus remains infectious to susceptible mosquito vectors. Hence, the aim of this study is to investigate the prevalence of asymptomatic submicroscopic malaria (SMM) in the District of Belaga, Sarawak. METHODS In 2013, a total of 1744 dried blood spots (DBS) were obtained from residents of 8 longhouses who appeared healthy. Subsequently, 251 venous blood samples were collected from residents of 2 localities in 2014 based on the highest number of submicroscopic cases from prior findings. Thin and thick blood films were prepared from blood obtained from all participants in this study. Microscopic examination were carried out on all samples and a nested and nested multiplex PCR were performed on samples collected in 2013 and 2014 respectively. RESULTS No malaria parasites were detected in all the Giemsa-stained blood films. However, of the 1744 samples, 29 (1.7%) were positive for Plasmodium vivax by PCR. Additionally, of the 251 samples, the most prevalent mono-infection detected by PCR was Plasmodium falciparum 50 (20%), followed by P. vivax 39 (16%), P. knowlesi 9 (4%), and mixed infections 20 (8%). CONCLUSIONS This research findings conclude evidence of Plasmodium by PCR, among samples previously undetectable by routine blood film microscopic examination, in local ethnic minority who are clinically healthy. SMM in Belaga district is attributed not only to P. vivax, but also to P. falciparum and P. knowlesi. In complementing efforts of programme managers, there is a need to increase surveillance for SMM nationwide to estimate the degree of SMM that warrant measures to block new transmission of malaria.
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Affiliation(s)
- Adela Ida Jiram
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia.
| | - Choo Huck Ooi
- Vector Borne Diseases Section, Sarawak Health Department, Ministry of Health Malaysia, Diplomatik Road, Off Bako Road, Petra Jaya, 93050, Kuching, Sarawak, Malaysia
| | - José Miguel Rubio
- Malaria & Emerging Parasitic Diseases Laboratory, Parasitology Department, National Centre of Microbiology, Instituto de Salud Carlos III (ISCIII), Carretera de Majadahonda - Pozuelo, km. 2,200, Majadahonda, 28220, Madrid, Spain
| | - Shamilah Hisam
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Govindarajoo Karnan
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Nurnadiah Mohd Sukor
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Mohd Mafie Artic
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Nor Parina Ismail
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Nor Wahida Alias
- Parasitology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
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Abstract
Mass drug administration (MDA) of antimalarials has re-emerged as a recommended tool for interrupting malaria transmission, but evidence from low endemicity settings is scarce. A trial in Zanzibar found that two rounds of MDA made no significant impact on malaria incidence, and many questions on the optimal mode and setting for implementing MDA remain unanswered. A more thorough understanding of local sources and drivers of transmission, and a better toolbox for evaluating interventions in near-elimination settings are essential.Please see related research article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1202-8 .
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Affiliation(s)
- Manuel W Hetzel
- Swiss Tropical and Public Health Institute, P.O. Box, 4002, Basel, Switzerland. .,University of Basel, Petersplatz 1, 4003, Basel, Switzerland.
| | - Blaise Genton
- Swiss Tropical and Public Health Institute, P.O. Box, 4002, Basel, Switzerland.,University of Basel, Petersplatz 1, 4003, Basel, Switzerland.,Division of Infectious Diseases and Department of Community Health, University Hospital (CHUV), Rue du Bugnon 44, 1011, Lausanne, Switzerland
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8
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Morris U, Msellem MI, Mkali H, Islam A, Aydin-Schmidt B, Jovel I, Shija SJ, Khamis M, Ali SM, Hodzic L, Magnusson E, Poirot E, Bennett A, Sachs MC, Tarning J, Mårtensson A, Ali AS, Björkman A. A cluster randomised controlled trial of two rounds of mass drug administration in Zanzibar, a malaria pre-elimination setting-high coverage and safety, but no significant impact on transmission. BMC Med 2018; 16:215. [PMID: 30526588 PMCID: PMC6287359 DOI: 10.1186/s12916-018-1202-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/29/2018] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Mass drug administration (MDA) has the potential to interrupt malaria transmission and has been suggested as a tool for malaria elimination in low-endemic settings. This study aimed to determine the effectiveness and safety of two rounds of MDA in Zanzibar, a pre-elimination setting. METHODS A cluster randomised controlled trial was conducted in 16 areas considered as malaria hotspots, with an annual parasite index of > 0.8%. The areas were randomised to eight intervention and eight control clusters. The intervention included two rounds of MDA with dihydroartemisinin-piperaquine and single low-dose primaquine 4 weeks apart in May-June 2016. Primary and secondary outcomes were cumulative confirmed malaria case incidences 6 months post-MDA and parasite prevalences determined by PCR 3 months post-MDA. Additional outcomes included intervention coverage, treatment adherence, occurrence of adverse events, and cumulative incidences 3, 12, and 16 months post-MDA. RESULTS Intervention coverage was 91.0% (9959/10944) and 87.7% (9355/10666) in the first and second rounds, respectively; self-reported adherence was 82.0% (881/1136) and 93.7% (985/1196). Adverse events were reported in 11.6% (147/1268) and 3.2% (37/1143) of post-MDA survey respondents after both rounds respectively. No serious adverse event was reported. No difference in cumulative malaria case incidence was observed between the control and intervention arms 6 months post-MDA (4.2 and 3.9 per 1000 population; p = 0.94). Neither was there a difference in PCR-determined parasite prevalences 3 months post-MDA (1.4% and 1.7%; OR = 1.0, p = 0.94), although having received at least the first MDA was associated with reduced odds of malaria infection (aOR = 0.35; p = 0.02). Among confirmed malaria cases at health facilities, 26.0% and 26.3% reported recent travel outside Zanzibar in the intervention and control shehias (aOR ≥ 85; p ≤ 0.001). CONCLUSIONS MDA was implemented with high coverage, adherence, and tolerability. Despite this, no significant impact on transmission was observed. The findings suggest that two rounds of MDA in a single year may not be sufficient for a sustained impact on transmission in a pre-elimination setting, especially when the MDA impact is restricted by imported malaria. Importantly, this study adds to the limited evidence for the use of MDA in low transmission settings in sub-Saharan Africa. TRIAL REGISTRATION ClinicalTrials.gov, NCT02721186 (registration date: March 29, 2016).
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Affiliation(s)
- Ulrika Morris
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I. Msellem
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Humphrey Mkali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Atiqul Islam
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Irina Jovel
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Shija Joseph Shija
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Mwinyi Khamis
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Safia Mohammed Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Lamija Hodzic
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Ellinor Magnusson
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Eugenie Poirot
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, USA
| | - Michael C. Sachs
- Biostatistics Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Bangkok, Thailand
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, UK
| | - Andreas Mårtensson
- Department of Women’s and Children’s Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
| | - Abdullah S. Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Anders Björkman
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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Kattenberg JH, Erhart A, Truong MH, Rovira-Vallbona E, Vu KAD, Nguyen THN, Nguyen VH, Nguyen VV, Bannister-Tyrrell M, Theisen M, Bennet A, Lover AA, Tran TD, Nguyen XX, Rosanas-Urgell A. Characterization of Plasmodium falciparum and Plasmodium vivax recent exposure in an area of significantly decreased transmission intensity in Central Vietnam. Malar J 2018; 17:180. [PMID: 29703200 PMCID: PMC5923009 DOI: 10.1186/s12936-018-2326-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/18/2018] [Indexed: 11/30/2022] Open
Abstract
Background In Vietnam, malaria transmission has been reduced to very low levels over the past 20 years, and as a consequence, the country aims to eliminate malaria by 2030. This study aimed to characterize the dynamics and extent of the parasite reservoir in Central Vietnam, in order to further target elimination strategies and surveillance. Methods A 1-year prospective cohort study (n = 429) was performed in three rural communities in Quang Nam province. Six malaria screenings were conducted between November 2014 and November 2015, including systematic clinical examination and blood sampling for malaria parasite identification, as well as molecular and serological analysis of the study population. Malaria infections were detected by light microscopy (LM) and quantitative real time PCR (qPCR), while exposure to Plasmodium falciparum and Plasmodium vivax was measured in the first and last survey by ELISA for PfAMA1, PfGLURP R2, PvAMA1, and PvMSP1-19. Classification and regression trees were used to define seropositivity and recent exposure. Results Four malaria infections (2 P. falciparum, 2 P. vivax) were detected in the same village by qPCR and/or LM. No fever cases were attributable to malaria. At the same time, the commune health centre (serving a larger area) reported few cases of confirmed malaria cases. Nevertheless, serological data proved that 13.5% of the surveyed population was exposed to P. falciparum and/or P. vivax parasites during the study period, of which 32.6% were seronegative at the start of the study, indicating ongoing transmission in the area. Risk factor analysis for seroprevalence and exposure to P. falciparum and/or P. vivax identified structural or economic risk factors and activity/behaviour-related factors, as well as spatial heterogeneity at the village level. Conclusions Previous studies in Central Vietnam demonstrated high occurrence of asymptomatic and sub-microscopic infections. However, in this study very few asymptomatic infections were detected despite serological evidence of continued transmission. Nonetheless, the factors associated with spatial heterogeneity in transmission could be evaluated using serological classification of recent exposure, which supports the usefulness of serological methods to monitor malaria transmission. Electronic supplementary material The online version of this article (10.1186/s12936-018-2326-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Annette Erhart
- Institute of Tropical Medicine, Nationalestraat 155, 2000, Antwerp, Belgium.,MRC Unit, Fajara, The Gambia.,Global Health Institute, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Minh Hieu Truong
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | | | - Khac Anh Dung Vu
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Thi Hong Ngoc Nguyen
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Van Hong Nguyen
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Van Van Nguyen
- Provincial Malaria Station Quang Nam/Center for Malaria and Goitre Control, Quang Nam Province, Tam Ky, Vietnam
| | | | | | - Adam Bennet
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Andrew A Lover
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Thanh Duong Tran
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Xuan Xa Nguyen
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Anna Rosanas-Urgell
- Institute of Tropical Medicine, Nationalestraat 155, 2000, Antwerp, Belgium.
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10
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Zainabadi K, Adams M, Han ZY, Lwin HW, Han KT, Ouattara A, Thura S, Plowe CV, Nyunt MM. A novel method for extracting nucleic acids from dried blood spots for ultrasensitive detection of low-density Plasmodium falciparum and Plasmodium vivax infections. Malar J 2017; 16:377. [PMID: 28923054 PMCID: PMC5604154 DOI: 10.1186/s12936-017-2025-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 09/07/2017] [Indexed: 11/10/2022] Open
Abstract
Background Greater Mekong Subregion countries are committed to eliminating Plasmodium falciparum malaria by 2025. Current elimination interventions target infections at parasite densities that can be detected by standard microscopy or rapid diagnostic tests (RDTs). More sensitive detection methods have been developed to detect lower density “asymptomatic” infections that may represent an important transmission reservoir. These ultrasensitive polymerase chain reaction (usPCR) tests have been used to identify target populations for mass drug administration (MDA). To date, malaria usPCR tests have used either venous or capillary blood sampling, which entails complex sample collection, processing and shipping requirements. An ultrasensitive method performed on standard dried blood spots (DBS) would greatly facilitate the molecular surveillance studies needed for targeting elimination interventions. Methods A highly sensitive method for detecting Plasmodium falciparum and P. vivax 18S ribosomal RNA from DBS was developed by empirically optimizing nucleic acid extraction conditions. The limit of detection (LoD) was determined using spiked DBS samples that were dried and stored under simulated field conditions. Further, to assess its utility for routine molecular surveillance, two cross-sectional surveys were performed in Myanmar during the wet and dry seasons. Results The lower LoD of the DBS-based ultrasensitive assay was 20 parasites/mL for DBS collected on Whatman 3MM filter paper and 23 parasites/mL for Whatman 903 Protein Saver cards—equivalent to 1 parasite per 50 µL DBS. This is about 5000-fold more sensitive than standard RDTs and similar to the LoD of ≤16–22 parasites/mL reported for other ultrasensitive methods based on whole blood. In two cross-sectional surveys in Myanmar, nearly identical prevalence estimates were obtained from contemporaneous DBS samples and capillary blood samples collected during the wet and dry season. Conclusions The DBS-based ultrasensitive method described in this study shows equal sensitivity as previously described methods based on whole blood, both in its limit of detection and prevalence estimates in two field surveys. The reduced cost and complexity of this method will allow for the scale-up of surveillance studies to target MDA and other malaria elimination interventions, and help lead to a better understanding of the epidemiology of low-density malaria infections. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2025-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kayvan Zainabadi
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, USA
| | - Matthew Adams
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, USA
| | - Zay Yar Han
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Hnin Wai Lwin
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Kay Thwe Han
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Amed Ouattara
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, USA
| | - Si Thura
- Community Partners International, Yangon, Myanmar
| | - Christopher V Plowe
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, USA
| | - Myaing M Nyunt
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, USA.
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11
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Baum E, Sattabongkot J, Sirichaisinthop J, Kiattibutr K, Jain A, Taghavian O, Lee MC, Huw Davies D, Cui L, Felgner PL, Yan G. Common asymptomatic and submicroscopic malaria infections in Western Thailand revealed in longitudinal molecular and serological studies: a challenge to malaria elimination. Malar J 2016; 15:333. [PMID: 27333893 PMCID: PMC4918199 DOI: 10.1186/s12936-016-1393-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/15/2016] [Indexed: 11/27/2022] Open
Abstract
Background Despite largely successful control efforts, malaria remains a significant public health problem in Thailand. Based on microscopy, the northwestern province of Tak, once Thailand’s highest burden area, is now considered a low-transmission region. However, microscopy is insensitive to detect low-level parasitaemia, causing gross underestimation of parasite prevalence in areas where most infections are subpatent. The objective of this study was to assess the current epidemiology of malaria prevalence using molecular and serological detection methods, and to profile the antibody responses against Plasmodium as it relates to age, seasonal changes and clinical manifestations during infection. Three comprehensive cross-sectional surveys were performed in a sentinel village and from febrile hospital patients, and whole blood samples were collected from infants to elderly adults. Genomic DNA isolated from cellular fraction was screened by quantitative-PCR for the presence of Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale and Plasmodium knowlesi. Plasma samples were probed on protein microarray to obtain antibody response profiles from the same individuals. Results Within the studied community, 90.2 % of Plasmodium infections were submicroscopic and asymptomatic, including a large number of mixed-species infections. Amongst febrile patients, mixed-species infections comprised 68 % of positive cases, all of which went misdiagnosed and undertreated. All samples tested showed serological reactivity to Plasmodium antigens. There were significant differences in the rates of antibody acquisition against P. falciparum and P. vivax, and age-related differences in species-specific immunodominance of response. Antibodies against Plasmodium increased along the ten-month study period. Febrile patients had stronger antibody responses than asymptomatic carriers. Conclusions Despite a great decline in malaria prevalence, transmission is still ongoing at levels undetectable by traditional methods. As current surveillance methods focus on case management, malaria transmission in Thailand will not be interrupted if asymptomatic submicroscopic infections are not detected and treated. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1393-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elisabeth Baum
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA.
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Kirakorn Kiattibutr
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Aarti Jain
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Omid Taghavian
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Ming-Chieh Lee
- Program in Public Health, University of California Irvine, Irvine, CA, USA
| | - D Huw Davies
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA, USA
| | - Philip L Felgner
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Guiyun Yan
- Program in Public Health, University of California Irvine, Irvine, CA, USA
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12
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Morris U, Xu W, Msellem MI, Schwartz A, Abass A, Shakely D, Cook J, Bhattarai A, Petzold M, Greenhouse B, Ali AS, Björkman A, Fröberg G, Mårtensson A. Characterising temporal trends in asymptomatic Plasmodium infections and transporter polymorphisms during transition from high to low transmission in Zanzibar, 2005-2013. Infect Genet Evol 2015; 33:110-7. [PMID: 25917493 PMCID: PMC10445533 DOI: 10.1016/j.meegid.2015.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/14/2015] [Accepted: 04/18/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Improved understanding of the asymptomatic malaria parasite reservoir is a prerequisite to pursue malaria elimination efforts. We therefore characterised temporal trends and transporter polymorphisms in asymptomatic Plasmodium infections during the transition from high to low transmission in Zanzibar. METHODS Healthy individuals participating in cross-sectional surveys conducted 2005-2013 were screened for asymptomatic malaria by PCR. Complexity/diversity of infection and transporter polymorphisms were assessed in Plasmodium falciparum positive samples. Symptomatic samples were included for comparison of polymorphisms in 2013. RESULTS PCR-determined parasite prevalence declined from 21.1% (CI95% 17.4-24.9) to 2.3% (CI95% 1.7-2.9) from 2005 to 2013. P. falciparum remained the predominant species; prevalence was highest in children and young adults aged 5-25 years. Parasite densities and complexity of infection, but not population genetic diversity of P. falciparum, decreased from 2005-2009. pfcrt 76T (99.2-64.7%, p < 0.001) and pfmdr1 86Y frequencies (89.4-66.7%, p = 0.03) decreased over time. Pfmdr1 (a.a.86,184,1246) YYY and YYD haplotypes were more frequent in asymptomatic than symptomatic infections in 2013 (p < 0.001). CONCLUSIONS There is a declining, albeit persistent, reservoir of parasites present at low-densities in asymptomatic individuals in Zanzibar. This study revealed important characteristics of the remaining parasite population, including intriguing temporal trends in molecular markers associated with antimalarial resistance, which need to be further investigated.
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Affiliation(s)
- Ulrika Morris
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
| | - Weiping Xu
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I Msellem
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania
| | - Alanna Schwartz
- Department of Medicine, University of California San Francisco, CA, USA
| | - Ali Abass
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania
| | - Delér Shakely
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden; Department of Medicine, Kungälv Hospital, Kungälv, Sweden
| | - Jackie Cook
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden; Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania
| | - Achuyt Bhattarai
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Max Petzold
- Health Metrics at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, CA, USA
| | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania
| | - Anders Björkman
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Gabrielle Fröberg
- Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden; Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden; Centre for Clinical Research Sörmland, Uppsala University, Sweden
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