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Khan O, Ajadi JO, Hossain MP. Predicting malaria outbreak in The Gambia using machine learning techniques. PLoS One 2024; 19:e0299386. [PMID: 38753678 PMCID: PMC11098333 DOI: 10.1371/journal.pone.0299386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/09/2024] [Indexed: 05/18/2024] Open
Abstract
Malaria is the most common cause of death among the parasitic diseases. Malaria continues to pose a growing threat to the public health and economic growth of nations in the tropical and subtropical parts of the world. This study aims to address this challenge by developing a predictive model for malaria outbreaks in each district of The Gambia, leveraging historical meteorological data. To achieve this objective, we employ and compare the performance of eight machine learning algorithms, including C5.0 decision trees, artificial neural networks, k-nearest neighbors, support vector machines with linear and radial kernels, logistic regression, extreme gradient boosting, and random forests. The models are evaluated using 10-fold cross-validation during the training phase, repeated five times to ensure robust validation. Our findings reveal that extreme gradient boosting and decision trees exhibit the highest prediction accuracy on the testing set, achieving 93.3% accuracy, followed closely by random forests with 91.5% accuracy. In contrast, the support vector machine with a linear kernel performs less favorably, showing a prediction accuracy of 84.8% and underperforming in specificity analysis. Notably, the integration of both climatic and non-climatic features proves to be a crucial factor in accurately predicting malaria outbreaks in The Gambia.
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Affiliation(s)
- Ousman Khan
- Department of Mathematics, College of Computing and Mathematics, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - Jimoh Olawale Ajadi
- Department of Mathematics, College of Computing and Mathematics, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
- Interdisciplinary Research Center for Refining & Advanced Chemicals, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - M. Pear Hossain
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
- Laboratory of Data Discovery for Health Limited (D24H), Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China
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2
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Xu E, Goel V, Baguma E, Ayebare E, Hollingsworth BD, Brown-Marusiak A, Giandomenico D, Reyes R, Ntaro M, Mulogo EM, Boyce RM. Evolution of Spatial Risk of Malaria Infection After a Pragmatic Chemoprevention Program in Response to Severe Flooding in Rural Western Uganda. J Infect Dis 2024; 229:173-182. [PMID: 37584317 PMCID: PMC10786254 DOI: 10.1093/infdis/jiad348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 04/21/2023] [Accepted: 08/14/2023] [Indexed: 08/17/2023] Open
Abstract
BACKGROUND Malaria epidemics result from extreme precipitation and flooding, which are increasing with global climate change. Local adaptation and mitigation strategies will be essential to prevent excess morbidity and mortality. METHODS We investigated the spatial risk of malaria infection at multiple timepoints after severe flooding in rural western Uganda employing longitudinal household surveys measuring parasite prevalence and leveraging remotely sensed information to inform spatial models of malaria risk in the 3 months after flooding. RESULTS We identified clusters of malaria risk emerging in areas (1) that showed the greatest changes in Normalized Difference Vegetation Index from pre- to postflood and (2) where residents were displaced for longer periods of time and had lower access to long-lasting insecticidal nets, both of which were associated with a positive malaria rapid diagnostic test result. The disproportionate risk persisted despite a concurrent chemoprevention program that achieved high coverage. CONCLUSIONS The findings enhance our understanding not only of the spatial evolution of malaria risk after flooding, but also in the context of an effective intervention. The results provide a "proof of concept" for programs aiming to prevent malaria outbreaks after flooding using a combination of interventions. Further study of mitigation strategies-and particularly studies of implementation-is urgently needed.
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Affiliation(s)
- Erin Xu
- School of Medicine, UNC School of Medicine
| | - Varun Goel
- Department of Geography
- Carolina Population Center, University of North Carolina at Chapel Hill
| | - Emmanuel Baguma
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Uganda
| | - Emmanuel Ayebare
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Uganda
| | | | | | | | | | - Moses Ntaro
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Uganda
| | - Edgar M Mulogo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Uganda
| | - Ross M Boyce
- Carolina Population Center, University of North Carolina at Chapel Hill
- Department of Epidemiology, Gillings School of Global Public Health
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill
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3
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Hutchins H, Bradley J, Pretorius E, Teixeira da Silva E, Vasileva H, Jones RT, Ndiath MO, Dit Massire Soumare H, Mabey D, Nante EJ, Martins C, Logan JG, Slater H, Drakeley C, D'Alessandro U, Rodrigues A, Last AR. Protocol for a cluster randomised placebo-controlled trial of adjunctive ivermectin mass drug administration for malaria control on the Bijagós Archipelago of Guinea-Bissau: the MATAMAL trial. BMJ Open 2023; 13:e072347. [PMID: 37419638 PMCID: PMC10335573 DOI: 10.1136/bmjopen-2023-072347] [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: 01/30/2023] [Accepted: 06/20/2023] [Indexed: 07/09/2023] Open
Abstract
INTRODUCTION As malaria declines, innovative tools are required to further reduce transmission and achieve elimination. Mass drug administration (MDA) of artemisinin-based combination therapy (ACT) is capable of reducing malaria transmission where coverage of control interventions is already high, though the impact is short-lived. Combining ACT with ivermectin, an oral endectocide shown to reduce vector survival, may increase its impact, while also treating ivermectin-sensitive co-endemic diseases and minimising the potential impact of ACT resistance in this context. METHODS AND ANALYSIS MATAMAL is a cluster-randomised placebo-controlled trial. The trial is being conducted in 24 clusters on the Bijagós Archipelago, Guinea-Bissau, where the peak prevalence of Plasmodium falciparum (Pf) parasitaemia is approximately 15%. Clusters have been randomly allocated to receive MDA with dihydroartemisinin-piperaquine and either ivermectin or placebo. The primary objective is to determine whether the addition of ivermectin MDA is more effective than dihydroartemisinin-piperaquine MDA alone in reducing the prevalence of P. falciparum parasitaemia, measured during peak transmission season after 2 years of seasonal MDA. Secondary objectives include assessing prevalence after 1 year of MDA; malaria incidence monitored through active and passive surveillance; age-adjusted prevalence of serological markers indicating exposure to P. falciparum and anopheline mosquitoes; vector parous rates, species composition, population density and sporozoite rates; prevalence of vector pyrethroid resistance; prevalence of artemisinin resistance in P. falciparum using genomic markers; ivermectin's impact on co-endemic diseases; coverage estimates; and the safety of combined MDA. ETHICS AND DISSEMINATION The trial has been approved by the London School of Hygiene and Tropical Medicine's Ethics Committee (UK) (19156) and the Comite Nacional de Eticas de Saude (Guinea-Bissau) (084/CNES/INASA/2020). Results will be disseminated in peer-reviewed publications and in discussion with the Bissau-Guinean Ministry of Public Health and participating communities. TRIAL REGISTRATION NUMBER NCT04844905.
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Affiliation(s)
- Harry Hutchins
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - John Bradley
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Elizabeth Pretorius
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Eunice Teixeira da Silva
- Projecto de Saúde Bandim, Bissau, Guinea-Bissau
- Ministério de Saúde Pública, Bissau, Guinea-Bissau
| | - Hristina Vasileva
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Robert T Jones
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - David Mabey
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Ernesto Jose Nante
- Programa Nacional de Luta Contra o Paludismo, Ministério de Saúde, Bissau, Guinea-Bissau
| | | | - James G Logan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
- Arctech Innovation, London, UK
| | | | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Amabelia Rodrigues
- Projecto de Saúde Bandim, Bissau, Guinea-Bissau
- Ministério de Saúde Pública, Bissau, Guinea-Bissau
| | - Anna R Last
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
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Aidoo EK, Aboagye FT, Botchway FA, Osei-Adjei G, Appiah M, Duku-Takyi R, Sakyi SA, Amoah L, Badu K, Asmah RH, Lawson BW, Krogfelt KA. Reactive Case Detection Strategy for Malaria Control and Elimination: A 12 Year Systematic Review and Meta-Analysis from 25 Malaria-Endemic Countries. Trop Med Infect Dis 2023; 8:180. [PMID: 36977181 PMCID: PMC10058581 DOI: 10.3390/tropicalmed8030180] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/23/2023] [Accepted: 03/09/2023] [Indexed: 03/30/2023] Open
Abstract
Reactive case detection (RACD) is the screening of household members and neighbors of index cases reported in passive surveillance. This strategy seeks asymptomatic infections and provides treatment to break transmission without testing or treating the entire population. This review discusses and highlights RACD as a recommended strategy for the detection and elimination of asymptomatic malaria as it pertains in different countries. Relevant studies published between January 2010 and September 2022 were identified mainly through PubMed and Google Scholar. Search terms included "malaria and reactive case detection", "contact tracing", "focal screening", "case investigation", "focal screen and treat". MedCalc Software was used for data analysis, and the findings from the pooled studies were analyzed using a fixed-effect model. Summary outcomes were then presented using forest plots and tables. Fifty-four (54) studies were systematically reviewed. Of these studies, 7 met the eligibility criteria based on risk of malaria infection in individuals living with an index case < 5 years old, 13 met the eligibility criteria based on risk of malaria infection in an index case household member compared with a neighbor of an index case, and 29 met the eligibility criteria based on risk of malaria infection in individuals living with index cases, and were included in the meta-analysis. Individuals living in index case households with an average risk of 2.576 (2.540-2.612) were more at risk of malaria infection and showed pooled results of high variation heterogeneity chi-square = 235.600, (p < 0.0001) I2 = 98.88 [97.87-99.89]. The pooled results showed that neighbors of index cases were 0.352 [0.301-0.412] times more likely to have a malaria infection relative to index case household members, and this result was statistically significant (p < 0.001). The identification and treatment of infectious reservoirs is critical to successful malaria elimination. Evidence to support the clustering of infections in neighborhoods, which necessitates the inclusion of neighboring households as part of the RACD strategy, was presented in this review.
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Affiliation(s)
- Ebenezer Krampah Aidoo
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana; (F.A.B.); (G.O.-A.); (M.A.); (R.D.-T.)
| | - Frank Twum Aboagye
- Biomedical and Public Health Research Unit, Council for Scientific and Industrial Research-Water Research Institute, Accra AH 38, Ghana;
| | - Felix Abekah Botchway
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana; (F.A.B.); (G.O.-A.); (M.A.); (R.D.-T.)
| | - George Osei-Adjei
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana; (F.A.B.); (G.O.-A.); (M.A.); (R.D.-T.)
| | - Michael Appiah
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana; (F.A.B.); (G.O.-A.); (M.A.); (R.D.-T.)
| | - Ruth Duku-Takyi
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana; (F.A.B.); (G.O.-A.); (M.A.); (R.D.-T.)
| | - Samuel Asamoah Sakyi
- Department of Molecular Medicine, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi AK 039, Ghana;
| | - Linda Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra LG 581, Ghana;
| | - Kingsley Badu
- Department of Theoretical & Applied Biology, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi AK 039, Ghana; (K.B.); (B.W.L.)
| | - Richard Harry Asmah
- Department of Biomedical Sciences, School of Basic and Biomedical Science, University of Health & Allied Sciences, Ho PMB 31, Ghana;
| | - Bernard Walter Lawson
- Department of Theoretical & Applied Biology, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi AK 039, Ghana; (K.B.); (B.W.L.)
| | - Karen Angeliki Krogfelt
- Department of Science and Environment, Unit of Molecular and Medical Biology, The PandemiX Center, Roskilde University, 4000 Roskilde, Denmark
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, 2300 Copenhagen, Denmark
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Deng C, Wu W, Yuan Y, Li G, Zhang H, Zheng S, Li M, Tan R, Wang Y, Nadia J, Feng D, Li D, Wu Z, Xu Q, Li C, Wang Z, Liang Y, Doehl JSP, Su X, Bacar A, Said Abdallah K, Mohamed H, Msa Mliva A, Wellems TE, Song J. Malaria Control by Mass Drug Administration With Artemisinin Plus Piperaquine on Grande Comore Island, Union of Comoros. Open Forum Infect Dis 2023; 10:ofad076. [PMID: 36910690 PMCID: PMC10003749 DOI: 10.1093/ofid/ofad076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Background Mass drug administration (MDA) is a powerful tool for malaria control, but the medicines to use, dosing, number of rounds, and potential selection of drug resistance remain open questions. Methods Two monthly rounds of artemisinin-piperaquine (AP), each comprising 2 daily doses, were administered across the 7 districts of Grande Comore Island. In 3 districts, low-dose primaquine (PMQLD) was also given on the first day of each monthly round. Plasmodium falciparum malaria rates, mortality, parasitemias, adverse events, and genetic markers of potential drug resistance were evaluated. Results Average population coverages of 80%-82% were achieved with AP in 4 districts (registered population 258 986) and AP + PMQLD in 3 districts (83 696). The effectiveness of MDA was 96.27% (95% confidence interval [CI], 95.27%-97.06%; P < .00001) in the 4 AP districts and 97.46% (95% CI, 94.54%-98.82%; P < .00001) in the 3 AP + PMQLD districts. In comparative statistical modeling, the effectiveness of the 2 monthly rounds on Grande Comore Island was nearly as high as that of 3 monthly rounds of AP or AP + PMQLD in our earlier study on Anjouan Island. Surveys of pre-MDA and post-MDA samples showed no significant changes in PfK13 polymorphism rates, and no PfCRT mutations previously linked to piperaquine resistance in Southeast Asia were identified. Conclusions MDA with 2 monthly rounds of 2 daily doses of AP was highly effective on Grande Comore Island. The feasibility and lower expense of this 2-month versus 3-month regimen of AP may offer advantages for MDA programs in appropriate settings.
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Affiliation(s)
- Changsheng Deng
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Wanting Wu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Yueming Yuan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Guoming Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Hongying Zhang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Shaoqin Zheng
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Mingqiang Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Ruixiang Tan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Yuxin Wang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Julie Nadia
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Danhong Feng
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Di Li
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Zhibing Wu
- First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Qin Xu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.,First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Changqing Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.,First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Zhenhua Wang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Yuan Liang
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Johannes S P Doehl
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Xinzhuan Su
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Affane Bacar
- National Malaria Center of The Union of Comoros, Moroni, The Union of Comoros
| | - Kamal Said Abdallah
- National Malaria Center of The Union of Comoros, Moroni, The Union of Comoros
| | - Hafidhou Mohamed
- National Malaria Center of The Union of Comoros, Moroni, The Union of Comoros
| | - Ahamada Msa Mliva
- National Malaria Center of The Union of Comoros, Moroni, The Union of Comoros
| | - Thomas E Wellems
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Jianping Song
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.,First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
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Stadler E, Cromer D, Ogunlade S, Ongoiba A, Doumbo S, Kayentao K, Traore B, Crompton PD, Portugal S, Davenport MP, Khoury DS. Evidence for exposure dependent carriage of malaria parasites across the dry season: modelling analysis of longitudinal data. Malar J 2023; 22:42. [PMID: 36737743 PMCID: PMC9898990 DOI: 10.1186/s12936-023-04461-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND In malaria endemic regions, transmission of Plasmodium falciparum parasites is often seasonal with very low transmission during the dry season and high transmission in the wet season. Parasites survive the dry season within some individuals who experience prolonged carriage of parasites and are thought to 'seed' infection in the next transmission season. METHODS Dry season carriers and their role in the subsequent transmission season are characterized using a combination of mathematical simulations and data analysis of previously described data from a longitudinal study in Mali of individuals aged 3 months-12 years (n = 579). RESULTS Simulating the life-history of individuals experiencing repeated exposure to infection predicts that dry season carriage is more likely in the oldest, most exposed and most immune individuals. This hypothesis is supported by the data from Mali, which shows that carriers are significantly older, experience a higher biting rate at the beginning of the transmission season and develop clinical malaria later than non-carriers. Further, since the most exposed individuals in a community are most likely to be dry season carriers, this is predicted to enable a more than twofold faster spread of parasites into the mosquito population at the start of the subsequent wet season. CONCLUSIONS Carriage of malaria parasites over the months-long dry season in Mali is most likely in the older, more exposed and more immune children. These children may act as super-spreaders facilitating the fast spread of parasites at the beginning of the next transmission season.
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Affiliation(s)
- Eva Stadler
- grid.1005.40000 0004 4902 0432The Kirby Institute, UNSW Sydney, Sydney, NSW 2052 Australia
| | - Deborah Cromer
- grid.1005.40000 0004 4902 0432The Kirby Institute, UNSW Sydney, Sydney, NSW 2052 Australia
| | - Samson Ogunlade
- grid.1005.40000 0004 4902 0432The Kirby Institute, UNSW Sydney, Sydney, NSW 2052 Australia
| | - Aissata Ongoiba
- grid.461088.30000 0004 0567 336XMalaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique, and Technology of Bamako, 91094 Bamako, Mali
| | - Safiatou Doumbo
- grid.461088.30000 0004 0567 336XMalaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique, and Technology of Bamako, 91094 Bamako, Mali
| | - Kassoum Kayentao
- grid.461088.30000 0004 0567 336XMalaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique, and Technology of Bamako, 91094 Bamako, Mali
| | - Boubacar Traore
- grid.461088.30000 0004 0567 336XMalaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique, and Technology of Bamako, 91094 Bamako, Mali
| | - Peter D. Crompton
- grid.419681.30000 0001 2164 9667Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, USA
| | - Silvia Portugal
- grid.419681.30000 0001 2164 9667Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, USA
| | - Miles P. Davenport
- grid.1005.40000 0004 4902 0432The Kirby Institute, UNSW Sydney, Sydney, NSW 2052 Australia
| | - David S. Khoury
- grid.1005.40000 0004 4902 0432The Kirby Institute, UNSW Sydney, Sydney, NSW 2052 Australia
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Nankabirwa JI, Arinaitwe E, Briggs J, Rek J, Rosenthal PJ, Kamya MR, Olwoch P, Smith DL, Rodriguez-Barraquer I, Dorsey G, Greenhouse B. Simulating the Impacts of Augmenting Intensive Vector Control with Mass Drug Administration or Test-and-Treat Strategies on the Malaria Infectious Reservoir. Am J Trop Med Hyg 2022; 107:1028-1035. [PMID: 36191870 PMCID: PMC9709029 DOI: 10.4269/ajtmh.21-0953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 06/29/2022] [Indexed: 12/24/2022] Open
Abstract
Highly effective vector control can reduce malaria burden significantly, but individuals with parasitemia provide a potential reservoir for onward transmission. We performed an empirical, non-parametric simulation based on cohort data from Tororo District, Uganda-an area with historically high but recently reduced malaria transmission-to estimate the effects of mass drug administration (MDA) and test-and-treat on parasite prevalence. We estimate that a single round of MDA would have accelerated declines in parasite prevalence dramatically over 2 years (cumulative parasite prevalence ratio [PPR], 0.34). This decline was mostly during the first year of administration (PPR, 0.23) and waned by 23 months (PPR, 0.74). Test-and-treat using a highly sensitive diagnostic had nearly the same effect as MDA at 1 year (PPR, 0.27) and required many fewer treatments. The impact of test-and-treat using a standard diagnostic was modest (PPR, 0.58 at 1 year). Our analysis suggests that in areas experiencing a dramatic reduction in malaria prevalence, MDA or test-and-treat with a highly sensitive diagnostic may be an effective way of reducing or eliminating the infectious reservoir temporarily. However, for sustained benefits, repeated rounds of the intervention or additional interventions are required.
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Affiliation(s)
- Joaniter I. Nankabirwa
- Department of Internal Medicine, Makerere University College of Health Sciences, Kampala, Uganda
- Infectious Disease Research Collaboration, Kampala, Uganda
| | | | - Jessica Briggs
- Department of Infectious Diseases, School of Medicine, University of California, San Francisco, California
| | - John Rek
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Philip J. Rosenthal
- Department of Infectious Diseases, School of Medicine, University of California, San Francisco, California
| | - Moses R. Kamya
- Department of Internal Medicine, Makerere University College of Health Sciences, Kampala, Uganda
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Peter Olwoch
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - David L. Smith
- Department of Health Metrics Sciences, University of Washington, Seattle, Washington
| | - Isabel Rodriguez-Barraquer
- Department of Infectious Diseases, School of Medicine, University of California, San Francisco, California
| | - Grant Dorsey
- Department of Infectious Diseases, School of Medicine, University of California, San Francisco, California
| | - Bryan Greenhouse
- Department of Infectious Diseases, School of Medicine, University of California, San Francisco, California
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Malloy GSP, Brandeau ML. When Is Mass Prophylaxis Cost-Effective for Epidemic Control? A Comparison of Decision Approaches. Med Decis Making 2022; 42:1052-1063. [PMID: 35591754 DOI: 10.1177/0272989x221098409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND For certain communicable disease outbreaks, mass prophylaxis of uninfected individuals can curtail new infections. When an outbreak emerges, decision makers could benefit from methods to quickly determine whether mass prophylaxis is cost-effective. We consider 2 approaches: a simple decision model and machine learning meta-models. The motivating example is plague in Madagascar. METHODS We use a susceptible-exposed-infectious-removed (SEIR) epidemic model to derive a decision rule based on the fraction of the population infected, effective reproduction ratio, infection fatality rate, quality-adjusted life-year loss associated with death, prophylaxis effectiveness and cost, time horizon, and willingness-to-pay threshold. We also develop machine learning meta-models of a detailed model of plague in Madagascar using logistic regression, random forest, and neural network models. In numerical experiments, we compare results using the decision rule and the meta-models to results obtained using the simulation model. We vary the initial fraction of the population infected, the effective reproduction ratio, the intervention start date and duration, and the cost of prophylaxis. LIMITATIONS We assume homogeneous mixing and no negative side effects due to antibiotic prophylaxis. RESULTS The simple decision rule matched the SEIR model outcome in 85.4% of scenarios. Using data for a 2017 plague outbreak in Madagascar, the decision rule correctly indicated that mass prophylaxis was not cost-effective. The meta-models were significantly more accurate, with an accuracy of 92.8% for logistic regression, 95.8% for the neural network model, and 96.9% for the random forest model. CONCLUSIONS A simple decision rule using minimal information about an outbreak can accurately evaluate the cost-effectiveness of mass prophylaxis for outbreak mitigation. Meta-models of a complex disease simulation can achieve higher accuracy but with greater computational and data requirements and less interpretability. HIGHLIGHTS We use a susceptible-exposed-infectious-removed model and net monetary benefit to derive a simple decision rule to evaluate the cost-effectiveness of mass prophylaxis.We use the example of plague in Madagascar to compare the performance of the analytically derived decision rule to that of machine learning meta-models trained on a stochastic dynamic transmission model.We assess the accuracy of each approach for different combinations of disease dynamics and intervention scenarios.The machine learning meta-models are more accurate predictors of mass prophylaxis cost-effectiveness. However, the simple decision rule is also accurate and may be a preferred substitute in low-resource settings.
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Affiliation(s)
- Giovanni S P Malloy
- Department of Management Science and Engineering, Stanford University, Stanford, CA, USA
| | - Margaret L Brandeau
- Department of Management Science and Engineering, Stanford University, Stanford, CA, USA
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9
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Abstract
BACKGROUND Studies evaluating mass drug administration (MDA) in malarious areas have shown reductions in malaria immediately following the intervention. However, these effects vary by endemicity and are not sustained. Since the 2013 version of this Cochrane Review on this topic, additional studies have been published. OBJECTIVES Primary objectives To assess the sustained effect of MDA with antimalarial drugs on: - the reduction in malaria transmission in moderate- to high-transmission settings; - the interruption of transmission in very low- to low-transmission settings. Secondary objective To summarize the risk of drug-associated adverse effects following MDA. SEARCH METHODS We searched several trial registries, citation databases, conference proceedings, and reference lists for relevant articles up to 11 February 2021. We also communicated with researchers to identify additional published and unpublished studies. SELECTION CRITERIA Randomized controlled trials (RCTs) and non-randomized studies comparing MDA to no MDA with balanced co-interventions across study arms and at least two geographically distinct sites per study arm. DATA COLLECTION AND ANALYSIS Two review authors independently assessed trials for eligibility and extracted data. We calculated relative risk (RR) and rate ratios with corresponding 95% confidence intervals (CIs) to compare prevalence and incidence, respectively, in MDA compared to no-MDA groups. We stratified analyses by malaria transmission and by malaria species. For cluster-randomized controlled trials (cRCTs), we adjusted standard errors using the intracluster correlation coefficient. We assessed the certainty of the evidence using the GRADE approach. For non-randomized controlled before-and-after (CBA) studies, we summarized the data using difference-in-differences (DiD) analyses. MAIN RESULTS Thirteen studies met our criteria for inclusion. Ten were cRCTs and three were CBAs. Cluster-randomized controlled trials Moderate- to high-endemicity areas (prevalence ≥ 10%) We included data from two studies conducted in The Gambia and Zambia. At one to three months after MDA, the Plasmodium falciparum (hereafter, P falciparum) parasitaemia prevalence estimates may be higher compared to control but the CIs included no effect (RR 1.76, 95% CI 0.58 to 5.36; Zambia study; low-certainty evidence); parasitaemia incidence was probably lower (RR 0.61, 95% CI 0.40 to 0.92; The Gambia study; moderate-certainty evidence); and confirmed malaria illness incidence may be substantially lower, but the CIs included no effect (rate ratio 0.41, 95% CI 0.04 to 4.42; Zambia study; low-certainty evidence). At four to six months after MDA, MDA showed little or no effect on P falciparum parasitaemia prevalence (RR 1.18, 95% CI 0.89 to 1.56; The Gambia study; moderate-certainty evidence) and, no persisting effect was demonstrated with parasitaemia incidence (rate ratio 0.91, 95% CI 0.55 to 1.50; The Gambia study). Very low- to low-endemicity areas (prevalence < 10%) Seven studies from Cambodia, Laos, Myanmar (two studies), Vietnam, Zambia, and Zanzibar evaluated the effects of multiple rounds of MDA on P falciparum. Immediately following MDA (less than one month after MDA), parasitaemia prevalence was reduced (RR 0.12, 95% CI 0.03 to 0.52; one study; low-certainty evidence). At one to three months after MDA, there was a reduction in both parasitaemia incidence (rate ratio 0.37, 95% CI 0.21 to 0.55; 1 study; moderate-certainty evidence) and prevalence (RR 0.25, 95% CI 0.15 to 0.41; 7 studies; low-certainty evidence). For confirmed malaria incidence, absolute rates were low, and it is uncertain whether MDA had an effect on this outcome (rate ratio 0.58, 95% CI 0.12 to 2.73; 2 studies; very low-certainty evidence). For P falciparum prevalence, the relative differences declined over time, from RR 0.63 (95% CI 0.36 to 1.12; 4 studies) at four to six months after MDA, to RR 0.86 (95% CI 0.55 to 1.36; 5 studies) at 7 to 12 months after MDA. Longer-term prevalence estimates showed overall low absolute risks, and relative effect estimates of the effect of MDA on prevalence varied from RR 0.82 (95% CI 0.20 to 3.34) at 13 to 18 months after MDA, to RR 1.25 (95% CI 0.25 to 6.31) at 31 to 36 months after MDA in one study. Five studies from Cambodia, Laos, Myanmar (2 studies), and Vietnam evaluated the effect of MDA on Plasmodium vivax (hereafter, P vivax). One month following MDA, P vivax prevalence was lower (RR 0.18, 95% CI 0.08 to 0.40; 1 study; low-certainty evidence). At one to three months after MDA, there was a reduction in P vivax prevalence (RR 0.15, 95% CI 0.10 to 0.24; 5 studies; low-certainty evidence). The immediate reduction on P vivax prevalence was not sustained over time, from RR 0.78 (95% CI 0.63 to 0.95; 4 studies) at four to six months after MDA, to RR 1.12 (95% CI 0.94 to 1.32; 5 studies) at 7 to 12 months after MDA. One of the studies in Myanmar provided estimates of longer-term effects, where overall absolute risks were low, ranging from RR 0.81 (95% CI 0.44 to 1.48) at 13 to 18 months after MDA, to RR 1.20 (95% CI 0.44 to 3.29) at 31 to 36 months after MDA. Non-randomized studies Three CBA studies were conducted in moderate- to high-transmission areas in Burkina Faso, Kenya, and Nigeria. There was a reduction in P falciparum parasitaemia prevalence in MDA groups compared to control groups during MDA (DiD range: -15.8 to -61.4 percentage points), but the effect varied at one to three months after MDA (DiD range: 14.9 to -41.1 percentage points). AUTHORS' CONCLUSIONS: In moderate- to high-transmission settings, no studies reported important effects on P falciparum parasitaemia prevalence within six months after MDA. In very low- to low-transmission settings, parasitaemia prevalence and incidence were reduced initially for up to three months for both P falciparum and P vivax; longer-term data did not demonstrate an effect after four months, but absolute risks in both intervention and control groups were low. No studies provided evidence of interruption of malaria transmission.
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Affiliation(s)
- Monica P Shah
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jimee Hwang
- U.S. President's Malaria Initiative, Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
- Global Health Group, University of California San Francisco, San Francisco, USA
| | - Leslie Choi
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Kim A Lindblade
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - S Patrick Kachur
- Department of Population and Family Health, Columbia University Medical Center, New York, NY, USA
| | - Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
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10
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Boyce RM, Hollingsworth BD, Baguma E, Xu E, Goel V, Brown-Marusiak A, Muhindo R, Reyes R, Ntaro M, Siedner MJ, Staedke SG, Juliano JJ, Mulogo EM. Dihydroartemisinin-piperaquine chemoprevention and malaria incidence after severe flooding: evaluation of a pragmatic intervention in rural Uganda. Clin Infect Dis 2021; 74:2191-2199. [PMID: 34499116 DOI: 10.1093/cid/ciab781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Malaria epidemics are a well-described phenomenon after extreme precipitation and flooding, which account for nearly half of global disasters over the past two decades. Yet few studies have examined mitigation measures to prevent post-flood malaria epidemics. METHODS We conducted an evaluation of a malaria chemoprevention program implemented in response to severe flooding in western Uganda. Children ≤12 years of age from one village were eligible to receive 3 monthly rounds of dihydroartemisinin-piperaquine (DP). Two neighboring villages served as controls. Malaria cases were defined as individuals with a positive rapid diagnostic test result as recorded in health center registers. We performed a difference-in-differences analysis to estimate changes in the incidence and test positivity of malaria between intervention and control villages. RESULTS A total of 554 children received at least one round of chemoprevention with 75% participating in at least two rounds. Compared to control villages, we estimated a 53.4% reduction (aRR 0.47, 95% CI 0.34 - 0.62, p<.01) in malaria incidence and a 30% decrease in the test positivity rate (aRR=0.70, CI 0.50 - 0.97, p=0.03) in the intervention village in the six months post-intervention. The impact was greatest among children receiving the intervention, but decreased incidence was also observed in older children and adults (aRR=0.57, CI 0.38-0.84, p<.01). CONCLUSIONS Three rounds of chemoprevention with DP delivered under pragmatic conditions reduced the incidence of malaria after severe flooding in western Uganda. These findings provide a proof-of-concept for the use of malaria chemoprevention to reduce excess disease burden associated with severe flooding.
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Affiliation(s)
- Ross M Boyce
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Brandon D Hollingsworth
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Emma Baguma
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Erin Xu
- School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Varun Goel
- Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Amanda Brown-Marusiak
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rabbison Muhindo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Raquel Reyes
- Division of Hospital Medicine, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Moses Ntaro
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Mark J Siedner
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA, USA
| | - Sarah G Staedke
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | - Jonathan J Juliano
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Edgar M Mulogo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
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11
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Siddiqui FA, Liang X, Cui L. Plasmodium falciparum resistance to ACTs: Emergence, mechanisms, and outlook. Int J Parasitol Drugs Drug Resist 2021; 16:102-118. [PMID: 34090067 PMCID: PMC8188179 DOI: 10.1016/j.ijpddr.2021.05.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/06/2021] [Accepted: 05/21/2021] [Indexed: 01/18/2023]
Abstract
Emergence and spread of resistance in Plasmodium falciparum to the frontline treatment artemisinin-based combination therapies (ACTs) in the epicenter of multidrug resistance of Southeast Asia threaten global malaria control and elimination. Artemisinin (ART) resistance (or tolerance) is defined clinically as delayed parasite clearance after treatment with an ART drug. The resistance phenotype is restricted to the early ring stage and can be measured in vitro using a ring-stage survival assay. ART resistance is associated with mutations in the propeller domain of the Kelch family protein K13. As a pro-drug, ART is activated primarily by heme, which is mainly derived from hemoglobin digestion in the food vacuole. Activated ARTs can react promiscuously with a wide range of cellular targets, disrupting cellular protein homeostasis. Consistent with this mode of action for ARTs, the molecular mechanisms of K13-mediated ART resistance involve reduced hemoglobin uptake/digestion and increased cellular stress response. Mutations in other genes such as AP-2μ (adaptor protein-2 μ subunit), UBP-1 (ubiquitin-binding protein-1), and Falcipain 2a that interfere with hemoglobin uptake and digestion also increase resistance to ARTs. ART resistance has facilitated the development of resistance to the partner drugs, resulting in rapidly declining ACT efficacies. The molecular markers for resistance to the partner drugs are mostly associated with point mutations in the two food vacuole membrane transporters PfCRT and PfMDR1, and amplification of pfmdr1 and the two aspartic protease genes plasmepsin 2 and 3. It has been observed that mutations in these genes can have opposing effects on sensitivities to different partner drugs, which serve as the principle for designing triple ACTs and drug rotation. Although clinical ACT resistance is restricted to Southeast Asia, surveillance for drug resistance using in vivo clinical efficacy, in vitro assays, and molecular approaches is required to prevent or slow down the spread of resistant parasites.
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Affiliation(s)
- Faiza Amber Siddiqui
- Department of Internal Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Xiaoying Liang
- Department of Internal Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Liwang Cui
- Department of Internal Medicine, University of South Florida, Tampa, FL, 33612, USA.
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12
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Oyibo W, Ntadom G, Uhomoibhi P, Oresanya O, Ogbulafor N, Ajumobi O, Okoh F, Maxwell K, Ezeiru S, Nwokolo E, Amajoh C, Ezeigwe N, Audu M, Conway D. Geographical and temporal variation in reduction of malaria infection among children under 5 years of age throughout Nigeria. BMJ Glob Health 2021; 6:bmjgh-2020-004250. [PMID: 33632771 PMCID: PMC7908906 DOI: 10.1136/bmjgh-2020-004250] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/09/2021] [Accepted: 01/29/2021] [Indexed: 01/06/2023] Open
Abstract
INTRODUCTION Global progress in reducing malaria has stalled since 2015. Analysis of the situation is particularly needed in Nigeria, the country with by far the largest share of the burden, where approximately a quarter of all cases in the world are estimated to occur. METHODS We analysed data from three nationwide surveys (Malaria Indicator Surveys in 2010 and 2015 and a National Demographic and Health Survey in 2018), with malaria parasite prevalence in children under 5 years of age determined by sampling from all 36 states of Nigeria, and blood slide microscopy performed in the same accredited laboratory for all samples. Changes over time were evaluated by calculating prevalence ratio (PR) values with 95% CIs for each state, together with Mantel-Haenszel-adjusted PRs (PRadj) for each of the six major geopolitical zones of the country. RESULTS Between 2010 and 2018, there were significant reductions in parasite prevalence in 25 states, but not in the remaining 11 states. Prevalence decreased most in southern zones of the country (South West PRadj=0.53; South East PRadj=0.59; South South PRadj=0.51) and the North Central zone (PRadj=0.36). Changes in the north were less marked, but were significant and indicated overall reductions by more than 20% (North-West PRadj=0.74; North East PRadj=0.70). Changes in the south occurred mostly between 2010 and 2015, whereas those in the north were more gradual and most continued after 2015. Recent changes were not correlated with survey-reported variation in use of preventive measures. CONCLUSION Reductions in malaria infection in children under 5 have occurred in most individual states in Nigeria since 2010, but substantial geographical variation in the timing and extent indicate challenges to be overcome to enable global malaria reduction.
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Affiliation(s)
- Wellington Oyibo
- ANDI Centre of Excellence for Malaria Diagnosis, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Godwin Ntadom
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Perpetua Uhomoibhi
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | | | - Nnenna Ogbulafor
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Olufemi Ajumobi
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Festus Okoh
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | | | - Sonachi Ezeiru
- Catholic Relief Services (CRS), Federal Capital Territory, Abuja, Nigeria
| | | | | | - Nnenna Ezeigwe
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - Mohammed Audu
- National Malaria Elimination Programme (NMEP), Federal Ministry of Health, Abuja, Nigeria
| | - David Conway
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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13
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Jaiteh F, Okebe J, Masunaga Y, D'Alessandro U, Achan J, Gryseels C, de Vries D, Ribera JM, Grietens KP. Understanding adherence to reactive treatment of asymptomatic malaria infections in The Gambia. Sci Rep 2021; 11:1746. [PMID: 33462329 PMCID: PMC7813830 DOI: 10.1038/s41598-021-81468-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/18/2020] [Indexed: 11/29/2022] Open
Abstract
The impact of different types of reactive case detection and/or treatment strategies for malaria elimination depends on high coverage and participants’ adherence. However, strategies to optimise adherence are limited, particularly for people with asymptomatic or no infections. As part of a cluster-randomized trial to evaluate the effect of reactive treatment in The Gambia, all residents in the compound of a diagnosed clinical malaria patient received dihydro-artemisinin–piperaquine (DP). Using a mixed method approach, we assessed which factors contribute to adherence among the contacts of malaria cases that showed no symptoms. Adherence was defined as the proportion of compound members that (1) returned all medicine bags empty and (2) self-reported (3-day) treatment completion. Among the 273 individuals from 14 compounds who received DP, 227 (83.1%) were available for and willing to participate in the survey; 85.3% (233/273) returned empty medicine bags and 91.6% (208/227) self-reported treatment completion. Although clinical malaria was not considered a major health problem, reported adherence was high. The drivers of adherence were the strong sense of responsibility towards protecting the individual, compound and the village. Adherence can be optimised through a transdisciplinary implementation research process of engaging communities to bridge the gap between research goals and social realities.
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Affiliation(s)
- Fatou Jaiteh
- Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia. .,Medical Anthropology Unit, Institute of Tropical Medicine, Antwerp, Belgium. .,Amsterdam Institute of Social Science Research, Amsterdam, The Netherlands.
| | - Joseph Okebe
- Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia.,Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Yoriko Masunaga
- Medical Anthropology Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Amsterdam Institute of Social Science Research, Amsterdam, The Netherlands
| | - Umberto D'Alessandro
- Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Jane Achan
- Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Charlotte Gryseels
- Medical Anthropology Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Daniel de Vries
- Amsterdam Institute of Social Science Research, Amsterdam, The Netherlands
| | | | - Koen Peeters Grietens
- Medical Anthropology Unit, Institute of Tropical Medicine, Antwerp, Belgium.,PASS Suisse, Neuchâtel, Switzerland.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
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14
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Dabira ED, Soumare HM, Lindsay SW, Conteh B, Ceesay F, Bradley J, Kositz C, Broekhuizen H, Kandeh B, Fehr AE, Nieto-Sanchez C, Ribera JM, Peeters Grietens K, Smit MR, Drakeley C, Bousema T, Achan J, D'Alessandro U. Mass Drug Administration With High-Dose Ivermectin and Dihydroartemisinin-Piperaquine for Malaria Elimination in an Area of Low Transmission With High Coverage of Malaria Control Interventions: Protocol for the MASSIV Cluster Randomized Clinical Trial. JMIR Res Protoc 2020; 9:e20904. [PMID: 33211022 PMCID: PMC7714640 DOI: 10.2196/20904] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/28/2020] [Accepted: 08/03/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND With a decline in malaria burden, innovative interventions and tools are required to reduce malaria transmission further. Mass drug administration (MDA) of artemisinin-based combination therapy (ACT) has been identified as a potential tool to further reduce malaria transmission, where coverage of vector control interventions is already high. However, the impact is limited in time. Combining an ACT with an endectocide treatment that is able to reduce vector survival, such as ivermectin (IVM), could increase the impact of MDA and offer a new tool to reduce malaria transmission. OBJECTIVE The study objective is to evaluate the impact of MDA with IVM plus dihydroartemisinin-piperaquine (DP) on malaria transmission in an area with high coverage of malaria control interventions. METHODS The study is a cluster randomized trial in the Upper River Region of The Gambia and included 32 villages (16 control and 16 intervention). A buffer zone of ~2 km was created around all intervention clusters. MDA with IVM plus DP was implemented in all intervention villages and the buffer zones; control villages received standard malaria interventions according to the Gambian National Malaria Control Program plans. RESULTS The MDA campaigns were carried out from August to October 2018 for the first year and from July to September 2019 for the second year. Statistical analysis will commence once the database is completed, cleaned, and locked. CONCLUSIONS This is the first cluster randomized clinical trial of MDA with IVM plus DP. The results will provide evidence on the impact of MDA with IVM plus DP on malaria transmission. TRIAL REGISTRATION ClinicalTrials.gov NCT03576313; https://clinicaltrials.gov/ct2/show/NCT03576313. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/20904.
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Affiliation(s)
- Edgard Diniba Dabira
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Harouna M Soumare
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Steven W Lindsay
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Bakary Conteh
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Fatima Ceesay
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - John Bradley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Christian Kositz
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Balla Kandeh
- National Malaria Control Program, The Gambia, Banjul, Gambia
| | - Alexandra E Fehr
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Vrije Universiteit Amsterdam, Athena Institute, Amsterdam, Netherlands
| | - Claudia Nieto-Sanchez
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Joan Muela Ribera
- Medial Anthropology Research Center, Universitat Rovira i Virgili, Tarragona, Spain
| | - Koen Peeters Grietens
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Menno Roderick Smit
- Amsterdam Centre for Global Child Health, Emma Children's Hospital, Amsterdam University Medical Centres, Amsterdam, The Netherlands, Amsterdam, Netherlands
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Radboud University Medical Centre, Nijmegen, Netherlands
| | - Jane Achan
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
| | - Umberto D'Alessandro
- Medical Research Council Unit Gambia, London School of Hygiene and Tropical Medicine, Banjul, Gambia
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15
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Wu L, Mwesigwa J, Affara M, Bah M, Correa S, Hall T, Singh SK, Beeson JG, Tetteh KKA, Kleinschmidt I, D’Alessandro U, Drakeley C. Sero-epidemiological evaluation of malaria transmission in The Gambia before and after mass drug administration. BMC Med 2020; 18:331. [PMID: 33183292 PMCID: PMC7664049 DOI: 10.1186/s12916-020-01785-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 09/16/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND As The Gambia aims to achieve malaria elimination by 2030, serological assays are a useful surveillance tool to monitor trends in malaria incidence and evaluate community-based interventions. METHODS Within a mass drug administration (MDA) study in The Gambia, where reduced malaria infection and clinical disease were observed after the intervention, a serological sub-study was conducted in four study villages. Spatio-temporal variation in transmission was measured with a panel of recombinant Pf antigens on a multiplexed bead-based assay. Village-level antibody levels were quantified as under-15 sero-prevalence, sero-conversion rates, and age-adjusted antibody acquisition rates. Antibody levels prior to MDA were assessed for association with persistent malaria infection after community chemoprophylaxis. RESULTS Seasonal changes in antibodies to Etramp5.Ag1 were observed in children under 15 years in two transmission settings-the West Coast and Upper River Regions (4.32% and 31.30% Pf prevalence, respectively). At the end of the malaria season, short-lived antibody responses to Etramp5.Ag1, GEXP18, HSP40.Ag1, EBA175 RIII-V, and Rh2.2030 were lower amongst 1-15 year olds in the West Coast compared to the Upper River, reflecting known differences in transmission. Prior to MDA, individuals in the top 50th percentile of antibody levels had two-fold higher odds of clinical malaria during the transmission season, consistent with previous findings from the Malaria Transmission Dynamics Study, where individuals infected before the implementation of MDA had two-fold higher odds of re-infection post-MDA. CONCLUSIONS Serological markers can serve dual functions as indicators of malaria exposure and incidence. By monitoring age-specific sero-prevalence, the magnitude of age-stratified antibody levels, or identifying groups of individuals with above-average antibody responses, these antigens have the potential to complement conventional malaria surveillance tools. Further studies, particularly cluster randomised trials, can help establish standardised serological protocols to reliably measure transmission across endemic settings.
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Affiliation(s)
- Lindsey Wu
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
| | - Julia Mwesigwa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Muna Affara
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Arusha, Tanzania
| | - Mamadou Bah
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Simon Correa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Tom Hall
- St. George’s University of London (SGUL), London, SW17 0RE UK
| | - Susheel K. Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - James G. Beeson
- Burnet Institute, Melbourne, Victoria 3004 Australia
- Central Clinical School, Monash University, Melbourne, Victoria Australia
- Department of Medicine, University of Melbourne, Melbourne, Victoria Australia
| | - Kevin K. A. Tetteh
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
| | - Immo Kleinschmidt
- Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
- School of Pathology, Wits Institute for Malaria Research, Faculty of Health Science, University of Witwatersrand, Johannesburg, South Africa
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Chris Drakeley
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
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16
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Bennett A, Porter TR, Mwenda MC, Yukich JO, Finn TP, Lungu C, Silumbe K, Mambwe B, Chishimba S, Mulube C, Bridges DJ, Hamainza B, Slutsker L, Steketee RW, Miller JM, Eisele TP. A Longitudinal Cohort to Monitor Malaria Infection Incidence during Mass Drug Administration in Southern Province, Zambia. Am J Trop Med Hyg 2020; 103:54-65. [PMID: 32618245 PMCID: PMC7416973 DOI: 10.4269/ajtmh.19-0657] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Rigorous evidence of effectiveness is needed to determine where and when to apply mass drug administration (MDA) or focal MDA (fMDA) as part of a malaria elimination strategy. The Zambia National Malaria Elimination Centre recently completed a community-randomized controlled trial in Southern Province to evaluate MDA and fMDA for transmission reduction. To assess the role of MDA and fMDA on infection incidence, we enrolled a longitudinal cohort for an 18-month period of data collection including monthly malaria parasite infection detection based on polymerase chain reaction and compared time to first infection and cumulative infection incidence outcomes across study arms using Cox proportional hazards and negative binomial models. A total of 2,026 individuals from 733 households were enrolled and completed sufficient follow-up for inclusion in analysis. Infection incidence declined dramatically across all study arms during the period of study, and MDA was associated with reduced risk of first infection (hazards ratio: 0.36; 95% CI: 0.16–0.80) and cumulative infection incidence during the first rainy season (first 5 months of follow-up) (incidence rate ratio: 0.34; 95% CI: 0.12–0.95). No significant effect was found for fMDA or for either arm over the full study period. Polymerase chain reaction infection status at baseline was strongly associated with follow-up infection. The short-term effects of MDA suggest it may be an impactful accelerator of transmission reduction in areas with high coverage of case management and vector control and should be considered as part of a malaria elimination strategy.
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Affiliation(s)
- Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California
| | - Travis R Porter
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Mulenga C Mwenda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Joshua O Yukich
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Timothy P Finn
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Chris Lungu
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Kafula Silumbe
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Brenda Mambwe
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Sandra Chishimba
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Conceptor Mulube
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Daniel J Bridges
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Busiku Hamainza
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | | | | | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Thomas P Eisele
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
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17
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Stresman G, Whittaker C, Slater HC, Bousema T, Cook J. Quantifying Plasmodium falciparum infections clustering within households to inform household-based intervention strategies for malaria control programs: An observational study and meta-analysis from 41 malaria-endemic countries. PLoS Med 2020; 17:e1003370. [PMID: 33119589 PMCID: PMC7595326 DOI: 10.1371/journal.pmed.1003370] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 09/11/2020] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Reactive malaria strategies are predicated on the assumption that individuals infected with malaria are clustered within households or neighbourhoods. Despite the widespread programmatic implementation of reactive strategies, little empirical evidence exists as to whether such strategies are appropriate and, if so, how they should be most effectively implemented. METHODS AND FINDINGS We collated 2 different datasets to assess clustering of malaria infections within households: (i) demographic health survey (DHS) data, integrating household information and patent malaria infection, recent fever, and recent treatment status in children; and (ii) data from cross-sectional and reactive detection studies containing information on the household and malaria infection status (patent and subpatent) of all-aged individuals. Both datasets were used to assess the odds of infections clustering within index households, where index households were defined based on whether they contained infections detectable through one of 3 programmatic strategies: (a) Reactive Case Detection (RACD) classifed by confirmed clinical cases, (b) Mass Screen and Treat (MSAT) classifed by febrile, symptomatic infections, and (c) Mass Test and Treat (MTAT) classifed by infections detectable using routine diagnostics. Data included 59,050 infections in 208,140 children under 7 years old (median age = 2 years, minimum = 2, maximum = 7) by microscopy/rapid diagnostic test (RDT) from 57 DHSs conducted between November 2006 and December 2018 from 23 African countries. Data representing 11,349 infections across all ages (median age = 22 years, minimum = 0.5, maximum = 100) detected by molecular tools in 132,590 individuals in 43 studies published between April 2006 and May 2019 in 20 African, American, Asian, and Middle Eastern countries were obtained from the published literature. Extensive clustering was observed-overall, there was a 20.40 greater (95% credible interval [CrI] 0.35-20.45; P < 0.001) odds of patent infections (according to the DHS data) and 5.13 greater odds (95% CI 3.85-6.84; P < 0.001) of molecularly detected infections (from the published literature) detected within households in which a programmatically detectable infection resides. The strongest degree of clustering identified by polymerase chain reaction (PCR)/ loop mediated isothermal amplification (LAMP) was observed using the MTAT strategy (odds ratio [OR] = 6.79, 95% CI 4.42-10.43) but was not significantly different when compared to MSAT (OR = 5.2, 95% CI 3.22-8.37; P-difference = 0.883) and RACD (OR = 4.08, 95% CI 2.55-6.53; P-difference = 0.29). Across both datasets, clustering became more prominent when transmission was low. However, limitations to our analysis include not accounting for any malaria control interventions in place, malaria seasonality, or the likely heterogeneity of transmission within study sites. Clustering may thus have been underestimated. CONCLUSIONS In areas where malaria transmission is peri-domestic, there are programmatic options for identifying households where residual infections are likely to be found. Combining these detection strategies with presumptively treating residents of index households over a sustained time period could contribute to malaria elimination efforts.
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Affiliation(s)
- Gillian Stresman
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Charlie Whittaker
- Department of Infectious Disease Epidemiology, London Centre for Neglected Tropical Disease Research and MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, United Kingdom
| | - Hannah C. Slater
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- PATH, Seattle, Washington, United States of America
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jackie Cook
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
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18
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Galatas B, Saúte F, Martí-Soler H, Guinovart C, Nhamussua L, Simone W, Munguambe H, Hamido C, Montañà J, Muguande O, Maartens F, Luis F, Paaijmans K, Mayor A, Bassat Q, Menéndez C, Macete E, Rabinovich R, Alonso PL, Candrinho B, Aide P. A multiphase program for malaria elimination in southern Mozambique (the Magude project): A before-after study. PLoS Med 2020; 17:e1003227. [PMID: 32797101 PMCID: PMC7428052 DOI: 10.1371/journal.pmed.1003227] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/17/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Malaria eradication remains the long-term vision of the World Health Organization (WHO). However, whether malaria elimination is feasible in areas of stable transmission in sub-Saharan Africa with currently available tools remains a subject of debate. This study aimed to evaluate a multiphased malaria elimination project to interrupt Plasmodium falciparum malaria transmission in a rural district of southern Mozambique. METHODS AND FINDINGS A before-after study was conducted between 2015 and 2018 in the district of Magude, with 48,448 residents living in 10,965 households. Building on an enhanced surveillance system, two rounds of mass drug administrations (MDAs) per year over two years (phase I, August 2015-2017), followed by one year of reactive focal mass drug administrations (rfMDAs) (phase II, September 2017-June 2018) were deployed with annual indoor residual spraying (IRS), programmatically distributed long-lasting insecticidal nets (LLINs), and standard case management. The four MDA rounds covered 58%-72% of the population, and annual IRS reported coverage was >70%. Yearly parasite surveys and routine surveillance data were used to monitor the primary outcomes of the study-malaria prevalence and incidence-at baseline and annually since the onset of the project. Parasite prevalence by rapid diagnostic test (RDT) declined from 9.1% (95% confidence interval [CI] 7.0-11.8) in May 2015 to 2.6% (95% CI 2.0-3.4), representing a 71.3% (95% CI 71.1-71.4, p < 0.001) reduction after phase I, and to 1.4% (95% CI 0.9-2.2) after phase II. This represented an 84.7% (95% CI 81.4-87.4, p < 0.001) overall reduction in all-age prevalence. Case incidence fell from 195 to 75 cases per 1,000 during phase I (61.5% reduction) and to 67 per 1,000 during phase II (65.6% overall reduction). Interrupted time series (ITS) analysis was used to estimate the level and trend change in malaria cases associated with the set of project interventions and the number of cases averted. Phase I interventions were associated with a significant immediate reduction in cases of 69.1% (95% CI 57.5-77.6, p < 0.001). Phase II interventions were not associated with a level or trend change. An estimated 76.7% of expected cases were averted throughout the project (38,369 cases averted of 50,005 expected). One malaria-associated inpatient death was observed during the study period. There were 277 mild adverse events (AEs) recorded through the passive pharmacovigilance system during the four MDA rounds. One serious adverse event (SAE) that resulted in death was potentially related to the drug. The study was limited by the incomplete coverage of interventions, the quality of the routine and cross-sectional data collected, and the restricted accuracy of ITS analysis with a short pre-intervention period. CONCLUSION In this study, we observed that the interventions deployed during the Magude project fell short of interrupting P. falciparum transmission with the coverages achieved. While new tools and strategies may be required to eventually achieve malaria elimination in stable transmission areas of sub-Saharan Africa, this project showed that innovative mixes of interventions can achieve large reductions in disease burden, a necessary step in the pathway towards elimination. TRIAL REGISTRATION ClinicalTrials.gov NCT02914145.
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Affiliation(s)
- Beatriz Galatas
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- * E-mail:
| | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | | | | | - Lidia Nhamussua
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Wilson Simone
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | | | - Camilo Hamido
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Júlia Montañà
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Olinda Muguande
- Fundação para o Desenvolvimento da Comunidade, Maputo, Mozambique
| | | | - Fabião Luis
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Krijn Paaijmans
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- School of Life Sciences, Center for Evolution and Medicine, Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, United States of America
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Quique Bassat
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain
| | - Clara Menéndez
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Eusebio Macete
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- National Institute of Health, Ministry of Health, Maputo, Mozambique
| | - Regina Rabinovich
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Pedro L. Alonso
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Baltazar Candrinho
- National Malaria Control Program, Ministry of Health, Maputo, Mozambique
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- National Institute of Health, Ministry of Health, Maputo, Mozambique
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19
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Stresman G, Sepúlveda N, Fornace K, Grignard L, Mwesigwa J, Achan J, Miller J, Bridges DJ, Eisele TP, Mosha J, Lorenzo PJ, Macalinao ML, Espino FE, Tadesse F, Stevenson JC, Quispe AM, Siqueira A, Lacerda M, Yeung S, Sovannaroth S, Pothin E, Gallay J, Hamre KE, Young A, Lemoine JF, Chang MA, Phommasone K, Mayxay M, Landier J, Parker DM, Von Seidlein L, Nosten F, Delmas G, Dondorp A, Cameron E, Battle K, Bousema T, Gething P, D'Alessandro U, Drakeley C. Association between the proportion of Plasmodium falciparum and Plasmodium vivax infections detected by passive surveillance and the magnitude of the asymptomatic reservoir in the community: a pooled analysis of paired health facility and community data. THE LANCET. INFECTIOUS DISEASES 2020; 20:953-963. [PMID: 32277908 PMCID: PMC7391005 DOI: 10.1016/s1473-3099(20)30059-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/23/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Passively collected malaria case data are the foundation for public health decision making. However, because of population-level immunity, infections might not always be sufficiently symptomatic to prompt individuals to seek care. Understanding the proportion of all Plasmodium spp infections expected to be detected by the health system becomes particularly paramount in elimination settings. The aim of this study was to determine the association between the proportion of infections detected and transmission intensity for Plasmodium falciparum and Plasmodium vivax in several global endemic settings. METHODS The proportion of infections detected in routine malaria data, P(Detect), was derived from paired household cross-sectional survey and routinely collected malaria data within health facilities. P(Detect) was estimated using a Bayesian model in 431 clusters spanning the Americas, Africa, and Asia. The association between P(Detect) and malaria prevalence was assessed using log-linear regression models. Changes in P(Detect) over time were evaluated using data from 13 timepoints over 2 years from The Gambia. FINDINGS The median estimated P(Detect) across all clusters was 12·5% (IQR 5·3-25·0) for P falciparum and 10·1% (5·0-18·3) for P vivax and decreased as the estimated log-PCR community prevalence increased (adjusted odds ratio [OR] for P falciparum 0·63, 95% CI 0·57-0·69; adjusted OR for P vivax 0·52, 0·47-0·57). Factors associated with increasing P(Detect) included smaller catchment population size, high transmission season, improved care-seeking behaviour by infected individuals, and recent increases (within the previous year) in transmission intensity. INTERPRETATION The proportion of all infections detected within health systems increases once transmission intensity is sufficiently low. The likely explanation for P falciparum is that reduced exposure to infection leads to lower levels of protective immunity in the population, increasing the likelihood that infected individuals will become symptomatic and seek care. These factors might also be true for P vivax but a better understanding of the transmission biology is needed to attribute likely reasons for the observed trend. In low transmission and pre-elimination settings, enhancing access to care and improvements in care-seeking behaviour of infected individuals will lead to an increased proportion of infections detected in the community and might contribute to accelerating the interruption of transmission. FUNDING Wellcome Trust.
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Affiliation(s)
- Gillian Stresman
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK.
| | - Nuno Sepúlveda
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK; Centre of Statistics and Its Applications, University of Lisbon, Lisbon, Portugal
| | - Kimberly Fornace
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Lynn Grignard
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Julia Mwesigwa
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia; Department of Global Health, University of Antwerp, Antwerp, Belgium
| | - Jane Achan
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - John Miller
- 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
| | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Jacklin Mosha
- National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Pauline Joy Lorenzo
- Department of Parasitology, Research Institute for Tropical Medicine, Research Drive, Alabang, Muntinlupa, Metro Manila, Philippines
| | - Maria Lourdes Macalinao
- Department of Parasitology, Research Institute for Tropical Medicine, Research Drive, Alabang, Muntinlupa, Metro Manila, Philippines
| | - Fe Esperanza Espino
- Department of Parasitology, Research Institute for Tropical Medicine, Research Drive, Alabang, Muntinlupa, Metro Manila, Philippines
| | - Fitsum Tadesse
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Jennifer C Stevenson
- Macha Research Trust, Choma District, Zambia; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - André Siqueira
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil; Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil; Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Marcus Lacerda
- Fundacao de Medicine Tropical Dr. Heitor Viera Dourado, Manaus, Brazil; Institutos Nacionais de Ciencia e Technologia (INCT), Instituto Elimina, Manaus, Brazil
| | - Shunmay Yeung
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Emilie Pothin
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland; Clinton Health Access Initiative, Boston, MA, USA
| | - Joanna Gallay
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Karen E Hamre
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, USA; CDC Foundation, Atlanta, GA, USA
| | - Alyssa Young
- Clinton Health Access Initiative, Port-au-Prince, Haiti
| | - Jean Frantz Lemoine
- Programme National de Contrôle de la Malaria, Ministère de la Santé Publique et de la Population (MSPP), Port-au-Prince, Haiti
| | - Michelle A Chang
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, USA
| | - Koukeo Phommasone
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Institute of Research and Education Development, University of Health Sciences, Vientiane, Laos
| | - Jordi Landier
- Aix Marseille Univ, IRD, INSERM, SESSTIM, Marseille, France
| | - Daniel M Parker
- Department of Population Health and Disease Prevention and Department of Epidemiology, University of California, Irvine, CA, USA
| | - Lorenz Von Seidlein
- Oxford Tropical Medicine Research Unit, Mahidol University Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Francois Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Gilles Delmas
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Arjen Dondorp
- Oxford Tropical Medicine Research Unit, Mahidol University Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ewan Cameron
- Telethon Kids Institute, Perth Children's Hospital, Nedlands, WA, Australia; Curtin University, Bentley, WA, Australia
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Peter Gething
- Telethon Kids Institute, Perth Children's Hospital, Nedlands, WA, Australia; Curtin University, Bentley, WA, Australia
| | - Umberto D'Alessandro
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK; Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
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20
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Hsiang MS, Ntuku H, Roberts KW, Dufour MSK, Whittemore B, Tambo M, McCreesh P, Medzihradsky OF, Prach LM, Siloka G, Siame N, Gueye CS, Schrubbe L, Wu L, Scott V, Tessema S, Greenhouse B, Erlank E, Koekemoer LL, Sturrock HJW, Mwilima A, Katokele S, Uusiku P, Bennett A, Smith JL, Kleinschmidt I, Mumbengegwi D, Gosling R. Effectiveness of reactive focal mass drug administration and reactive focal vector control to reduce malaria transmission in the low malaria-endemic setting of Namibia: a cluster-randomised controlled, open-label, two-by-two factorial design trial. Lancet 2020; 395:1361-1373. [PMID: 32334702 PMCID: PMC7184675 DOI: 10.1016/s0140-6736(20)30470-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 01/23/2020] [Accepted: 02/25/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND In low malaria-endemic settings, screening and treatment of individuals in close proximity to index cases, also known as reactive case detection (RACD), is practised for surveillance and response. However, other approaches could be more effective for reducing transmission. We aimed to evaluate the effectiveness of reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) in the low malaria-endemic setting of Zambezi (Namibia). METHODS We did a cluster-randomised controlled, open-label trial using a two-by-two factorial design of 56 enumeration area clusters in the low malaria-endemic setting of Zambezi (Namibia). We randomly assigned these clusters using restricted randomisation to four groups: RACD only, rfMDA only, RAVC plus RACD, or rfMDA plus RAVC. RACD involved rapid diagnostic testing and treatment with artemether-lumefantrine and single-dose primaquine, rfMDA involved presumptive treatment with artemether-lumefantrine, and RAVC involved indoor residual spraying with pirimiphos-methyl. Interventions were administered within 500 m of index cases. To evaluate the effectiveness of interventions targeting the parasite reservoir in humans (rfMDA vs RACD), in mosquitoes (RAVC vs no RAVC), and in both humans and mosquitoes (rfMDA plus RAVC vs RACD only), an intention-to-treat analysis was done. For each of the three comparisons, the primary outcome was the cumulative incidence of locally acquired malaria cases. This trial is registered with ClinicalTrials.gov, number NCT02610400. FINDINGS Between Jan 1, 2017, and Dec 31, 2017, 55 enumeration area clusters had 1118 eligible index cases that led to 342 interventions covering 8948 individuals. The cumulative incidence of locally acquired malaria was 30·8 per 1000 person-years (95% CI 12·8-48·7) in the clusters that received rfMDA versus 38·3 per 1000 person-years (23·0-53·6) in the clusters that received RACD; 30·2 per 1000 person-years (15·0-45·5) in the clusters that received RAVC versus 38·9 per 1000 person-years (20·7-57·1) in the clusters that did not receive RAVC; and 25·0 per 1000 person-years (5·2-44·7) in the clusters that received rfMDA plus RAVC versus 41·4 per 1000 person-years (21·5-61·2) in the clusters that received RACD only. After adjusting for imbalances in baseline and implementation factors, the incidence of malaria was lower in clusters receiving rfMDA than in those receiving RACD (adjusted incidence rate ratio 0·52 [95% CI 0·16-0·88], p=0·009), lower in clusters receiving RAVC than in those that did not (0·48 [0·16-0·80], p=0·002), and lower in clusters that received rfMDA plus RAVC than in those receiving RACD only (0·26 [0·10-0·68], p=0·006). No serious adverse events were reported. INTERPRETATION In a low malaria-endemic setting, rfMDA and RAVC, implemented alone and in combination, reduced malaria transmission and should be considered as alternatives to RACD for elimination of malaria. FUNDING Novartis Foundation, Bill & Melinda Gates Foundation, and Horchow Family Fund.
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Affiliation(s)
- Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA; Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA.
| | - Henry Ntuku
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Kathryn W Roberts
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Mi-Suk Kang Dufour
- Division of Prevention Science, University of California San Francisco, San Francisco, CA, USA
| | - Brooke Whittemore
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Munyaradzi Tambo
- Multidisciplinary Research Centre, University of Namibia, Windhoek, Namibia
| | - Patrick McCreesh
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Oliver F Medzihradsky
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA; Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Lisa M Prach
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Griffith Siloka
- Zambezi Ministry of Health and Social Services, Katima, Namibia
| | - Noel Siame
- Zambezi Ministry of Health and Social Services, Katima, Namibia
| | - Cara Smith Gueye
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Leah Schrubbe
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Lindsey Wu
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Valerie Scott
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Sofonias Tessema
- Division of Experimental Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Bryan Greenhouse
- Division of Experimental Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Erica Erlank
- Wits Research Institute for Malaria, South African Medical Research Council Collaborating Centre for Multi-Disciplinary Research on Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Lizette L Koekemoer
- Wits Research Institute for Malaria, South African Medical Research Council Collaborating Centre for Multi-Disciplinary Research on Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Hugh J W Sturrock
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Agnes Mwilima
- Zambezi Ministry of Health and Social Services, Katima, Namibia
| | - Stark Katokele
- National Vector-Borne Diseases Control Programme, Namibia Ministry of Health and Social Services, Windhoek, Namibia
| | - Petrina Uusiku
- National Vector-Borne Diseases Control Programme, Namibia Ministry of Health and Social Services, Windhoek, Namibia
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Jennifer L Smith
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Immo Kleinschmidt
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Wits Research Institute for Malaria, South African Medical Research Council Collaborating Centre for Multi-Disciplinary Research on 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
| | - Davis Mumbengegwi
- Multidisciplinary Research Centre, University of Namibia, Windhoek, Namibia
| | - Roly Gosling
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA; Multidisciplinary Research Centre, University of Namibia, Windhoek, Namibia
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21
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Nsanzabana C. Strengthening Surveillance Systems for Malaria Elimination by Integrating Molecular and Genomic Data. Trop Med Infect Dis 2019; 4:E139. [PMID: 31816974 PMCID: PMC6958499 DOI: 10.3390/tropicalmed4040139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/05/2019] [Accepted: 11/28/2019] [Indexed: 12/20/2022] Open
Abstract
Unprecedented efforts in malaria control over the last 15 years have led to a substantial decrease in both morbidity and mortality in most endemic settings. However, these progresses have stalled over recent years, and resurgence may cause dramatic impact on both morbidity and mortality. Nevertheless, elimination efforts are currently going on with the objective of reducing malaria morbidity and mortality by 90% and malaria elimination in at least 35 countries by 2030. Strengthening surveillance systems is of paramount importance to reach those targets, and the integration of molecular and genomic techniques into routine surveillance could substantially improve the quality and robustness of data. Techniques such as polymerase chain reaction (PCR) and quantitative PCR (qPCR) are increasingly available in malaria endemic countries, whereas others such as sequencing are already available in a few laboratories. However, sequencing, especially next-generation sequencing (NGS), requires sophisticated infrastructure with adequate computing power and highly trained personnel for data analysis that require substantial investment. Different techniques will be required for different applications, and cost-effective planning must ensure the appropriate use of available resources. The development of national and sub-regional reference laboratories could help in minimizing the resources required in terms of equipment and trained staff. Concerted efforts from different stakeholders at national, sub-regional, and global level are needed to develop the required framework to establish and maintain these reference laboratories.
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Affiliation(s)
- Christian Nsanzabana
- Department of Medicine, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland; ; Tel.: +41-61-284-82-52
- University of Basel, P.O. Box, CH-4003 Basel, Switzerland
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22
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Parker DM, Tun STT, White LJ, Kajeechiwa L, Thwin MM, Landier J, Chaumeau V, Corbel V, Dondorp AM, von Seidlein L, White NJ, Maude RJ, Nosten F. Potential herd protection against Plasmodium falciparum infections conferred by mass antimalarial drug administrations. eLife 2019; 8:e41023. [PMID: 30990166 PMCID: PMC6467567 DOI: 10.7554/elife.41023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 03/25/2019] [Indexed: 11/13/2022] Open
Abstract
The global malaria burden has decreased over the last decade and many nations are attempting elimination. Asymptomatic malaria infections are not normally diagnosed or treated, posing a major hurdle for elimination efforts. One solution to this problem is mass drug administration (MDA), with success depending on adequate population participation. Here, we present a detailed spatial and temporal analysis of malaria episodes and asymptomatic infections in four villages undergoing MDA in Myanmar. In this study, individuals from neighborhoods with low MDA adherence had 2.85 times the odds of having a malaria episode post-MDA in comparison to those from high adherence neighborhoods, regardless of individual participation, suggesting a herd effect. High mosquito biting rates, living in a house with someone else with malaria, or having an asymptomatic malaria infection were also predictors of clinical episodes. Spatial clustering of non-adherence to MDA, even in villages with high overall participation, may frustrate elimination efforts.
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Affiliation(s)
- Daniel M Parker
- Department of Population Health and Disease PreventionUniversity of CaliforniaIrvineUnited States
| | - Sai Thein Than Tun
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
| | - Lisa J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
| | - Ladda Kajeechiwa
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
| | - May Myo Thwin
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
| | - Jordi Landier
- Institut de Recherche pour le DéveloppementUniversity of MontpellierMontpellierFrance
| | - Victor Chaumeau
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre Hospitalier Universitaire de MontpellierMontpellierFrance
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle IRD 224-CNRS 5290UM1-UM2, Institut de Recherche pour le Développement (IRD)University of MontpellierMontpellierFrance
| | - Vincent Corbel
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle IRD 224-CNRS 5290UM1-UM2, Institut de Recherche pour le Développement (IRD)University of MontpellierMontpellierFrance
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
| | - Lorenz von Seidlein
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
| | - Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
- Harvard TH Chan School of Public HealthHarvard UniversityHarvardUnited States
| | - François Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited kingdom
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityNakhon PathomThailand
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Resistance to Artemisinin Combination Therapies (ACTs): Do Not Forget the Partner Drug! Trop Med Infect Dis 2019; 4:tropicalmed4010026. [PMID: 30717149 PMCID: PMC6473515 DOI: 10.3390/tropicalmed4010026] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 01/30/2023] Open
Abstract
Artemisinin-based combination therapies (ACTs) have become the mainstay for malaria treatment in almost all malaria endemic settings. Artemisinin derivatives are highly potent and fast acting antimalarials; but they have a short half-life and need to be combined with partner drugs with a longer half-life to clear the remaining parasites after a standard 3-day ACT regimen. When introduced, ACTs were highly efficacious and contributed to the steep decrease of malaria over the last decades. However, parasites with decreased susceptibility to artemisinins have emerged in the Greater Mekong Subregion (GMS), followed by ACTs’ failure, due to both decreased susceptibility to artemisinin and partner drug resistance. Therefore, there is an urgent need to strengthen and expand current resistance surveillance systems beyond the GMS to track the emergence or spread of artemisinin resistance. Great attention has been paid to the spread of artemisinin resistance over the last five years, since molecular markers of decreased susceptibility to artemisinin in the GMS have been discovered. However, resistance to partner drugs is critical, as ACTs can still be effective against parasites with decreased susceptibility to artemisinins, when the latter are combined with a highly efficacious partner drug. This review outlines the different mechanisms of resistance and molecular markers associated with resistance to partner drugs for the currently used ACTs. Strategies to improve surveillance and potential solutions to extend the useful therapeutic lifespan of the currently available malaria medicines are proposed.
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