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El Moustapha I, Deida J, Dadina M, El Ghassem A, Begnoug M, Hamdinou M, Mint Lekweiry K, Ould Ahmedou Salem MS, Khalef Y, Semane A, Ould Brahim K, Briolant S, Bogreau H, Basco L, Ould Mohamed Salem Boukhary A. Changing epidemiology of Plasmodium vivax malaria in Nouakchott, Mauritania: a six-year (2015-2020) prospective study. Malar J 2023; 22:18. [PMID: 36650533 PMCID: PMC9843100 DOI: 10.1186/s12936-023-04451-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 01/10/2023] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Plasmodium vivax malaria is one of the major infectious diseases of public health concern in Nouakchott, the capital city of Mauritania and the biggest urban setting in the Sahara. The assessment of the current trends in malaria epidemiology is primordial in understanding the dynamics of its transmission and developing an effective control strategy. METHODS A 6 year (2015-2020) prospective study was carried out in Nouakchott. Febrile outpatients with a clinical suspicion of malaria presenting spontaneously at Teyarett Health Centre or the paediatric department of Mother and Children Hospital Centre were screened for malaria using a rapid diagnostic test, microscopic examination of Giemsa-stained blood films, and nested polymerase chain reaction. Data were analysed using Microsoft Excel and GraphPad Prism and InStat software. RESULTS Of 1760 febrile patients included in this study, 274 (15.5%) were malaria-positive by rapid diagnostic test, 256 (14.5%) were malaria-positive by microscopy, and 291 (16.5%) were malaria-positive by PCR. Plasmodium vivax accounted for 216 of 291 (74.2%) PCR-positive patients; 47 (16.1%) and 28 (9.6%) had P. falciparum monoinfection or P. vivax-P. falciparum mixed infection, respectively. During the study period, the annual prevalence of malaria declined from 29.2% in 2015 to 13.2% in 2019 and 2.1% in 2020 (P < 0.05). Malaria transmission was essentially seasonal, with a peak occurring soon after the rainy season (October-November), and P. vivax infections, but not P. falciparum infections, occurred at low levels during the rest of the year. The most affected subset of patient population was adult male white and black Moors. The decline in malaria prevalence was correlated with decreasing annual rainfall (r = 0.85; P = 0.03) and was also associated with better management of the potable water supply system. A large majority of included patients did not possess or did not use bed nets. CONCLUSIONS Control interventions based on prevention, diagnosis, and treatment should be reinforced in Nouakchott, and P. vivax-specific control measures, including chloroquine and 8-aminoquinolines (primaquine, tafenoquine) for treatment, should be considered to further improve the efficacy of interventions and aim for malaria elimination.
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Affiliation(s)
- Inejih El Moustapha
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Jemila Deida
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Mariem Dadina
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Abdellahi El Ghassem
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Mariem Begnoug
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Mariem Hamdinou
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Khadijetou Mint Lekweiry
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania ,Unité de Recherche Ressources Génétique et Environnement, Institut Supérieur d’Enseignement Technologique (ISET), Rosso, Mauritania
| | - Mohamed Salem Ould Ahmedou Salem
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Yacoub Khalef
- Department of Pediatrics, Mother and Children Hospital Centre, Centre Hospitalier Mère et Enfant (CHME), Nouakchott, Mauritania
| | - Amal Semane
- Teyarett Health Centre (Centre de Santé de Teyarett), Nouakchott, Mauritania
| | - Khyarhoum Ould Brahim
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania
| | - Sébastien Briolant
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France ,grid.483853.10000 0004 0519 5986IHU-Méditerranée Infection, Marseille, France ,grid.418221.cUnité de Parasitologie Entomologie, Département de Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées (IRBA), Marseille, France
| | - Hervé Bogreau
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France ,grid.483853.10000 0004 0519 5986IHU-Méditerranée Infection, Marseille, France ,grid.418221.cUnité de Parasitologie Entomologie, Département de Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées (IRBA), Marseille, France
| | - Leonardo Basco
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France ,grid.483853.10000 0004 0519 5986IHU-Méditerranée Infection, Marseille, France
| | - Ali Ould Mohamed Salem Boukhary
- grid.442613.60000 0000 8717 1355Unité de Recherche Génomes et Milieux (GEMI), Université de Nouakchott, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania ,grid.483853.10000 0004 0519 5986IHU-Méditerranée Infection, Marseille, France
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Xu Y, Dong Y, Deng Y, Huang H, Chen M, Liu Y, Wu J, Zhang C, Zheng W. Molecular identification of vivax malaria relapse patients in the Yunnan Province based on homology analysis of the Plasmodium vivax circumsporozoite protein gene. Parasitol Res 2023; 122:85-96. [PMID: 36334150 PMCID: PMC9816221 DOI: 10.1007/s00436-022-07700-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022]
Abstract
More than 85% of the malaria burden in the Yunnan Province is caused by imported vivax malaria, and Yunnan is also where the majority of vivax malaria patients are diagnosed in China. Timely removal of the infection sources of Plasmodium vivax and its breeding environment remains the key to eliminating the secondary transmission of imported malaria. To that end, blood samples were collected from cases diagnosed and revalidated as single species infection with P. vivax in the Yunnan Province from 2013 to 2020. Specifically, samples from vivax malaria patients with suspected relapses episodes were subjected to PCR amplification, product sequencing, and analysis of the P. vivax circumsporozoite protein (pvcsp) gene. In total, 77 suspected relapse patients were identified out of 2484 cases infected with P. vivax, with a total of 81 recurrent episodes. A total of 156 CDS (coding DNA sequence) chains were obtained through PCR amplification and sequencing of the pvcsp gene from 159 blood samples, 121 of which can be matched to the paired sequences of 59 vivax malaria patients with both primary attack and recurrent experience. Of the 59 pairs of pvcsp gene sequences, every one of 31 pairs showed only one haplotype and no variant sites (VS), meaning every two paired sequence was completely homologous. Every one of the remaining 28 paired sequences had two haplotypes but no length polymorphism, indicating that the paired sequences was "weakly heterologous" with no fragment insertions (or deletions). All 59 vivax malaria patients with recurrences were caused by the activation of P. vivax hypnozoites originated from the same population as the primary infection. The paired analysis of the similarity between high variant genes allowed the identification of relapse episodes caused by P. vivax homologous hypnozoites and also demonstrated pvcsp gene as one of the candidate molecular markers for tracing infection origin.
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Affiliation(s)
- Yanchun Xu
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China
| | - Ying Dong
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China.
| | - Yan Deng
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China
| | - Herong Huang
- Department of Basic Medical Sciences, Clinical College of Anhui Medical University, Hefei, 230031, China
| | - Mengni Chen
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China
| | - Yan Liu
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China
| | - Jing Wu
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China
| | - Canglin Zhang
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Yunnan Centre of Malaria Research, Pu'er, 665000, China
| | - Webi Zheng
- Center for Disease Control and Prevention, Baoshan, 678000, China.
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Mwamlima TG, Mwakasungula SM, Mkindi CG, Tambwe MM, Mswata SS, Mbwambo SG, Mboya MF, Draper SJ, Silk SE, Mpina MG, Vianney JM, Olotu AI. Understanding the role of serological and clinical data on assessing the dynamic of malaria transmission: a case study of Bagamoyo district, Tanzania. Pan Afr Med J 2022; 43:60. [PMID: 36578806 PMCID: PMC9755714 DOI: 10.11604/pamj.2022.43.60.35779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 09/01/2022] [Indexed: 12/30/2022] Open
Abstract
Introduction naturally acquired blood-stage malaria antibodies and malaria clinical data have been reported to be useful in monitoring malaria change over time and as a marker of malaria exposure. This study assessed the total immunoglobulin G (IgG) levels to Plasmodium falciparum schizont among infants (5-17 months), estimated malaria incidence using routine health facility-based surveillance data and predicted trend relation between anti-schizont antibodies and malaria incidence in Bagamoyo. Methods 252 serum samples were used for assessment of total IgG by enzyme-linked immunosorbent assay and results were expressed in arbitrary units (AU). 147/252 samples were collected in 2021 during a blood-stage malaria vaccine trial [ClinicalTrials.gov NCT04318002], and 105/252 were archived samples of malaria vaccine trial conducted in 2012 [ClinicalTrials.gov NCT00866619]. Malaria incidence was calculated from outpatient clinic data of malaria rapid test or blood smear positive results retrieved from District-Health-Information-Software-2 (DHIS2) between 2013 and 2020. Cross-sectional data from both studies were analysed using STATA version 14. Results this study demonstrated a decline in total anti-schizont IgG levels from 490.21AU in 2012 to 97.07AU in 2021 which was related to a fall in incidence from 58.25 cases/1000 person-year in 2013 to 14.28 cases/1000 person-year in 2020. We also observed a significant difference in incidence when comparing high and low malaria transmission areas and by gender. However, we did not observe differences when comparing total anti-schizont antibodies by gender and study year. Conclusion total anti-schizont antibody levels appear to be an important serological marker of exposure for assessing the dynamic of malaria transmission in infants living in malaria-endemic regions.
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Affiliation(s)
- Tunu Guntram Mwamlima
- Ifakara Health Institute, Bagamoyo, Tanzania
- Department of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
- Corresponding author: Tunu Guntram Mwamlima, Ifakara Health Institute, Bagamoyo, Tanzania.
| | | | | | | | | | | | | | - Simon John Draper
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | | | | | - John-Mary Vianney
- Department of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
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Meng FF, Xu Q, Chen JJ, Ji Y, Zhang WH, Fan ZW, Zhao GP, Jiang BG, Shi TX, Fang LQ, Liu W. A dataset of distribution and diversity of blood-sucking mites in China. Sci Data 2021; 8:204. [PMID: 34354081 PMCID: PMC8342612 DOI: 10.1038/s41597-021-00994-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 07/16/2021] [Indexed: 12/22/2022] Open
Abstract
Mite-borne diseases, such as scrub typhus and hemorrhagic fever with renal syndrome, present an increasing global public health concern. Most of the mite-borne diseases are caused by the blood-sucking mites. To present a comprehensive understanding of the distributions and diversity of blood-sucking mites in China, we derived information from peer-reviewed journal articles, thesis publications and books related to mites in both Chinese and English between 1978 and 2020. Geographic information of blood-sucking mites' occurrence and mite species were extracted and georeferenced at the county level. Standard operating procedures were applied to remove duplicates and ensure accuracy of the data. This dataset contains 6,443 records of mite species occurrences at the county level in China. This geographical dataset provides an overview of the species diversity and wide distributions of blood-sucking mites, and can potentially be used in distribution prediction of mite species and risk assessment of mite-borne diseases in China.
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Affiliation(s)
- Fan-Fei Meng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Qiang Xu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Jin-Jin Chen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Yang Ji
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Wen-Hui Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Zheng-Wei Fan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Guo-Ping Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Bao-Gui Jiang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Tao-Xing Shi
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Li-Qun Fang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
| | - Wei Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
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5
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Cai C, Hu Z, Yu X. Accelerator or Brake: Immune Regulators in Malaria. Front Cell Infect Microbiol 2020; 10:610121. [PMID: 33363057 PMCID: PMC7758250 DOI: 10.3389/fcimb.2020.610121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
Malaria is a life-threatening infectious disease, affecting over 250 million individuals worldwide each year, eradicating malaria has been one of the greatest challenges to public health for a century. Growing resistance to anti-parasitic therapies and lack of effective vaccines are major contributing factors in controlling this disease. However, the incomplete understanding of parasite interactions with host anti-malaria immunity hinders vaccine development efforts to date. Recent studies have been unveiling the complexity of immune responses and regulators against Plasmodium infection. Here, we summarize our current understanding of host immune responses against Plasmodium-derived components infection and mainly focus on the various regulatory mechanisms mediated by recent identified immune regulators orchestrating anti-malaria immunity.
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Affiliation(s)
- Chunmei Cai
- Research Center for High Altitude Medicine, School of Medical, Qinghai University, Xining, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Qinghai University, Xining, China
| | - Zhiqiang Hu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiao Yu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Lab of Single Cell Technology and Application, Southern Medical University, Guangzhou, China
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6
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Imdad K, Sahana M, Rana MJ, Haque I, Patel PP, Pramanik M. A district-level susceptibility and vulnerability assessment of the COVID-19 pandemic's footprint in India. Spat Spatiotemporal Epidemiol 2020; 36:100390. [PMID: 33509422 PMCID: PMC7648890 DOI: 10.1016/j.sste.2020.100390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/26/2020] [Accepted: 11/06/2020] [Indexed: 12/23/2022]
Abstract
Examines the spread of the COVID-19 pandemic in India in four separate time steps. Uses geospatial and geostatistical measure to identify viral hotspots and clusters. Analyses COVID-19′s correlates at the district level, eliciting detailed outputs. Gauges epidemiological susceptibility and socioeconomic vulnerability to COVID-19. Provides a framework for denoting districts where lockdown measures can be eased.
In this study, we trace the COVID-19 pandemic's footprint across India's districts. We identify its primary epicentres and the outbreak's imprint in India's hinterlands in four separate time-steps, signifying the different lockdown stages. We also identify hotspots and predict areas where the pandemic may spread next. Significant clusters in the country's western and northern parts pose risk, along with the threat of rising numbers in the east. We also perform epidemiological and socioeconomic susceptibility and vulnerability analyses, identifying resident populations that may be physiologically weaker, leading to a high incidence of cases and pinpoint regions that may report high fatalities due to ambient poor demographic and health-related factors. Districts with a high share of urban population and high population density face elevated COVID-19 risks. Aspirational districts have a higher magnitude of transmission and fatality. Discerning such locations can allow targeted resource allocation to combat the pandemic's next phase in India.
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Affiliation(s)
- Kashif Imdad
- Department of Geography, Pandit Prithi Nath PG College (affiliated to Chhatrapati Shahu Ji Maharaj University), 96/12, Mahatma Gandhi Marg, Kanpur 208001, Uttar Pradesh, India.
| | - Mehebub Sahana
- School of Environment, Education and Development, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
| | - Md Juel Rana
- Centre for the Study of Regional Development, School of Social Sciences, Jawaharlal Nehru University, New Delhi 110067, India; International Institute for Population Sciences, Mumbai 400088, India.
| | - Ismail Haque
- Centre for the Study of Regional Development, School of Social Sciences, Jawaharlal Nehru University, New Delhi 110067, India; Indian Council for Research on International Economic Relations (ICRIER) Plot No. 16-17, Sector-6, Pushp Vihar Institutional Area, Saket, New Delhi 110017, India.
| | - Priyank Pravin Patel
- Department of Geography, Presidency University, 86/1, College Street, Kolkata 700073, West Bengal, India.
| | - Malay Pramanik
- Department of Development and Sustainability, School of Environment, Resources and Development, Asian Institute of Technology (AIT), PO. Box 4, Klong Luang, Pathumthani 12120, Thailand; Centre of International Politics, Organization, and Disarmament, School of International Studies, Jawaharlal Nehru University, New Delhi 110067, India.
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7
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Sutanto I, Kosasih A, Elyazar IRF, Simanjuntak DR, Larasati TA, Dahlan MS, Wahid I, Mueller I, Koepfli C, Kusriastuti R, Surya A, Laihad FJ, Hawley WA, Collins FH, Baird JK, Lobo NF. Negligible Impact of Mass Screening and Treatment on Mesoendemic Malaria Transmission at West Timor in Eastern Indonesia: A Cluster-Randomized Trial. Clin Infect Dis 2019; 67:1364-1372. [PMID: 29579195 PMCID: PMC6186863 DOI: 10.1093/cid/ciy231] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 03/21/2018] [Indexed: 01/09/2023] Open
Abstract
Background Mass screening and treatment (MST) aims to reduce malaria risk in communities by identifying and treating infected persons without regard to illness. Methods A cluster-randomized trial evaluated malaria incidence with and without MST. Clusters were randomized to 3, 2, or no MST interventions: MST3, 6 clusters (156 households/670 individuals); MST2, 5 clusters (89 households/423 individuals); and MST0, 5 clusters (174 households/777 individuals). All clusters completed the study with 14 residents withdrawing. In a cohort of 324 schoolchildren (MST3, n = 124; MST2, n = 57; MST0, n = 143) negative by microscopy at enrollment, we evaluated the incidence density of malaria during 3 months of MST and 3 months following. The MST intervention involved community-wide expert malaria microscopic screening and standard therapy with dihydroartemisinin-piperaquine and primaquine for glucose-6 phosphate dehydrogenase–normal subjects. All blood examinations included polymerase chain reaction assays, which did not guide on-site treatment. Results The risk ratios for incidence density of microscopically patent malaria in MST3 or MST2 relative to that in MST0 clusters were 1.00 (95% confidence interval [CI], .53–1.91) and 1.22 (95% CI, .42–3.55), respectively. Similar results were obtained with molecular analysis and species-specific (P. falciparum and P. vivax) infections. Microscopically subpatent, untreated infections accounted for 72% of those infected. Conclusions Two or 3 rounds of MST within 3 months did not impact the force of anopheline mosquito-borne infection in these communities. The high rate of untreated microscopically subpatent infections likely explains the observed poor impact. Clinical Trials Registration NCT01878357.
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Affiliation(s)
- Inge Sutanto
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | - Ayleen Kosasih
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | | | - Deddy R Simanjuntak
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | - Tri A Larasati
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | | | - Isra Wahid
- Department of Parasitology, Faculty of Medicine, University of Hasanudin, Makasar, Indonesia
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Rita Kusriastuti
- Communicable Disease Control, Ministry of Health, Jakarta, Indonesia
| | - Asik Surya
- Communicable Disease Control, Ministry of Health, Jakarta, Indonesia
| | | | | | - Frank H Collins
- Eck Institute for Global Health, University of Notre Dame, Indiana
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Indonesia.,Center for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Indiana
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8
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Battle KE, Lucas TCD, Nguyen M, Howes RE, Nandi AK, Twohig KA, Pfeffer DA, Cameron E, Rao PC, Casey D, Gibson HS, Rozier JA, Dalrymple U, Keddie SH, Collins EL, Harris JR, Guerra CA, Thorn MP, Bisanzio D, Fullman N, Huynh CK, Kulikoff X, Kutz MJ, Lopez AD, Mokdad AH, Naghavi M, Nguyen G, Shackelford KA, Vos T, Wang H, Lim SS, Murray CJL, Price RN, Baird JK, Smith DL, Bhatt S, Weiss DJ, Hay SI, Gething PW. Mapping the global endemicity and clinical burden of Plasmodium vivax, 2000-17: a spatial and temporal modelling study. Lancet 2019; 394:332-343. [PMID: 31229233 PMCID: PMC6675736 DOI: 10.1016/s0140-6736(19)31096-7] [Citation(s) in RCA: 232] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/12/2019] [Accepted: 04/24/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND Plasmodium vivax exacts a significant toll on health worldwide, yet few efforts to date have quantified the extent and temporal trends of its global distribution. Given the challenges associated with the proper diagnosis and treatment of P vivax, national malaria programmes-particularly those pursuing malaria elimination strategies-require up to date assessments of P vivax endemicity and disease impact. This study presents the first global maps of P vivax clinical burden from 2000 to 2017. METHODS In this spatial and temporal modelling study, we adjusted routine malariometric surveillance data for known biases and used socioeconomic indicators to generate time series of the clinical burden of P vivax. These data informed Bayesian geospatial models, which produced fine-scale predictions of P vivax clinical incidence and infection prevalence over time. Within sub-Saharan Africa, where routine surveillance for P vivax is not standard practice, we combined predicted surfaces of Plasmodium falciparum with country-specific ratios of P vivax to P falciparum. These results were combined with surveillance-based outputs outside of Africa to generate global maps. FINDINGS We present the first high-resolution maps of P vivax burden. These results are combined with those for P falciparum (published separately) to form the malaria estimates for the Global Burden of Disease 2017 study. The burden of P vivax malaria decreased by 41·6%, from 24·5 million cases (95% uncertainty interval 22·5-27·0) in 2000 to 14·3 million cases (13·7-15·0) in 2017. The Americas had a reduction of 56·8% (47·6-67·0) in total cases since 2000, while South-East Asia recorded declines of 50·5% (50·3-50·6) and the Western Pacific regions recorded declines of 51·3% (48·0-55·4). Europe achieved zero P vivax cases during the study period. Nonetheless, rates of decline have stalled in the past five years for many countries, with particular increases noted in regions affected by political and economic instability. INTERPRETATION Our study highlights important spatial and temporal patterns in the clinical burden and prevalence of P vivax. Amid substantial progress worldwide, plateauing gains and areas of increased burden signal the potential for challenges that are greater than expected on the road to malaria elimination. These results support global monitoring systems and can inform the optimisation of diagnosis and treatment where P vivax has most impact. FUNDING Bill & Melinda Gates Foundation and the Wellcome Trust.
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Affiliation(s)
- Katherine E Battle
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Tim C D Lucas
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Michele Nguyen
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Rosalind E Howes
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Anita K Nandi
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Katherine A Twohig
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Daniel A Pfeffer
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Ewan Cameron
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Puja C Rao
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Daniel Casey
- Seattle & King County Public Health, Seattle, WA, USA
| | - Harry S Gibson
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Jennifer A Rozier
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | | | - Suzanne H Keddie
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Emma L Collins
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Joseph R Harris
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Carlos A Guerra
- Medical Care Development International, Silver Spring, MD, USA
| | - Michael P Thorn
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Donal Bisanzio
- Global Health Division, RTI International, Washington, DC, USA; Epidemiology and Public Health Division, School of Medicine, University of Nottingham, Nottingham, UK
| | - Nancy Fullman
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Chantal K Huynh
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Xie Kulikoff
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Michael J Kutz
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Alan D Lopez
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Ali H Mokdad
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Mohsen Naghavi
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Grant Nguyen
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | - Theo Vos
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Haidong Wang
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Stephen S Lim
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | - Ric N Price
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - J Kevin Baird
- Eijkman-Oxford Clinical Rearch Unit, Jakarta, Indonesia; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - David L Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | - Daniel J Weiss
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Simon I Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Peter W Gething
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK.
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9
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Weiss DJ, Lucas TCD, Nguyen M, Nandi AK, Bisanzio D, Battle KE, Cameron E, Twohig KA, Pfeffer DA, Rozier JA, Gibson HS, Rao PC, Casey D, Bertozzi-Villa A, Collins EL, Dalrymple U, Gray N, Harris JR, Howes RE, Kang SY, Keddie SH, May D, Rumisha S, Thorn MP, Barber R, Fullman N, Huynh CK, Kulikoff X, Kutz MJ, Lopez AD, Mokdad AH, Naghavi M, Nguyen G, Shackelford KA, Vos T, Wang H, Smith DL, Lim SS, Murray CJL, Bhatt S, Hay SI, Gething PW. Mapping the global prevalence, incidence, and mortality of Plasmodium falciparum, 2000-17: a spatial and temporal modelling study. Lancet 2019; 394:322-331. [PMID: 31229234 PMCID: PMC6675740 DOI: 10.1016/s0140-6736(19)31097-9] [Citation(s) in RCA: 228] [Impact Index Per Article: 45.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/12/2019] [Accepted: 04/24/2019] [Indexed: 01/26/2023]
Abstract
BACKGROUND Since 2000, the scale-up of malaria control interventions has substantially reduced morbidity and mortality caused by the disease globally, fuelling bold aims for disease elimination. In tandem with increased availability of geospatially resolved data, malaria control programmes increasingly use high-resolution maps to characterise spatially heterogeneous patterns of disease risk and thus efficiently target areas of high burden. METHODS We updated and refined the Plasmodium falciparum parasite rate and clinical incidence models for sub-Saharan Africa, which rely on cross-sectional survey data for parasite rate and intervention coverage. For malaria endemic countries outside of sub-Saharan Africa, we produced estimates of parasite rate and incidence by applying an ecological downscaling approach to malaria incidence data acquired via routine surveillance. Mortality estimates were derived by linking incidence to systematically derived vital registration and verbal autopsy data. Informed by high-resolution covariate surfaces, we estimated P falciparum parasite rate, clinical incidence, and mortality at national, subnational, and 5 × 5 km pixel scales with corresponding uncertainty metrics. FINDINGS We present the first global, high-resolution map of P falciparum malaria mortality and the first global prevalence and incidence maps since 2010. These results are combined with those for Plasmodium vivax (published separately) to form the malaria estimates for the Global Burden of Disease 2017 study. The P falciparum estimates span the period 2000-17, and illustrate the rapid decline in burden between 2005 and 2017, with incidence declining by 27·9% and mortality declining by 42·5%. Despite a growing population in endemic regions, P falciparum cases declined between 2005 and 2017, from 232·3 million (95% uncertainty interval 198·8-277·7) to 193·9 million (156·6-240·2) and deaths declined from 925 800 (596 900-1 341 100) to 618 700 (368 600-952 200). Despite the declines in burden, 90·1% of people within sub-Saharan Africa continue to reside in endemic areas, and this region accounted for 79·4% of cases and 87·6% of deaths in 2017. INTERPRETATION High-resolution maps of P falciparum provide a contemporary resource for informing global policy and malaria control planning, programme implementation, and monitoring initiatives. Amid progress in reducing global malaria burden, areas where incidence trends have plateaued or increased in the past 5 years underscore the fragility of hard-won gains against malaria. Efforts towards elimination should be strengthened in such areas, and those where burden remained high throughout the study period. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
- Daniel J Weiss
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Tim C D Lucas
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Michele Nguyen
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Anita K Nandi
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Donal Bisanzio
- Global Health Division, Research Triangle Institute International, Washington, DC, USA; Public Health Division, School of Medicine, University of Nottingham, Nottingham, UK
| | - Katherine E Battle
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Ewan Cameron
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Katherine A Twohig
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Daniel A Pfeffer
- Menzies School of Health Research, Charles Darwin University, Casuarina, NT, Australia
| | - Jennifer A Rozier
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Harry S Gibson
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Puja C Rao
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Daniel Casey
- Seattle and King County Public Health, Seattle, WA, USA
| | | | - Emma L Collins
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Ursula Dalrymple
- Public Health England, Department of Health and Social Care, London, UK
| | - Naomi Gray
- Instruct: An Integrated Structural Biology Infrastructure for Europe, Oxford, UK
| | - Joseph R Harris
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Rosalind E Howes
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Sun Yun Kang
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Suzanne H Keddie
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Daniel May
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Susan Rumisha
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Michael P Thorn
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Ryan Barber
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Nancy Fullman
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Chantal K Huynh
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Xie Kulikoff
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Michael J Kutz
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Alan D Lopez
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Ali H Mokdad
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Mohsen Naghavi
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Grant Nguyen
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | - Theo Vos
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Haidong Wang
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - David L Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Stephen S Lim
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | | | - Simon I Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Peter W Gething
- Malaria Atlas Project, Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK.
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10
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Zhang G, Zheng D, Tian Y, Li S. A dataset of distribution and diversity of ticks in China. Sci Data 2019; 6:105. [PMID: 31263100 PMCID: PMC6602924 DOI: 10.1038/s41597-019-0115-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/31/2019] [Indexed: 12/19/2022] Open
Abstract
While tick-borne zoonoses, such as Lyme disease and tick-borne encephalitis, present an increasing global concern, knowledge of their vectors' distribution remains limited, especially for China. In this paper, we present the first comprehensive dataset of known tick species and their distributions in China, derived from peer-reviewed literature published between 1960 and 2017. We searched for journal articles, conference papers and degree thesis published in both English and Chinese, extracted geographic information associated with tick occurrence, and applied quality-control procedures to remove duplicates and ensure accuracy. The dataset contains 5731 records of geo-referenced occurrences for 123 tick species distributed over 1141 locations distinguished at four levels of scale i.e., provincial, prefectural, county, and township and finer. The most frequently reported tick species include Haemaphysalis longicornis, Dermacentor silvarum, Ixodes persulcatus, Haemaphysalis conicinna, Rhipicephalus microplus, and Rhipicephalus sanguineus sensu lato. The geographical dataset provides an improved map of where ticks inhabit China and can be used for a variety of spatial analyses of ticks and the risk of zoonoses they transmit.
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Affiliation(s)
- Guanshi Zhang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Duo Zheng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Yuqin Tian
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Sen Li
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, P.R. China.
- Centre for Ecology & Hydrology, Wallingford, UK.
- Environmental Change Institute, University of Oxford, Oxford, UK.
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11
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Gowda DC, Wu X. Parasite Recognition and Signaling Mechanisms in Innate Immune Responses to Malaria. Front Immunol 2018; 9:3006. [PMID: 30619355 PMCID: PMC6305727 DOI: 10.3389/fimmu.2018.03006] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/05/2018] [Indexed: 12/20/2022] Open
Abstract
Malaria caused by the Plasmodium family of parasites, especially P.falciparum and P. vivax, is a major health problem in many countries in the tropical and subtropical regions of the world. The disease presents a wide array of systemic clinical conditions and several life-threatening organ pathologies, including the dreaded cerebral malaria. Like many other infectious diseases, malaria is an inflammatory response-driven disease, and positive outcomes to infection depend on finely tuned regulation of immune responses that efficiently clear parasites and allow protective immunity to develop. Immune responses initiated by the innate immune system in response to parasites play key roles both in protective immunity development and pathogenesis. Initial pro-inflammatory responses are essential for clearing infection by promoting appropriate cell-mediated and humoral immunity. However, elevated and prolonged pro-inflammatory responses owing to inappropriate cellular programming contribute to disease conditions. A comprehensive knowledge of the molecular and cellular mechanisms that initiate immune responses and how these responses contribute to protective immunity development or pathogenesis is important for developing effective therapeutics and/or a vaccine. Historically, in efforts to develop a vaccine, immunity to malaria was extensively studied in the context of identifying protective humoral responses, targeting proteins involved in parasite invasion or clearance. The innate immune response was thought to be non-specific. However, during the past two decades, there has been a significant progress in understanding the molecular and cellular mechanisms of host-parasite interactions and the associated signaling in immune responses to malaria. Malaria infection occurs at two stages, initially in the liver through the bite of a mosquito, carrying sporozoites, and subsequently, in the blood through the invasion of red blood cells by merozoites released from the infected hepatocytes. Soon after infection, both the liver and blood stage parasites are sensed by various receptors of the host innate immune system resulting in the activation of signaling pathways and production of cytokines and chemokines. These immune responses play crucial roles in clearing parasites and regulating adaptive immunity. Here, we summarize the knowledge on molecular mechanisms that underlie the innate immune responses to malaria infection.
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Affiliation(s)
- D Channe Gowda
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Xianzhu Wu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
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12
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Abstract
This paper summarises key advances and priorities since the 2011 presentation of the Malaria Eradication Research Agenda (malERA), with a focus on the combinations of intervention tools and strategies for elimination and their evaluation using modelling approaches. With an increasing number of countries embarking on malaria elimination programmes, national and local decisions to select combinations of tools and deployment strategies directed at malaria elimination must address rapidly changing transmission patterns across diverse geographic areas. However, not all of these approaches can be systematically evaluated in the field. Thus, there is potential for modelling to investigate appropriate 'packages' of combined interventions that include various forms of vector control, case management, surveillance, and population-based approaches for different settings, particularly at lower transmission levels. Modelling can help prioritise which intervention packages should be tested in field studies, suggest which intervention package should be used at a particular level or stratum of transmission intensity, estimate the risk of resurgence when scaling down specific interventions after local transmission is interrupted, and evaluate the risk and impact of parasite drug resistance and vector insecticide resistance. However, modelling intervention package deployment against a heterogeneous transmission background is a challenge. Further validation of malaria models should be pursued through an iterative process, whereby field data collected with the deployment of intervention packages is used to refine models and make them progressively more relevant for assessing and predicting elimination outcomes.
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13
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Thylur RP, Wu X, Gowda NM, Punnath K, Neelgund SE, Febbraio M, Gowda DC. CD36 receptor regulates malaria-induced immune responses primarily at early blood stage infection contributing to parasitemia control and resistance to mortality. J Biol Chem 2017; 292:9394-9408. [PMID: 28416609 DOI: 10.1074/jbc.m117.781294] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/12/2017] [Indexed: 12/31/2022] Open
Abstract
In malaria, CD36 plays several roles, including mediating parasite sequestration to host organs, phagocytic clearance of parasites, and regulation of immunity. Although the functions of CD36 in parasite sequestration and phagocytosis have been clearly defined, less is known about its role in malaria immunity. Here, to understand the function of CD36 in malaria immunity, we studied parasite growth, innate and adaptive immune responses, and host survival in WT and Cd36-/- mice infected with a non-lethal strain of Plasmodium yoelii Compared with Cd36-/- mice, WT mice had lower parasitemias and were resistant to death. At early but not at later stages of infection, WT mice had higher circulatory proinflammatory cytokines and lower anti-inflammatory cytokines than Cd36-/- mice. WT mice showed higher frequencies of proinflammatory cytokine-producing and lower frequencies of anti-inflammatory cytokine-producing dendritic cells (DCs) and natural killer cells than Cd36-/- mice. Cytokines produced by co-cultures of DCs from infected mice and ovalbumin-specific, MHC class II-restricted α/β (OT-II) T cells reflected CD36-dependent DC function. WT mice also showed increased Th1 and reduced Th2 responses compared with Cd36-/- mice, mainly at early stages of infection. Furthermore, in infected WT mice, macrophages and neutrophils expressed higher levels of phagocytic receptors and showed enhanced phagocytosis of parasite-infected erythrocytes than those in Cd36-/- mice in an IFN-γ-dependent manner. However, there were no differences in malaria-induced humoral responses between WT and Cd36-/- mice. Overall, the results show that CD36 plays a significant role in controlling parasite burden by contributing to proinflammatory cytokine responses by DCs and natural killer cells, Th1 development, phagocytic receptor expression, and phagocytic activity.
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Affiliation(s)
- Ramesh P Thylur
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Xianzhu Wu
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Nagaraj M Gowda
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Kishore Punnath
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Shivayogeeshwara E Neelgund
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Maria Febbraio
- the Department of Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - D Channe Gowda
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
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14
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Howes RE, Battle KE, Mendis KN, Smith DL, Cibulskis RE, Baird JK, Hay SI. Global Epidemiology of Plasmodium vivax. Am J Trop Med Hyg 2016; 95:15-34. [PMID: 27402513 PMCID: PMC5198891 DOI: 10.4269/ajtmh.16-0141] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/19/2016] [Indexed: 01/09/2023] Open
Abstract
Plasmodium vivax is the most widespread human malaria, putting 2.5 billion people at risk of infection. Its unique biological and epidemiological characteristics pose challenges to control strategies that have been principally targeted against Plasmodium falciparum Unlike P. falciparum, P. vivax infections have typically low blood-stage parasitemia with gametocytes emerging before illness manifests, and dormant liver stages causing relapses. These traits affect both its geographic distribution and transmission patterns. Asymptomatic infections, high-risk groups, and resulting case burdens are described in this review. Despite relatively low prevalence measurements and parasitemia levels, along with high proportions of asymptomatic cases, this parasite is not benign. Plasmodium vivax can be associated with severe and even fatal illness. Spreading resistance to chloroquine against the acute attack, and the operational inadequacy of primaquine against the multiple attacks of relapse, exacerbates the risk of poor outcomes among the tens of millions suffering from infection each year. Without strategies accounting for these P. vivax-specific characteristics, progress toward elimination of endemic malaria transmission will be substantially impeded.
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Affiliation(s)
- Rosalind E. Howes
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Katherine E. Battle
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Kamini N. Mendis
- Global Malaria Program, World Health Organization, Geneva, Switzerland
| | - David L. Smith
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, Maryland
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | | | - J. Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Simon I. Hay
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
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15
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Gething PW, Casey DC, Weiss DJ, Bisanzio D, Bhatt S, Cameron E, Battle KE, Dalrymple U, Rozier J, Rao PC, Kutz MJ, Barber RM, Huynh C, Shackelford KA, Coates MM, Nguyen G, Fraser MS, Kulikoff R, Wang H, Naghavi M, Smith DL, Murray CJL, Hay SI, Lim SS. Mapping Plasmodium falciparum Mortality in Africa between 1990 and 2015. N Engl J Med 2016; 375:2435-2445. [PMID: 27723434 PMCID: PMC5484406 DOI: 10.1056/nejmoa1606701] [Citation(s) in RCA: 185] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Malaria control has not been routinely informed by the assessment of subnational variation in malaria deaths. We combined data from the Malaria Atlas Project and the Global Burden of Disease Study to estimate malaria mortality across sub-Saharan Africa on a grid of 5 km2 from 1990 through 2015. METHODS We estimated malaria mortality using a spatiotemporal modeling framework of geolocated data (i.e., with known latitude and longitude) on the clinical incidence of malaria, coverage of antimalarial drug treatment, case fatality rate, and population distribution according to age. RESULTS Across sub-Saharan Africa during the past 15 years, we estimated that there was an overall decrease of 57% (95% uncertainty interval, 46 to 65) in the rate of malaria deaths, from 12.5 (95% uncertainty interval, 8.3 to 17.0) per 10,000 population in 2000 to 5.4 (95% uncertainty interval, 3.4 to 7.9) in 2015. This led to an overall decrease of 37% (95% uncertainty interval, 36 to 39) in the number of malaria deaths annually, from 1,007,000 (95% uncertainty interval, 666,000 to 1,376,000) to 631,000 (95% uncertainty interval, 394,000 to 914,000). The share of malaria deaths among children younger than 5 years of age ranged from more than 80% at a rate of death of more than 25 per 10,000 to less than 40% at rates below 1 per 10,000. Areas with high malaria mortality (>10 per 10,000) and low coverage (<50%) of insecticide-treated bed nets and antimalarial drugs included much of Nigeria, Angola, and Cameroon and parts of the Central African Republic, Congo, Guinea, and Equatorial Guinea. CONCLUSIONS We estimated that there was an overall decrease of 57% in the rate of death from malaria across sub-Saharan Africa over the past 15 years and identified several countries in which high rates of death were associated with low coverage of antimalarial treatment and prevention programs. (Funded by the Bill and Melinda Gates Foundation and others.).
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Affiliation(s)
- Peter W Gething
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Daniel C Casey
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Daniel J Weiss
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Donal Bisanzio
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Samir Bhatt
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Ewan Cameron
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Katherine E Battle
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Ursula Dalrymple
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Jennifer Rozier
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Puja C Rao
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Michael J Kutz
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Ryan M Barber
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Chantal Huynh
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Katya A Shackelford
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Matthew M Coates
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Grant Nguyen
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Maya S Fraser
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Rachel Kulikoff
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Haidong Wang
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Mohsen Naghavi
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - David L Smith
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Christopher J L Murray
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Simon I Hay
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
| | - Stephen S Lim
- From the Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford (P.W.G., D.J.W., D.B., E.C., K.E.B., U.D., J.R.), and the Department of Infectious Disease Epidemiology, Imperial College London, London (S.B.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (D.C.C., P.C.R., M.J.K., R.M.B., C.H., K.A.S., M.M.C., G.N., M.S.F., R.K., H.W., M.N., D.L.S., C.J.L.M., S.I.H., S.S.L.)
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Castro MC, Maheu-Giroux M, Chiyaka C, Singer BH. Malaria Incidence Rates from Time Series of 2-Wave Panel Surveys. PLoS Comput Biol 2016; 12:e1005065. [PMID: 27509368 PMCID: PMC4980052 DOI: 10.1371/journal.pcbi.1005065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/18/2016] [Indexed: 11/25/2022] Open
Abstract
Methodology to estimate malaria incidence rates from a commonly occurring form of interval-censored longitudinal parasitological data—specifically, 2-wave panel data—was first proposed 40 years ago based on the theory of continuous-time homogeneous Markov Chains. Assumptions of the methodology were suitable for settings with high malaria transmission in the absence of control measures, but are violated in areas experiencing fast decline or that have achieved very low transmission. No further developments that can accommodate such violations have been put forth since then. We extend previous work and propose a new methodology to estimate malaria incidence rates from 2-wave panel data, utilizing the class of 2-component mixtures of continuous-time Markov chains, representing two sub-populations with distinct behavior/attitude towards malaria prevention and treatment. Model identification, or even partial identification, requires context-specific a priori constraints on parameters. The method can be applied to scenarios of any transmission intensity. We provide an application utilizing data from Dar es Salaam, an area that experienced steady decline in malaria over almost five years after a larviciding intervention. We conducted sensitivity analysis to account for possible sampling variation in input data and model assumptions/parameters, and we considered differences in estimates due to submicroscopic infections. Results showed that, assuming defensible a priori constraints on model parameters, most of the uncertainty in the estimated incidence rates was due to sampling variation, not to partial identifiability of the mixture model for the case at hand. Differences between microscopy- and PCR-based rates depend on the transmission intensity. Leveraging on a method to estimate incidence rates from 2-wave panel data under any transmission intensity, and from the increasing availability of such data, there is an opportunity to foster further methodological developments, particularly focused on partial identifiability and the diversity of a priori parameter constraints associated with different human-ecosystem interfaces. As a consequence there can be more nuanced planning and evaluation of malaria control programs than heretofore. Incidence rates measure the transitions between the states of noninfected to infected per unit of time and per person at risk. Usually calculated from longitudinal observations, they provide an indication of how rapidly a disease develops in a population over time. In the context of malaria, longitudinal data on infection status are obtained through consecutive survey rounds, separated by a certain time interval. Depending on the length of the interval, some changes of infection status may be missed, and thus only uncensored information would be available. Methodology to calculate incidence rates from this type of data was first proposed in 1976, but its assumptions were not applicable to low transmission settings, particularly in the presence of control measures. No alternative methodology has been proposed in the past 40 years, limiting attempts to obtain estimates of incidence rates in the current scenario of declining malaria transmission worldwide. In this paper we address this gap and introduce new methodology to estimate malaria incidence rates from longitudinal data that can be applied to settings with any transmission level. We provide a complete example of the method, including sensitivity analysis, and an assessment of possible differences between data based on microscopy vs. PCR diagnostics. To facilitate replication and wide use of the method, we make available a programming code in R language and the example dataset.
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Affiliation(s)
- Marcia C. Castro
- Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
- * E-mail: (MCC); (BHS)
| | - Mathieu Maheu-Giroux
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Christinah Chiyaka
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Burton H. Singer
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail: (MCC); (BHS)
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17
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Dinzouna-Boutamba SD, Lee S, Son UH, Song SM, Yun HS, Joo SY, Kwak D, Rhee MH, Chung DI, Hong Y, Goo YK. Distribution of Antibodies Specific to the 19-kDa and 33-kDa Fragments of Plasmodium vivax Merozoite Surface Protein 1 in Two Pathogenic Strains Infecting Korean Vivax Malaria Patients. Osong Public Health Res Perspect 2016; 7:213-9. [PMID: 27635370 PMCID: PMC5014746 DOI: 10.1016/j.phrp.2016.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/23/2016] [Accepted: 05/30/2016] [Indexed: 11/04/2022] Open
Abstract
Objectives Plasmodium vivax merozoite surface protein 1 (PvMSP1) is the most intensively studied malaria vaccine candidate. Although high antibody response-inducing two C-terminal fragments of PvMSP1 (PvMSP1-19 and PvMSP1-42) are currently being developed as candidate malaria vaccine antigens, their high genetic diversity in various isolates is a major hurdle. The sequence polymorphism of PvMSP1 has been investigated; however, the humoral immune responses induced by different portions of this protein have not been evaluated in Korea. Methods Two fragments of PvMSP1 were selected for this study: (1) PvMSP1-19, which is genetically conserved; and (2) PvMSP1-33, which corresponds to a variable portion. For the latter, two representative strains, Sal 1 and Belem, were included. Thus, three recombinant proteins, PvMSP1-19, PvMSP1-33 Sal 1, and PvMSP1-33 Belem, were produced in Escherichia coli and then tested by enzyme-linked immunosorbent assays using sera from 221 patients with vivax malaria. Results Of the 221 samples, 198, 142, and 106 samples were seropositive for PvMSP1-19, PvMSP1-33 Sal 1, and PvMSP1-33 Belem, respectively. Although 100 samples were simultaneously seropositive for antibodies specific to all the recombinant proteins, 39 and six samples were respectively seropositive for antibodies specific to MSP1-33 Sal 1 and MSP1-33 Belem. Antibodies specific to PvMSP1-19 were the most prevalent. Conclusion Monitoring seroprevalence is essential for the selection of promising vaccine candidates as most of the antigenic proteins in P. vivax are highly polymorphic.
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Bhatt S, Weiss D, Cameron E, Bisanzio D, Mappin B, Dalrymple U, Battle K, Moyes C, Henry A, Eckhoff P, Wenger E, Briët O, Penny M, Smith T, Bennett A, Yukich J, Eisele T, Griffin J, Fergus C, Lynch M, Lindgren F, Cohen J, Murray C, Smith D, Hay S, Cibulskis R, Gething P. The effect of malaria control on Plasmodium falciparum in Africa between 2000 and 2015. Nature 2015; 526:207-211. [PMID: 26375008 PMCID: PMC4820050 DOI: 10.1038/nature15535] [Citation(s) in RCA: 1736] [Impact Index Per Article: 192.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 09/01/2015] [Indexed: 12/15/2022]
Abstract
Since the year 2000, a concerted campaign against malaria has led to unprecedented levels of intervention coverage across sub-Saharan Africa. Understanding the effect of this control effort is vital to inform future control planning. However, the effect of malaria interventions across the varied epidemiological settings of Africa remains poorly understood owing to the absence of reliable surveillance data and the simplistic approaches underlying current disease estimates. Here we link a large database of malaria field surveys with detailed reconstructions of changing intervention coverage to directly evaluate trends from 2000 to 2015, and quantify the attributable effect of malaria disease control efforts. We found that Plasmodium falciparum infection prevalence in endemic Africa halved and the incidence of clinical disease fell by 40% between 2000 and 2015. We estimate that interventions have averted 663 (542-753 credible interval) million clinical cases since 2000. Insecticide-treated nets, the most widespread intervention, were by far the largest contributor (68% of cases averted). Although still below target levels, current malaria interventions have substantially reduced malaria disease incidence across the continent. Increasing access to these interventions, and maintaining their effectiveness in the face of insecticide and drug resistance, should form a cornerstone of post-2015 control strategies.
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Affiliation(s)
- S. Bhatt
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - D.J. Weiss
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - E. Cameron
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - D. Bisanzio
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - B. Mappin
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - U. Dalrymple
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - K. Battle
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - C.L. Moyes
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - A. Henry
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - P.A. Eckhoff
- Institute for Disease Modeling, Intellectual Ventures, 1555 132nd Ave NE, Bellevue, WA 98005, USA
| | - E.A. Wenger
- Institute for Disease Modeling, Intellectual Ventures, 1555 132nd Ave NE, Bellevue, WA 98005, USA
| | - O. Briët
- Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. BOX 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. BOX 4001, Basel, Switzerland
| | - M.A. Penny
- Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. BOX 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. BOX 4001, Basel, Switzerland
| | - T.A. Smith
- Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. BOX 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, P.O. BOX 4001, Basel, Switzerland
| | - A. Bennett
- Malaria Elimination Initiative, University of California San Francisco, 500 Parnassus Ave, San Francisco, CA 94143, San Francisco, USA
| | - J. Yukich
- Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2200 New Orleans, LA 70112, USA
| | - T.P. Eisele
- Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2200 New Orleans, LA 70112, USA
| | - J.T. Griffin
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK
| | - C.A. Fergus
- Global Malaria Programme, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland
| | - M. Lynch
- Global Malaria Programme, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland
| | - F. Lindgren
- Department of Mathematical Sciences, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - J.M. Cohen
- Clinton Health Access Initiative, Boston, MA, USA
| | - C.L.J. Murray
- Institute for Health Metrics and Evaluation, 2301 Fifth Ave., Suite 600, Seattle, WA 98121, USA
| | - D.L. Smith
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
- Institute for Health Metrics and Evaluation, 2301 Fifth Ave., Suite 600, Seattle, WA 98121, USA
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD 20850, USA
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland 20892-2220, USA
| | - S.I. Hay
- Institute for Health Metrics and Evaluation, 2301 Fifth Ave., Suite 600, Seattle, WA 98121, USA
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland 20892-2220, USA
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - R.E. Cibulskis
- Global Malaria Programme, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland
| | - P.W. Gething
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
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19
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Defining the relationship between infection prevalence and clinical incidence of Plasmodium falciparum malaria. Nat Commun 2015; 6:8170. [PMID: 26348689 PMCID: PMC4569718 DOI: 10.1038/ncomms9170] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/24/2015] [Indexed: 01/08/2023] Open
Abstract
In many countries health system data remain too weak to accurately enumerate Plasmodium falciparum malaria cases. In response, cartographic approaches have been developed that link maps of infection prevalence with mathematical relationships to predict the incidence rate of clinical malaria. Microsimulation (or ‘agent-based') models represent a powerful new paradigm for defining such relationships; however, differences in model structure and calibration data mean that no consensus yet exists on the optimal form for use in disease-burden estimation. Here we develop a Bayesian statistical procedure combining functional regression-based model emulation with Markov Chain Monte Carlo sampling to calibrate three selected microsimulation models against a purpose-built data set of age-structured prevalence and incidence counts. This allows the generation of ensemble forecasts of the prevalence–incidence relationship stratified by age, transmission seasonality, treatment level and exposure history, from which we predict accelerating returns on investments in large-scale intervention campaigns as transmission and prevalence are progressively reduced. Mathematical models are used to predict malaria burden to inform disease control efforts. Here, Cameron et al. use Bayesian statistics to calibrate previous models against a data set of age-structured prevalence and incidence, generating stratified forecasts of the prevalence–incidence relationship.
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Battle KE, Cameron E, Guerra CA, Golding N, Duda KA, Howes RE, Elyazar IRF, Price RN, Baird JK, Reiner RC, Smith DL, Gething PW, Hay SI. Defining the relationship between Plasmodium vivax parasite rate and clinical disease. Malar J 2015; 14:191. [PMID: 25948111 PMCID: PMC4429942 DOI: 10.1186/s12936-015-0706-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 04/22/2015] [Indexed: 01/05/2023] Open
Abstract
Background Though essential to the development and evaluation of national malaria control programmes, precise enumeration of the clinical illness burden of malaria in endemic countries remains challenging where local surveillance systems are incomplete. Strategies to infer annual incidence rates from parasite prevalence survey compilations have proven effective in the specific case of Plasmodium falciparum, but have yet to be developed for Plasmodium vivax. Moreover, defining the relationship between P. vivax prevalence and clinical incidence may also allow levels of endemicity to be inferred for areas where the information balance is reversed, that is, incident case numbers are more widely gathered than parasite surveys; both applications ultimately facilitating cartographic estimates of P. vivax transmission intensity and its ensuring disease burden. Methods A search for active case detection surveys was conducted and the recorded incidence values were matched to local, contemporary parasite rate measures and classified to geographic zones of differing relapse phenotypes. A hierarchical Bayesian model was fitted to these data to quantify the relationship between prevalence and incidence while accounting for variation among relapse zones. Results The model, fitted with 176 concurrently measured P. vivax incidence and prevalence records, was a linear regression of the logarithm of incidence against the logarithm of age-standardized prevalence. Specific relationships for the six relapse zones where data were available were drawn, as well as a pooled overall relationship. The slope of the curves varied among relapse zones; zones with short predicted time to relapse had steeper slopes than those observed to contain long-latency relapse phenotypes. Conclusions The fitted relationships, along with appropriate uncertainty metrics, allow for estimates of clinical incidence of known confidence to be made from wherever P. vivax prevalence data are available. This is a prerequisite for cartographic-based inferences about the global burden of morbidity due to P. vivax, which will be used to inform control efforts. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0706-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katherine E Battle
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Ewan Cameron
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Carlos A Guerra
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA.
| | - Nick Golding
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK.
| | - Kirsten A Duda
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Rosalind E Howes
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Iqbal R F Elyazar
- Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No 69, Jakarta, Indonesia.
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No 69, Jakarta, Indonesia. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Robert C Reiner
- Indiana University School of Public Health, Bloomington, IN, USA. .,Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
| | - David L Smith
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK. .,Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA. .,Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
| | - Peter W Gething
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Simon I Hay
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK. .,Fogarty International Center, National Institutes of Health, Bethesda, MD, USA. .,Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA.
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