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Holla P, Bhardwaj J, Tran TM. Mature beyond their years: young children who escape detection of parasitemia despite living in settings of intense malaria transmission. Biochem Soc Trans 2024; 52:1025-1034. [PMID: 38752830 PMCID: PMC11209762 DOI: 10.1042/bst20230401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/18/2024]
Abstract
Despite having the highest risk of progressing to severe disease due to lack of acquired immunity, the youngest children living in areas of highly intense malaria transmission have long been observed to be infected at lower rates than older children. Whether this observation is due to reduced exposure to infectious mosquito bites from behavioral and biological factors, maternally transferred immunity, genetic factors, or enhanced innate immunity in the young child has intrigued malaria researchers for over half a century. Recent evidence suggests that maternally transferred immunity may be limited to early infancy and that the young child's own immune system may contribute to control of malarial symptoms early in life and prior to the development of more effective adaptive immunity. Prospective studies of active and passive detection of Plasmodium falciparum blood-stage infections have identified young children (<5 years old) who remain uninfected through a defined surveillance period despite living in settings of highly intense malaria transmission. Yet, little is known about the potential immunological basis for this 'aparasitemic' phenotype. In this review, we summarize the observational evidence for this phenotype in field studies and examine potential reasons why these children escape detection of parasitemia, covering factors that are either extrinsic or intrinsic to their developing immune system. We discuss the challenges of distinguishing malaria protection from lack of malaria exposure in field studies. We also identify gaps in our knowledge regarding cellular immunity in the youngest age group and propose directions that researchers may take to address these gaps.
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Affiliation(s)
- Prasida Holla
- Ryan White Center for Global Health and Pediatric Infectious Diseases, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
| | - Jyoti Bhardwaj
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
| | - Tuan M. Tran
- Ryan White Center for Global Health and Pediatric Infectious Diseases, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
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2
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Tebben K, Yirampo S, Coulibaly D, Koné AK, Laurens MB, Stucke EM, Dembélé A, Tolo Y, Traoré K, Niangaly A, Berry AA, Kouriba B, Plowe CV, Doumbo OK, Lyke KE, Takala-Harrison S, Thera MA, Travassos MA, Serre D. Gene expression analyses reveal differences in children's response to malaria according to their age. Nat Commun 2024; 15:2021. [PMID: 38448421 PMCID: PMC10918175 DOI: 10.1038/s41467-024-46416-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/26/2024] [Indexed: 03/08/2024] Open
Abstract
In Bandiagara, Mali, children experience on average two clinical malaria episodes per year. However, even in the same transmission area, the number of uncomplicated symptomatic infections, and their parasitemia, can vary dramatically among children. We simultaneously characterize host and parasite gene expression profiles from 136 Malian children with symptomatic falciparum malaria and examine differences in the relative proportion of immune cells and parasite stages, as well as in gene expression, associated with infection and or patient characteristics. Parasitemia explains much of the variation in host and parasite gene expression, and infections with higher parasitemia display proportionally more neutrophils and fewer T cells, suggesting parasitemia-dependent neutrophil recruitment and/or T cell extravasation to secondary lymphoid organs. The child's age also strongly correlates with variations in gene expression: Plasmodium falciparum genes associated with age suggest that older children carry more male gametocytes, while variations in host gene expression indicate a stronger innate response in younger children and stronger adaptive response in older children. These analyses highlight the variability in host responses and parasite regulation during P. falciparum symptomatic infections and emphasize the importance of considering the children's age when studying and treating malaria infections.
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Affiliation(s)
- Kieran Tebben
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Salif Yirampo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye K Koné
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Matthew B Laurens
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Emily M Stucke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ahmadou Dembélé
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Youssouf Tolo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Karim Traoré
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Andrea A Berry
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Christopher V Plowe
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Kirsten E Lyke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Shannon Takala-Harrison
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mahamadou A Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mark A Travassos
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA.
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3
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Hong HG, Gouveia MH, Ogwang MD, Kerchan P, Reynolds SJ, Tenge CN, Were PA, Kuremu RT, Wekesa WN, Masalu N, Kawira E, Kinyera T, Wang X, Zhou J, Leal TP, Otim I, Legason ID, Nabalende H, Dhudha H, Mumia M, Baker FS, Okusolubo T, Ayers LW, Bhatia K, Goedert JJ, Woo J, Manning M, Cole N, Luo W, Hicks B, Chagaluka G, Johnston WT, Mutalima N, Borgstein E, Liomba GN, Kamiza S, Mkandawire N, Mitambo C, Molyneux EM, Newton R, Hutchinson A, Yeager M, Adeyemo AA, Thein SL, Rotimi CN, Chanock SJ, Prokunina-Olsson L, Mbulaiteye SM. Sickle cell allele HBB-rs334(T) is associated with decreased risk of childhood Burkitt lymphoma in East Africa. Am J Hematol 2024; 99:113-123. [PMID: 38009642 PMCID: PMC10872868 DOI: 10.1002/ajh.27149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/30/2023] [Accepted: 10/23/2023] [Indexed: 11/29/2023]
Abstract
Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that significantly contributes to childhood cancer burden in sub-Saharan Africa. Plasmodium falciparum, which causes malaria, is geographically associated with BL, but the evidence remains insufficient for causal inference. Inference could be strengthened by demonstrating that mendelian genes known to protect against malaria-such as the sickle cell trait variant, HBB-rs334(T)-also protect against BL. We investigated this hypothesis among 800 BL cases and 3845 controls in four East African countries using genome-scan data to detect polymorphisms in 22 genes known to affect malaria risk. We fit generalized linear mixed models to estimate odds ratios (OR) and 95% confidence intervals (95% CI), controlling for age, sex, country, and ancestry. The ORs of the loci with BL and P. falciparum infection among controls were correlated (Spearman's ρ = 0.37, p = .039). HBB-rs334(T) was associated with lower P. falciparum infection risk among controls (OR = 0.752, 95% CI 0.628-0.9; p = .00189) and BL risk (OR = 0.687, 95% CI 0.533-0.885; p = .0037). ABO-rs8176703(T) was associated with decreased risk of BL (OR = 0.591, 95% CI 0.379-0.992; p = .00271), but not of P. falciparum infection. Our results increase support for the etiological correlation between P. falciparum and BL risk.
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Affiliation(s)
- Hyokyoung G. Hong
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - Mateus H. Gouveia
- Center for Research on Genomics & Global Health, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Martin D. Ogwang
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu, Uganda
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Patrick Kerchan
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- EMBLEM Study, Kuluva Hospital, Arua, Uganda
| | - Steven J. Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Pamela A. Were
- EMBLEM Study, Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Robert T. Kuremu
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
| | - Walter N. Wekesa
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
| | | | - Esther Kawira
- EMBLEM Study, Shirati Health, Education, and Development Foundation, Shirati, Tanzania
| | - Tobias Kinyera
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu, Uganda
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Xunde Wang
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USAs
| | - Jiefu Zhou
- Department of Statistics and Probability, Michigan State University, MI, USA
| | - Thiago Peixoto Leal
- Lerner Research Institute, Genomic Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Isaac Otim
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu, Uganda
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Ismail D. Legason
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- EMBLEM Study, Kuluva Hospital, Arua, Uganda
| | - Hadijah Nabalende
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu, Uganda
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Herry Dhudha
- EMBLEM Study, Bugando Medical Center, Mwanza, Tanzania
| | - Mediatrix Mumia
- EMBLEM Study, Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Francine S. Baker
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - Temiloluwa Okusolubo
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USAs
| | - Leona W. Ayers
- Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Kishor Bhatia
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - James J Goedert
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - Joshua Woo
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - Michelle Manning
- Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Nathan Cole
- Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Wen Luo
- Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Belynda Hicks
- Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - George Chagaluka
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Blantyre, Malawi
| | - W Thomas Johnston
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, UK
| | - Nora Mutalima
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, UK
- Cancer Epidemiology Unit, University of Oxford, Oxford, UK
| | - Eric Borgstein
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Blantyre, Malawi
| | - George N. Liomba
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Steve Kamiza
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Nyengo Mkandawire
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Blantyre, Malawi
| | | | - Elizabeth M. Molyneux
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Robert Newton
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York, UK
| | - Amy Hutchinson
- Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Meredith Yeager
- Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Adebowale A. Adeyemo
- Center for Research on Genomics & Global Health, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Swee Lay Thein
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USAs
| | - Charles N. Rotimi
- Center for Research on Genomics & Global Health, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Stephen J. Chanock
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - Ludmila Prokunina-Olsson
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | - Sam M. Mbulaiteye
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
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4
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Tebben K, Yirampo S, Coulibaly D, Koné A, Laurens M, Stucke E, Dembélé A, Tolo Y, Traoré K, Niangaly A, Berry A, Kouriba B, Plowe C, Doumbo O, Lyke K, Takala-Harrison S, Thera M, Travassos M, Serre D. Gene expression analyses reveal differences in children's response to malaria according to their age. RESEARCH SQUARE 2023:rs.3.rs-3487114. [PMID: 37961587 PMCID: PMC10635353 DOI: 10.21203/rs.3.rs-3487114/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In Bandiagara, Mali, children experience on average two clinical malaria episodes per season. However, even in the same transmission area, the number of uncomplicated symptomatic infections, and their parasitemia, vary dramatically among children. To examine the factors contributing to these variations, we simultaneously characterized the host and parasite gene expression profiles from 136 children with symptomatic falciparum malaria and analyzed the expression of 9,205 human and 2,484 Plasmodium genes. We used gene expression deconvolution to estimate the relative proportion of immune cells and parasite stages in each sample and to adjust the differential gene expression analyses. Parasitemia explained much of the variation in both host and parasite gene expression and revealed that infections with higher parasitemia had more neutrophils and fewer T cells, suggesting parasitemia-dependent neutrophil recruitment and/or T cell extravasation to secondary lymphoid organs. The child's age was also strongly correlated with gene expression variations. Plasmodium falciparum genes associated with age suggested that older children carried more male gametocytes, while host genes associated with age indicated a stronger innate response (through TLR and NLR signaling) in younger children and stronger adaptive immunity (through TCR and BCR signaling) in older children. These analyses highlight the variability in host responses and parasite regulation during P. falciparum symptomatic infections and emphasize the importance of considering the children's age when studying and treating malaria infections.
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Affiliation(s)
| | - Salif Yirampo
- Universite des Sciences des Techniques et des Technologies de Bamako
| | - Drissa Coulibaly
- Universite des Sciences des Techniques et des Technologies de Bamako
| | - Abdoulaye Koné
- Universite des Sciences des Techniques et des Technologies de Bamako
| | | | | | - Ahmadou Dembélé
- Universite des Sciences des Techniques et des Technologies de Bamako
| | - Youssouf Tolo
- Universite des Sciences des Techniques et des Technologies de Bamako
| | - Karim Traoré
- Universite des Sciences des Techniques et des Technologies de Bamako
| | - Ahmadou Niangaly
- Universite des Sciences des Techniques et des Technologies de Bamako
| | | | - Bourema Kouriba
- Universite des Sciences des Techniques et des Technologies de Bamako
| | | | - Ogobara Doumbo
- Universite des Sciences des Techniques et des Technologies de Bamako
| | | | | | - Mahamadou Thera
- Malaria Research and Training Centre-International Center for Excellence in Research (MRTC-ICER)
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5
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Tebben K, Yirampo S, Coulibaly D, Koné AK, Laurens MB, Stucke EM, Dembélé A, Tolo Y, Traoré K, Niangaly A, Berry AA, Kouriba B, Plowe CV, Doumbo OK, Lyke KE, Takala-Harrison S, Thera MA, Travassos MA, Serre D. Gene expression analyses reveal differences in children's response to malaria according to their age. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563751. [PMID: 37961701 PMCID: PMC10634788 DOI: 10.1101/2023.10.24.563751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In Bandiagara, Mali, children experience on average two clinical malaria episodes per season. However, even in the same transmission area, the number of uncomplicated symptomatic infections, and their parasitemia, vary dramatically among children. To examine the factors contributing to these variations, we simultaneously characterized the host and parasite gene expression profiles from 136 children with symptomatic falciparum malaria and analyzed the expression of 9,205 human and 2,484 Plasmodium genes. We used gene expression deconvolution to estimate the relative proportion of immune cells and parasite stages in each sample and to adjust the differential gene expression analyses. Parasitemia explained much of the variation in both host and parasite gene expression and revealed that infections with higher parasitemia had more neutrophils and fewer T cells, suggesting parasitemia-dependent neutrophil recruitment and/or T cell extravasation to secondary lymphoid organs. The child's age was also strongly correlated with gene expression variations. Plasmodium falciparum genes associated with age suggested that older children carried more male gametocytes, while host genes associated with age indicated a stronger innate response (through TLR and NLR signaling) in younger children and stronger adaptive immunity (through TCR and BCR signaling) in older children. These analyses highlight the variability in host responses and parasite regulation during P. falciparum symptomatic infections and emphasize the importance of considering the children's age when studying and treating malaria infections.
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Affiliation(s)
- Kieran Tebben
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine; Baltimore, USA
| | - Salif Yirampo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Abdoulaye K. Koné
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Matthew B. Laurens
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - Emily M. Stucke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - Ahmadou Dembélé
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Youssouf Tolo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Karim Traoré
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Andrea A. Berry
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Christopher V. Plowe
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Kirsten E. Lyke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - Shannon Takala-Harrison
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - Mahamadou A. Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies; Bamako, Mali
| | - Mark A. Travassos
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Baltimore, USA
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine; Baltimore, USA
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6
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Smith MR, Gbedande K, Johnson CM, Campbell LA, Onjiko RS, Domingo ND, Opata MM. Model of severe malaria in young mice suggests unique response of CD4 T cells. Parasite Immunol 2022; 44:e12952. [PMID: 36131528 PMCID: PMC9787679 DOI: 10.1111/pim.12952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 12/30/2022]
Abstract
Severe malaria occurs most in young children but is poorly understood due to the absence of a developmentally-equivalent rodent model to study the pathogenesis of the disease. Though functional and quantitative deficiencies in innate response and a biased T helper 1 (Th1) response are reported in newborn pups, there is little information available about this intermediate stage of the adaptive immune system in murine neonates. To fill this gap in knowledge, we have developed a mouse model of severe malaria in young mice using 15-day old mice (pups) infected with Plasmodium chabaudi. We observe similar parasite growth pattern in pups and adults, with a 60% mortality and a decrease in the growth rate of the surviving young mice. Using a battery of behavioral assays, we observed neurological symptoms in pups that do not occur in infected wildtype adults. CD4+ T cells were activated and differentiated to an effector T cell (Teff) phenotype in both adult and pups. However, there were relatively fewer and less terminally differentiated pup CD4+ Teff than adult Teff. Interestingly, despite less activation, the pup Teff expressed higher T-bet than adults' cells. These data suggest that Th1 cells are functional in pups during Plasmodium infection but develop slowly.
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Affiliation(s)
- Margaret R. Smith
- Department of Biology, College of Arts and SciencesAppalachian State UniversityBooneNorth CarolinaUSA,Present address:
Cancer Biology Ph.D. ProgramWake Forest College of MedicineWinston SalemNorth CarolinaUSA
| | - Komi Gbedande
- Division of Infectious Diseases, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Corey M. Johnson
- Department of Biology, College of Arts and SciencesAppalachian State UniversityBooneNorth CarolinaUSA
| | - Logan A. Campbell
- Department of Biology, College of Arts and SciencesAppalachian State UniversityBooneNorth CarolinaUSA
| | - Robert S. Onjiko
- Department of Biology, College of Arts and SciencesAppalachian State UniversityBooneNorth CarolinaUSA
| | - Nadia D. Domingo
- Division of Infectious Diseases, Department of Internal MedicineUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Michael M. Opata
- Department of Biology, College of Arts and SciencesAppalachian State UniversityBooneNorth CarolinaUSA
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7
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Chan JA, Loughland JR, de la Parte L, Okano S, Ssewanyana I, Nalubega M, Nankya F, Musinguzi K, Rek J, Arinaitwe E, Tipping P, Bourke P, Andrew D, Dooley N, SheelaNair A, Wines BD, Hogarth PM, Beeson JG, Greenhouse B, Dorsey G, Kamya M, Hartel G, Minigo G, Feeney M, Jagannathan P, Boyle MJ. Age-dependent changes in circulating Tfh cells influence development of functional malaria antibodies in children. Nat Commun 2022; 13:4159. [PMID: 35851033 PMCID: PMC9293980 DOI: 10.1038/s41467-022-31880-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 07/08/2022] [Indexed: 01/29/2023] Open
Abstract
T-follicular helper (Tfh) cells are key drivers of antibodies that protect from malaria. However, little is known regarding the host and parasite factors that influence Tfh and functional antibody development. Here, we use samples from a large cross-sectional study of children residing in an area of high malaria transmission in Uganda to characterize Tfh cells and functional antibodies to multiple parasites stages. We identify a dramatic re-distribution of the Tfh cell compartment with age that is independent of malaria exposure, with Th2-Tfh cells predominating in early childhood, while Th1-Tfh cell gradually increase to adult levels over the first decade of life. Functional antibody acquisition is age-dependent and hierarchical acquired based on parasite stage, with merozoite responses followed by sporozoite and gametocyte antibodies. Antibodies are boosted in children with current infection, and are higher in females. The children with the very highest antibody levels have increased Tfh cell activation and proliferation, consistent with a key role of Tfh cells in antibody development. Together, these data reveal a complex relationship between the circulating Tfh compartment, antibody development and protection from malaria.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
| | - Jessica R Loughland
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia.,Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia
| | | | - Satomi Okano
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Isaac Ssewanyana
- Infectious Diseases Research Collaboration, Kampala, Uganda.,London School of Hygiene and Tropical Medicine, London, UK
| | - Mayimuna Nalubega
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia.,Infectious Diseases Research Collaboration, Kampala, Uganda.,Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | | | | | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Peta Tipping
- Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia
| | - Peter Bourke
- Division of Medicine, Cairns Hospital, Manunda, QLD, Australia
| | - Dean Andrew
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nicholas Dooley
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia.,Griffith University, Brisbane, QLD, Australia
| | - Arya SheelaNair
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Bruce D Wines
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Clinical Pathology, The University of Melbourne, Parkville, VIC, Australia
| | - P Mark Hogarth
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Clinical Pathology, The University of Melbourne, Parkville, VIC, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia.,Department of Microbiology, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | | | - Grant Dorsey
- University of California San Francisco, San Francisco, CA, USA
| | - Moses Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Gunter Hartel
- QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Gabriela Minigo
- Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia.,College of Health and Human Sciences, Charles Darwin University, Darwin, NT, Australia
| | - Margaret Feeney
- University of California San Francisco, San Francisco, CA, USA
| | | | - Michelle J Boyle
- Burnet Institute, Melbourne, VIC, Australia. .,QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia. .,Global and Tropical Health Division, Menzies School of Health Research, Tiwi, Australia. .,Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia. .,Griffith University, Brisbane, QLD, Australia.
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8
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Oyong DA, Loughland JR, Soon MSF, Chan JA, Andrew D, Wines BD, Hogarth PM, Olver SD, Collinge AD, Varelias A, Beeson JG, Kenangalem E, Price RN, Anstey NM, Minigo G, Boyle MJ. Adults with Plasmodium falciparum malaria have higher magnitude and quality of circulating T-follicular helper cells compared to children. EBioMedicine 2022; 75:103784. [PMID: 34968760 PMCID: PMC8718734 DOI: 10.1016/j.ebiom.2021.103784] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 11/28/2021] [Accepted: 12/11/2021] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Protective malarial antibodies are acquired more rapidly in adults than children, independently of cumulative exposure, however the cellular responses mediating these differences are unknown. CD4 T-follicular helper (Tfh) cells have key roles in inducing antibodies, with Th2-Tfh cell activation associated with antibody development in malaria. Whether Tfh cell activation in malaria is age dependent is unknown and no studies have compared Tfh cell activation in children and adults with malaria. METHODS We undertook a comprehensive study of Tfh cells, along with B cells and antibody induction in children and adults with malaria. Activation and proliferation of circulating Tfh (cTfh) cell subsets was measured ex vivo and parasite-specific Tfh cell frequencies and functions studied with Activation Induced Marker (AIM) assays and intracellular cytokine staining. FINDINGS During acute malaria, the magnitude of cTfh cell activation was higher in adults than in children and occurred across all cTfh cell subsets in adults but was restricted only to the Th1-cTfh subset in children. Further, adults had higher levels of parasite-specific cTfh cells, and cTfh cells which produced more Th2-Tfh associated cytokine IL-4. Consistent with a role of higher Tfh cell activation in rapid immune development in adults, adults had higher activation of B cells during infection and higher induction of antibodies 7 and 28 days after malaria compared to children. INTERPRETATION Our data provide evidence that age impacts Tfh cell activation during malaria, and that these differences may influence antibody induction after treatment. Findings have important implications for vaccine development in children. FUNDING This word was supported by the National Health and Medical Research Council of Australia, Wellcome Trust, Charles Darwin University Menzies School of Health Research, Channel 7 Children's Research Foundation, and National Health Institute.
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Affiliation(s)
- Damian A Oyong
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia; Charles Darwin University, Darwin, NT, Australia
| | - Jessica R Loughland
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia; QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Megan S F Soon
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Jo-Anne Chan
- Burnet Institute, Melbourne, VIC, Australia; Department of Immunology, Central Clinical School, Monash University, VIC, Australia; Department of Medicine, University of Melbourne, VIC, Australia
| | - Dean Andrew
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Bruce D Wines
- Burnet Institute, Melbourne, VIC, Australia; Department of Immunology, Central Clinical School, Monash University, VIC, Australia; Department of Clinical Pathology, University of Melbourne, VIC, Australia
| | - P Mark Hogarth
- Burnet Institute, Melbourne, VIC, Australia; Department of Immunology, Central Clinical School, Monash University, VIC, Australia; Department of Clinical Pathology, University of Melbourne, VIC, Australia
| | - Stuart D Olver
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Alika D Collinge
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Antiopi Varelias
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; Faculty of Medicine, The University of Queensland, QLD, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, VIC, Australia; Department of Medicine, University of Melbourne, VIC, Australia; Department of Microbiology, Monash University, VIC, Australia
| | - Enny Kenangalem
- Timika Malaria Research Program, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia; District Health Authority, Timika, Papua, Indonesia
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
| | - Gabriela Minigo
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia; Charles Darwin University, Darwin, NT, Australia
| | - Michelle J Boyle
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia; QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; Burnet Institute, Melbourne, VIC, Australia; Faculty of Medicine, The University of Queensland, QLD, Australia.
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9
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Wallender E, Ali AM, Hughes E, Kakuru A, Jagannathan P, Muhindo MK, Opira B, Whalen M, Huang L, Duvalsaint M, Legac J, Kamya MR, Dorsey G, Aweeka F, Rosenthal PJ, Savic RM. Identifying an optimal dihydroartemisinin-piperaquine dosing regimen for malaria prevention in young Ugandan children. Nat Commun 2021; 12:6714. [PMID: 34795281 PMCID: PMC8602248 DOI: 10.1038/s41467-021-27051-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 10/29/2021] [Indexed: 12/01/2022] Open
Abstract
Intermittent preventive treatment (IPT) with dihydroartemisinin-piperaquine (DP) is highly protective against malaria in children, but is not standard in malaria-endemic countries. Optimal DP dosing regimens will maximize efficacy and reduce toxicity and resistance selection. We analyze piperaquine (PPQ) concentrations (n = 4573), malaria incidence data (n = 326), and P. falciparum drug resistance markers from a trial of children randomized to IPT with DP every 12 weeks (n = 184) or every 4 weeks (n = 96) from 2 to 24 months of age (NCT02163447). We use nonlinear mixed effects modeling to establish malaria protective PPQ levels and risk factors for suboptimal protection. Compared to DP every 12 weeks, DP every 4 weeks is associated with 95% protective efficacy (95% CI: 84-99%). A PPQ level of 15.4 ng/mL reduces the malaria hazard by 95%. Malnutrition reduces PPQ exposure. In simulations, we show that DP every 4 weeks is optimal across a range of transmission intensities, and age-based dosing improves malaria protection in young or malnourished children.
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Affiliation(s)
- Erika Wallender
- grid.266102.10000 0001 2297 6811Department of Clinical Pharmacy, University of California, San Francisco, San Francisco, CA USA
| | - Ali Mohamed Ali
- grid.266102.10000 0001 2297 6811Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA USA
| | - Emma Hughes
- grid.266102.10000 0001 2297 6811Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA USA
| | - Abel Kakuru
- grid.463352.5Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Prasanna Jagannathan
- grid.168010.e0000000419368956Department of Medicine, Stanford University, Palo Alto, CA USA
| | | | - Bishop Opira
- grid.463352.5Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Meghan Whalen
- grid.266102.10000 0001 2297 6811Department of Clinical Pharmacy, University of California, San Francisco, San Francisco, CA USA
| | - Liusheng Huang
- grid.266102.10000 0001 2297 6811Department of Clinical Pharmacy, University of California, San Francisco, San Francisco, CA USA
| | - Marvin Duvalsaint
- grid.266102.10000 0001 2297 6811Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Jenny Legac
- grid.266102.10000 0001 2297 6811Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Moses R. Kamya
- grid.463352.5Infectious Diseases Research Collaboration, Kampala, Uganda ,grid.11194.3c0000 0004 0620 0548Department of Medicine, Makerere University, Kampala, Uganda
| | - Grant Dorsey
- grid.266102.10000 0001 2297 6811Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Francesca Aweeka
- grid.266102.10000 0001 2297 6811Department of Clinical Pharmacy, University of California, San Francisco, San Francisco, CA USA
| | - Philip J. Rosenthal
- grid.266102.10000 0001 2297 6811Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Rada M. Savic
- grid.266102.10000 0001 2297 6811Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA USA
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10
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Peprah S, Ogwang MD, Kerchan P, Reynolds SJ, Tenge CN, Were PA, Kuremu RT, Wekesa WN, Masalu N, Kawira E, Otim I, Legason ID, Ayers LW, Bhatia K, Goedert JJ, Pfeiffer RM, Mbulaiteye SM. Inverse association of falciparum positivity with endemic Burkitt lymphoma is robust in analyses adjusting for pre-enrollment malaria in the EMBLEM case-control study. Infect Agent Cancer 2021; 16:40. [PMID: 34099001 PMCID: PMC8186042 DOI: 10.1186/s13027-021-00377-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/07/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Falciparum and endemic Burkitt lymphoma (eBL) are co-endemic in Africa, but the malaria experience in eBL patients is unknown. A lower prevalence of falciparum has been reported in eBL patients, but those results are anecdotally attributed to pre-enrollment anti-malaria treatment. METHODS We studied 677 eBL patients and 2920 community controls aged 0-15 years enrolled in six regions in Uganda, Tanzania, and Kenya during 2010-2016. Falciparum was diagnosed using thick blood film microscopy (TFM) and antigen-capture rapid diagnostic tests (RDTs). Guardians of the children answered a 40-item structured questionnaire about their child's pre-enrollment lifetime malaria history and treatment, demographics, socioeconomics, animal exposures, fevers, and hospitalizations. We utilized exploratory factor analysis to reduce the 40 questionnaire variables into six factors, including Inpatient malaria and Outpatient malaria factors that were surrogates of pre-enrollment anti-malaria treatment. The six factors accounted for 83-90% of the variance in the questionnaire data. We calculated odds ratios and 95% confidence intervals (OR 95% CI) of association of eBL with falciparum positivity, defined as positive both on TFM or RDTs, or only RDTs (indicative of recent infection) or TFM (indicative of current falciparum infection) versus no infection, using multivariable logistic regression, controlling for group of age (0-2, 3-5, 6-8, 9-11 and 12-15 years), sex, and study site and the afore-mentioned pre-enrollment factors. RESULTS The prevalence of falciparum infection was 25.6% in the eBL cases and 45.7% in community controls (aOR = 0.43, 95% CI: 0.40, 0.47; P < 0.0001). The results were similar for recent falciparum infection (6.9% versus 13.5%, aOR = 0.44, 95% CI: 0.38, 0.50; P < 0.0001) and current falciparum infection (18.7% versus 32.1%, aOR = 0.47, 95% CI: 0.43, 0.51; P < 0.0001). These aORs for any, recent and current falciparum infection did not change when we adjusted for pre-enrollment factors (aORs = 0.46, =0.44, and = 0.51, respectively) were significantly lower in stratified analysis for any infection in children < 5 years (aOR = 0.46; 95% CI: 0.29, 0.75) or ≥ 10 years (aOR = 0.47; 95% CI: 0.32, 0.71). CONCLUSION Our study results reduce support for pre-enrollment antimalaria treatment as a sole explanation for the observed lower falciparum prevalence in eBL cases and open a space to consider alternative immunology-based hypotheses.
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Affiliation(s)
- Sally Peprah
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Infections and Immunoepidemiology Branch, 9609 Medical Center Dr, Rm. 6E-118, MSC 3330, Bethesda, MD, 20892, USA
| | - Martin D Ogwang
- EMBLEM Study, St. Mary's Hospital, Lacor, Gulu & African Field Epidemiology Network, Kampala, Uganda
| | - Patrick Kerchan
- EMBLEM Study, Kuluva Hospital, Arua & African Field Epidemiology Network, Kampala, Uganda
| | - Steven J Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Constance N Tenge
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
- Moi Teaching and Referral Hospital (MTRH), Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Pamela A Were
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
- Moi Teaching and Referral Hospital (MTRH), Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Robert T Kuremu
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
- Moi Teaching and Referral Hospital (MTRH), Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Walter N Wekesa
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
- Moi Teaching and Referral Hospital (MTRH), Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | | | - Esther Kawira
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Isaac Otim
- EMBLEM Study, St. Mary's Hospital, Lacor, Gulu & African Field Epidemiology Network, Kampala, Uganda
| | - Ismail D Legason
- EMBLEM Study, Kuluva Hospital, Arua & African Field Epidemiology Network, Kampala, Uganda
| | - Leona W Ayers
- Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Infections and Immunoepidemiology Branch, 9609 Medical Center Dr, Rm. 6E-118, MSC 3330, Bethesda, MD, 20892, USA
| | - James J Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Infections and Immunoepidemiology Branch, 9609 Medical Center Dr, Rm. 6E-118, MSC 3330, Bethesda, MD, 20892, USA
| | - Ruth M Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Infections and Immunoepidemiology Branch, 9609 Medical Center Dr, Rm. 6E-118, MSC 3330, Bethesda, MD, 20892, USA
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Infections and Immunoepidemiology Branch, 9609 Medical Center Dr, Rm. 6E-118, MSC 3330, Bethesda, MD, 20892, USA.
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11
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Badiane AS, Ndiaye T, Thiaw AB, Binta DA, Diallo MA, Seck MC, Diongue K, Garba MN, Ndiaye M, Ndiaye D. High prevalence of asymptomatic Plasmodium infection in Bandafassi, South-East Senegal. Malar J 2021; 20:218. [PMID: 33980241 PMCID: PMC8117620 DOI: 10.1186/s12936-021-03746-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/22/2021] [Indexed: 01/12/2023] Open
Abstract
Background Malaria control and elimination strategies are based on levels of transmission that are usually determined by data collected from health facilities. In endemic areas, asymptomatic Plasmodium infection is thought to represent the majority of infections, though they are not diagnosed nor treated. Therefore, there might be an underestimation of the malaria reservoir, resulting in inadequate control strategies. In addition, these untreated asymptomatic Plasmodium infections maintain transmission, making it difficult or impossible to reach malaria elimination goals. Thus, the aim of this study was to determine the prevalence of asymptomatic Plasmodium infections in southeastern Senegal. Methods A cross sectional study was conducted among asymptomatic individuals (N = 122) living in the village of Andiel located in Bandafassi, Kédougou, which consisted of about 200 inhabitants during the malaria transmission season in late October 2019. For each individual without malaria-related symptoms and who consented to participate, a rapid diagnostic test (RDT) was performed in the field. Results were confirmed in the laboratory with photo-induced electron transfer (PET-PCR). Results Malaria prevalence was 70.3% by PET-PCR and 41.8% by RDT. During the same period, the health post of the area reported 49. 1% test positivity rate by RDT. The majority of the infected study population, 92.9%, was infected with a single species and 7.1% had two or three species of Plasmodium. Plasmodium falciparum was predominant and represented 90.2% of the infections, while 6.5% were due to Plasmodium ovale and 3.3% to Plasmodium malariae. 59.4% of children targeted for SMC (zero to ten years old) were infected. Conclusion In southeastern Senegal, where the transmission is the highest, malaria control strategies should address asymptomatic Plasmodium infections at the community level. The results suggest that this area could be eligible for mass drug administration. Moreover, non-falciparum species could be more common and its prevalence should be determined countrywide.
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Affiliation(s)
- Aida Sadikh Badiane
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University of Dakar, Dakar, Senegal. .,Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal.
| | - Tolla Ndiaye
- Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Alphonse Birane Thiaw
- Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Deme Awa Binta
- Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Mamadou Alpha Diallo
- Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Mame Cheikh Seck
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University of Dakar, Dakar, Senegal.,Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Khadim Diongue
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University of Dakar, Dakar, Senegal.,Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Mamane Nassirou Garba
- Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Mouhamadou Ndiaye
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University of Dakar, Dakar, Senegal.,Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
| | - Daouda Ndiaye
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University of Dakar, Dakar, Senegal.,Laboratory of Parasitology and Mycology, Aristide Le Dantec Hospital, Dakar, Senegal
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12
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Northrup GR, Qian L, Bruxvoort K, Marx FM, Whittles LK, Lewnard JA. Inference of Naturally Acquired Immunity Using a Self-matched Negative-Control Design. Epidemiology 2021; 32:168-178. [PMID: 33337670 PMCID: PMC7850593 DOI: 10.1097/ede.0000000000001305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 11/17/2020] [Indexed: 11/25/2022]
Abstract
Host adaptive immune responses may protect against infection or disease when a pathogen is repeatedly encountered. The hazard ratio of infection or disease, given previous infection, is typically sought to estimate the strength of protective immunity. However, variation in individual exposure or susceptibility to infection may introduce frailty bias, whereby a tendency for infections to recur among individuals with greater risk confounds the causal association between previous infection and susceptibility. We introduce a self-matched "case-only" inference method to control for unmeasured individual heterogeneity, making use of negative-control endpoints not attributable to the pathogen of interest. To control for confounding, this method compares event times for endpoints due to the pathogen of interest and negative-control endpoints during counterfactual risk periods, defined according to individuals' infection history. We derive a standard Mantel-Haenszel (matched) odds ratio conveying the effect of prior infection on time to recurrence. We compare performance of this approach to several proportional hazards modeling frameworks and estimate statistical power of the proposed strategy under various conditions. In an example application, we use the proposed method to reestimate naturally acquired protection against rotavirus gastroenteritis using data from previously published cohort studies. This self-matched negative-control design may present a flexible alternative to existing approaches for analyzing naturally acquired immunity, as well as other exposures affecting the distribution of recurrent event times.
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Affiliation(s)
- Graham R. Northrup
- From the Center for Computational Biology, College of Engineering, University of California, Berkeley, Berkeley, CA
| | - Lei Qian
- Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA
| | - Katia Bruxvoort
- Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA
| | - Florian M. Marx
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu Tuberculosis Centre, Stellenbosch University, Cape Town, South Africa
- DST-NRF South African Centre of Excellence and Epidemiological Modelling and Analysis, Stellenbosch University, Stellenbosch, South Africa
| | - Lilith K. Whittles
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
- NIHR Health Protection Research Unit in Modelling Methodology, School of Public Health, Imperial College London, London, United Kingdom
| | - Joseph A. Lewnard
- From the Center for Computational Biology, College of Engineering, University of California, Berkeley, Berkeley, CA
- Division of Epidemiology, School of Public Health, University of California, Berkeley, Berkeley, CA
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA
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13
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Potential functions of atypical memory B cells in Plasmodium-exposed individuals. Int J Parasitol 2020; 50:1033-1042. [PMID: 32987039 PMCID: PMC7666103 DOI: 10.1016/j.ijpara.2020.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/28/2020] [Accepted: 08/01/2020] [Indexed: 02/08/2023]
Abstract
Naturally acquired iummunity against clinical malaria is slow to develop, taking years of repeated exposure to parasites to acquire sufficiently broad and potent antibody responses. Increasing evidence suggests that Plasmodium infection and the resulting immune stimulation contribute to changes in the B cell compartment. In particular, accumulation of atypical memory B cells (atMBCs) is common in Plasmodium-exposed individuals. Similarities to B cell subsets present in other acute and chronic disease settings have provided insight into the development and potential function of these cells; however, their contribution to protection against malaria is still poorly understood. Here, we discuss recent findings that have increased our understanding of atMBCs and outline outstanding questions related to their function and development in the protective immune response to malaria.
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14
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Redmond LS, Ogwang MD, Kerchan P, Reynolds SJ, Tenge CN, Were PA, Kuremu RT, Masalu N, Kawira E, Otim I, Legason ID, Dhudha H, Ayers LW, Bhatia K, Goedert JJ, Mbulaiteye SM. Endemic Burkitt lymphoma: a complication of asymptomatic malaria in sub-Saharan Africa based on published literature and primary data from Uganda, Tanzania, and Kenya. Malar J 2020; 19:239. [PMID: 32718346 PMCID: PMC7385955 DOI: 10.1186/s12936-020-03312-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 06/30/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Endemic Burkitt lymphoma (eBL) is an aggressive B cell non-Hodgkin lymphoma associated with antigenic stimulation from Plasmodium falciparum malaria. Whether eBL risk is related to malaria parasite density is unknown. To address this issue, children with eBL, asymptomatic and clinical malaria, as a surrogate of malaria parasite density, were assessed. METHODS Malaria-related laboratory results (parasite density, haemoglobin, platelet count, and white cell count [WBC]) count) were compiled for 4019 eBL cases and 80,532 subjects evaluated for asymptomatic malaria or clinical malaria (severe malaria anaemia, hyperparasitaemia, cerebral malaria, malaria prostration, moderate malaria, and mild malaria) in 21 representative studies published in Africa (mostly East Africa) and 850 eBL cases and 2878 controls with primary data from the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) case-control study in Uganda, Tanzania, and Kenya. The average values of malaria-related laboratory results were computed by condition and trends across single-year age groups were assessed using regression and spline models. RESULTS Overall, malaria infection or malaria was diagnosed in 37,089 of children compiled from the literature. Children with eBL and asymptomatic parasitaemia/antigenaemia, but not those with clinical malaria, were closest in their mean age (age 7.1-7.2 vs. 7.4-9.8 years), haemoglobin level (10.0-10.4 vs. 11.7-12.3 g/dL), malaria parasite density (2800 vs. 1827-7780 parasites/µL), platelet count (347,000-353,000 vs. 244,000-306,000 platelets/µL), and WBC count (8180-8890 vs. 7100-7410 cells/µL). Parasite density in these two groups peaked between four to five years, then decreased steadily thereafter; conversely, haemoglobin showed a corresponding increase with age. Children with clinical malaria were markedly different: all had an average age below 5 years, had dramatically elevated parasite density (13,905-869,000 parasites/µL) and dramatically decreased platelet count (< 159,000 platelets/µL) and haemoglobin (< 7 g/dL). CONCLUSIONS eBL and asymptomatic parasitaemia/antigenaemia, but not clinical malaria, were the most similar conditions with respect to mean age and malaria-related laboratory results. These results suggest that children with asymptomatic parasitaemia/antigenaemia may be the population at risk of eBL.
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Affiliation(s)
- Lawrence S Redmond
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Martin D Ogwang
- EMBLEM Study, St. Mary's Hospital Lacor, Gulu, Uganda
- African Field Epidemiology Network, Kampala, Uganda
| | - Patrick Kerchan
- African Field Epidemiology Network, Kampala, Uganda
- EMBLEM Study, Kuluva Hospital Kuluva, Arua, Uganda
| | - Steven J Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Constance N Tenge
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
| | - Pamela A Were
- EMBLEM Study, Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
| | - Robert T Kuremu
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
| | | | - Esther Kawira
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Isaac Otim
- EMBLEM Study, St. Mary's Hospital Lacor, Gulu, Uganda
- African Field Epidemiology Network, Kampala, Uganda
| | - Ismail D Legason
- African Field Epidemiology Network, Kampala, Uganda
- EMBLEM Study, Kuluva Hospital Kuluva, Arua, Uganda
| | - Herry Dhudha
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Leona W Ayers
- Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - James J Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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15
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Peprah S, Ogwang MD, Kerchan P, Reynolds SJ, Tenge CN, Were PA, Kuremu RT, Wekesa WN, Sumba PO, Masalu N, Kawira E, Magatti J, Kinyera T, Otim I, Legason ID, Nabalende H, Dhudha H, Ally H, Genga IO, Mumia M, Ayers LW, Pfeiffer RM, Biggar RJ, Bhatia K, Goedert JJ, Mbulaiteye SM. Risk factors for Burkitt lymphoma in East African children and minors: A case-control study in malaria-endemic regions in Uganda, Tanzania and Kenya. Int J Cancer 2020; 146:953-969. [PMID: 31054214 PMCID: PMC6829037 DOI: 10.1002/ijc.32390] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 12/25/2022]
Abstract
Endemic Burkitt lymphoma (eBL) is the most common childhood cancer in sub-Saharan African countries, however, few epidemiologic studies have been undertaken and none attempted enrolling cases from multiple countries. We therefore conducted a population-based case-control study of eBL in children aged 0-15 years old in six regions in Northern Uganda, Northern Tanzania and Western Kenya, enrolling 862 suspected cases and 2,934 population controls (response rates 98.5-100%), and processing ~40,000 vials of samples using standardized protocols. Risk factor questionnaires were administered, and malaria period prevalence was measured using rapid diagnostic tests (RDTs). A total of 80.9% of the recruited cases were diagnosed as eBL; 61.4% confirmed by histology. Associations with eBL risk were computed using logistic regression models adjusted for relevant confounders. Associations common in at least two countries were emphasized. eBL risk was decreased with higher maternal income and paternal education and elevated with history of inpatient malaria treatment >12 months before enrollment. Reporting malaria-attributed fever up to 6 months before enrollment and malaria-RDT positivity at enrollment were associated with decreased eBL risk. Conversely, reporting exposure to mass malaria suppression programs (e.g., indoor residual insecticide) was associated with elevated risk. HIV seropositivity was associated with elevated eBL risk, but the relative impact was small. The study shows that it is feasible to conduct networked, multisite population-based studies of eBL in Africa. eBL was inversely associated with socioeconomic status, positively associated with inpatient malaria treatment 12 months ago and with living in areas targeted for malaria suppression, which support a role of malaria in eBL.
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Affiliation(s)
- Sally Peprah
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Martin D. Ogwang
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu & African Field Epidemiology Network, Kampala, Uganda
| | - Patrick Kerchan
- EMBLEM Study, Kuluva Hospital, Kuluva, Arua & African Field Epidemiology Network, Kampala, Uganda
| | - Steven J. Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Pamela A. Were
- EMBLEM Study, Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Robert T. Kuremu
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
| | - Walter N Wekesa
- EMBLEM Study, Moi University College of Health Sciences, Eldoret, Kenya
| | | | | | - Esther Kawira
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Josiah Magatti
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Tobias Kinyera
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu & African Field Epidemiology Network, Kampala, Uganda
| | - Isaac Otim
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu & African Field Epidemiology Network, Kampala, Uganda
| | - Ismail D. Legason
- EMBLEM Study, Kuluva Hospital, Kuluva, Arua & African Field Epidemiology Network, Kampala, Uganda
| | - Hadijah Nabalende
- EMBLEM Study, St. Mary’s Hospital, Lacor, Gulu & African Field Epidemiology Network, Kampala, Uganda
| | - Herry Dhudha
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Hillary Ally
- EMBLEM Study, Bugando Medical Center, Mwanza, Tanzania
| | - Isaiah O. Genga
- EMBLEM Study, Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Mediatrix Mumia
- EMBLEM Study, Academic Model Providing Access To Healthcare (AMPATH), Eldoret, Kenya
| | - Leona W. Ayers
- Department of Pathology, The Ohio State University, Columbus, Ohio, USA
| | - Ruth M. Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Robert J. Biggar
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - James J. Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Sam M. Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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16
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Peprah S, Tenge C, Genga IO, Mumia M, Were PA, Kuremu RT, Wekesa WN, Sumba PO, Kinyera T, Otim I, Legason ID, Biddle J, Reynolds SJ, Talisuna AO, Biggar RJ, Bhatia K, Goedert JJ, Pfeiffer RM, Mbulaiteye SM. A Cross-Sectional Population Study of Geographic, Age-Specific, and Household Risk Factors for Asymptomatic Plasmodium falciparum Malaria Infection in Western Kenya. Am J Trop Med Hyg 2019; 100:54-65. [PMID: 30457091 DOI: 10.4269/ajtmh.18-0481] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The burden of Plasmodium falciparum (Pf) malaria in Kenya is decreasing; however, it is still one of the top 10 causes of morbidity, particularly in regions of western Kenya. Between April 2015 and June 2016, we enrolled 965 apparently healthy children aged 0-15 years in former Nyanza and Western Provinces in Kenya to characterize the demographic, geographic, and household risk factors of asymptomatic malaria as part of an epidemiologic study to investigate the risk factors for endemic Burkitt lymphoma. The children were sampled using a stratified, multistage cluster sampling survey design. Malaria was assessed by rapid diagnostic test (RDT) and thick-film microscopy (TFM). Primary analyses of Pf malaria prevalence (pfPR) are based on RDT. Associations between weighted pfPR and potential risk factors were evaluated using logistic regression, accounting for the survey design. Plasmodium falciparum malaria prevalence was 36.0% (27.5%, 44.5%) by RDT and 22.3% (16.0%, 28.6%) by TFM. Plasmodium falciparum malaria prevalence was positively associated with living in the lake-endemic area (adjusted odds ratio [aOR] 3.46; 95% confidence interval [95% CI] 1.63, 7.37), paternal occupation as peasant farmer (aOR 1.87; 1.08, 3.26) or manual laborer (aOR 1.83; 1.00, 3.37), and keeping dogs (aOR 1.62; 0.98-2.69) or cows (aOR 1.52; 0.96-2.40) inside or near the household. Plasmodium falciparum malaria prevalence was inversely associated with indoor residual insecticide spraying (IRS) (aOR 0.44; 0.19, 1.01), having a household connected to electricity (aOR 0.47; 0.22, 0.98), and a household with two (aOR 0.45; 0.22, 0.93) or ≥ three rooms (aOR 0.41; 0.18, 0.93). We report high but geographically heterogeneous pfPR in children in western Kenya and significant associations with IRS and household-level socioeconomic factors.
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Affiliation(s)
- Sally Peprah
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | | | - Isaiah O Genga
- EMBLEM Study, Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
| | - Mediatrix Mumia
- EMBLEM Study, Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
| | - Pamela A Were
- EMBLEM Study, Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
| | | | | | | | - Tobias Kinyera
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Isaac Otim
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Ismail D Legason
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Joshua Biddle
- Stanford Hospitals and Clinics, University of Stanford, Pao Alto, California
| | - Steven J Reynolds
- National Institutes of Health/Uganda Project Entebbe, National Institute of Allergy and Infectious Diseases, Rockville, Maryland
| | - Ambrose O Talisuna
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
| | - Robert J Biggar
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - James J Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Ruth M Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
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17
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Greenhouse B, Smith DL, Rodríguez-Barraquer I, Mueller I, Drakeley CJ. Taking Sharper Pictures of Malaria with CAMERAs: Combined Antibodies to Measure Exposure Recency Assays. Am J Trop Med Hyg 2019; 99:1120-1127. [PMID: 30298804 PMCID: PMC6221205 DOI: 10.4269/ajtmh.18-0303] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antibodies directed against malaria parasites are easy and inexpensive to measure but remain an underused surveillance tool because of a lack of consensus on what to measure and how to interpret results. High-throughput screening of antibodies from well-characterized cohorts offers a means to substantially improve existing assays by rationally choosing the most informative sets of responses and analytical methods. Recent data suggest that high-resolution information on malaria exposure can be obtained from a small number of samples by measuring a handful of properly chosen antibody responses. In this review, we discuss how standardized multi-antibody assays can be developed and efficiently integrated into existing surveillance activities, with potential to greatly augment the breadth and quality of information available to direct and monitor malaria control and elimination efforts.
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Affiliation(s)
- Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, San Francisco, California.,Chan Zuckerberg Biohub, San Francisco, California
| | - David L Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | | | - Ivo Mueller
- Institute Pasteur, Paris, France.,Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Chris J Drakeley
- London School of Hygiene & Tropical Medicine, London, United Kingdom
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18
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Woldearegai TG, Lalremruata A, Nguyen TT, Gmeiner M, Veletzky L, Tazemda-Kuitsouc GB, Matsiegui PB, Mordmüller B, Held J. Characterization of Plasmodium infections among inhabitants of rural areas in Gabon. Sci Rep 2019; 9:9784. [PMID: 31278305 PMCID: PMC6611864 DOI: 10.1038/s41598-019-46194-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/25/2019] [Indexed: 12/18/2022] Open
Abstract
Plasmodium infections in endemic areas are often asymptomatic, can be caused by different species and contribute significantly to transmission. We performed a cross-sectional study in February/March 2016 including 840 individuals ≥ 1 year living in rural Gabon (Ngounié and Moyen-Ogooué). Plasmodium parasitemia was measured by high-sensitive, real-time quantitative PCR. In a randomly chosen subset of P. falciparum infections, gametocyte carriage and prevalence of chloroquine-resistant genotypes were analysed. 618/834 (74%) individuals were positive for Plasmodium 18S-rRNA gene amplification, of these 553 (66.3%) carried P. falciparum, 193 (23%) P. malariae, 74 (8.9%) P. ovale curtisi and 38 (4.6%) P.ovale wallikeri. Non-falciparum infections mostly presented as mixed infections. P. malariae monoinfected individuals were significantly older (median age: 60 years) than coinfected (20 years) or P. falciparum monoinfected individuals (23 years). P. falciparum gametocyte carriage was confirmed in 109/223 (48.9%) individuals, prevalence of chloroquine-resistant genotypes was high (298/336, 89%), including four infections with a new SVMNK genotype. In rural Gabon, Plasmodium infections with all endemic species are frequent, emphasizing that malaria control efforts shall cover asymptomatic infections also including non-falciparum infections when aiming for eradication.
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Affiliation(s)
- Tamirat Gebru Woldearegai
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany.,German Centre for Infection Research, partner site Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Albert Lalremruata
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany.,German Centre for Infection Research, partner site Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - The Trong Nguyen
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany.,German Centre for Infection Research, partner site Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,Vietnamese - German Center of Excellence in Medical Research, Hanoi, Vietnam
| | - Markus Gmeiner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany.,German Centre for Infection Research, partner site Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Luzia Veletzky
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Pierre Blaise Matsiegui
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,Centre de Recherches Médicales de la Ngounié, Fougamou, Gabon
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany.,German Centre for Infection Research, partner site Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Jana Held
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Tübingen, Germany. .,German Centre for Infection Research, partner site Tübingen, Tübingen, Germany. .,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.
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19
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Okuneye K, Eikenberry SE, Gumel AB. Weather-driven malaria transmission model with gonotrophic and sporogonic cycles. JOURNAL OF BIOLOGICAL DYNAMICS 2019; 13:288-324. [PMID: 30691351 DOI: 10.1080/17513758.2019.1570363] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Malaria is mainly a tropical disease and its transmission cycle is heavily influenced by environment: The life-cycles of the Anopheles mosquito vector and Plasmodium parasite are both strongly affected by ambient temperature, while suitable aquatic habitat is necessary for immature mosquito development. Therefore, how global warming may affect malaria burden is an active question, and we develop a new ordinary differential equations-based malaria transmission model that explicitly considers the temperature-dependent Anopheles gonotrophic and Plasmodium sporogonic cycles. Mosquito dynamics are coupled to infection among a human population with symptomatic and asymptomatic disease carriers, as well as temporary immunity. We also explore the effect of incorporating diurnal temperature variations upon transmission. Rigorous analysis of the model show that the non-trivial disease-free equilibrium is locally-asymptotically stable when the associated reproduction number is less than unity (this equilibrium is globally-asymptotically for a special case with no density-dependent larval and disease-induced host mortality). Numerical simulations of the model, for the case where the ambient temperature is held constant, suggest a nonlinear, hyperbolic relationship between the reproduction number and clinical malaria burden. Moreover, malaria burden peaks at 29.5 o C when daily ambient temperature is held constant, but this peak decreases with increasing daily temperature variation, to about 23-25 o C. Malaria burden also varies nonlinearly with temperature, such that small temperature changes influent disease mainly at marginal temperatures, suggesting that in areas where malaria is highly endemic, any response to global warming may be highly nonlinear and most typically minimal, while in areas of more marginal malaria potential (such as the East African highlands), increasing temperatures may translate nearly linearly into increased disease potential. Finally, we observe that while explicitly modelling the stages of the Plasmodium sporogonic cycle is essential, explicitly including the stages of the Anopheles gonotrophic cycle is of minimal importance.
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Affiliation(s)
- Kamaldeen Okuneye
- a School of Mathematical and Statistical Sciences, Arizona State University , Tempe , Arizona 85287 , USA
| | - Steffen E Eikenberry
- a School of Mathematical and Statistical Sciences, Arizona State University , Tempe , Arizona 85287 , USA
| | - Abba B Gumel
- a School of Mathematical and Statistical Sciences, Arizona State University , Tempe , Arizona 85287 , USA
- b Department of Mathematics and Applied Mathematics, University of Pretoria , Pretoria , South Africa
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20
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Frimpong A, Kusi KA, Ofori MF, Ndifon W. Novel Strategies for Malaria Vaccine Design. Front Immunol 2018; 9:2769. [PMID: 30555463 PMCID: PMC6281765 DOI: 10.3389/fimmu.2018.02769] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 11/12/2018] [Indexed: 12/19/2022] Open
Abstract
The quest for a licensed effective vaccine against malaria remains a global priority. Even though classical vaccine design strategies have been successful for some viral and bacterial pathogens, little success has been achieved for Plasmodium falciparum, which causes the deadliest form of malaria due to its diversity and ability to evade host immune responses. Nevertheless, recent advances in vaccinology through high throughput discovery of immune correlates of protection, lymphocyte repertoire sequencing and structural design of immunogens, provide a comprehensive approach to identifying and designing a highly efficacious vaccine for malaria. In this review, we discuss novel vaccine approaches that can be employed in malaria vaccine design.
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Affiliation(s)
- Augustina Frimpong
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.,Immunology Department, College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.,African Institute for Mathematical Sciences, Cape Coast, Ghana
| | - Kwadwo Asamoah Kusi
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.,Immunology Department, College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Michael Fokuo Ofori
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.,Immunology Department, College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Wilfred Ndifon
- African Institute for Mathematical Sciences, Cape Coast, Ghana.,African Institute for Mathematical Sciences, University of Stellenbosch, Cape Town, South Africa
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21
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Abstract
The acquisition of immunity to malaria by an individual depends on their age and the number of infectious mosquito bites they have received.
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Affiliation(s)
- Michael White
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - James Watson
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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22
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Rodriguez-Barraquer I, Arinaitwe E, Jagannathan P, Kamya MR, Rosenthal PJ, Rek J, Dorsey G, Nankabirwa J, Staedke SG, Kilama M, Drakeley C, Ssewanyana I, Smith DL, Greenhouse B. Quantification of anti-parasite and anti-disease immunity to malaria as a function of age and exposure. eLife 2018; 7:35832. [PMID: 30044224 PMCID: PMC6103767 DOI: 10.7554/elife.35832] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 07/15/2018] [Indexed: 01/13/2023] Open
Abstract
Fundamental gaps remain in our understanding of how immunity to malaria develops. We used detailed clinical and entomological data from parallel cohort studies conducted across the malaria transmission spectrum in Uganda to quantify the development of immunity against symptomatic P. falciparum as a function of age and transmission intensity. We focus on: anti-parasite immunity (i.e. ability to control parasite densities) and anti-disease immunity (i.e. ability to tolerate higher parasite densities without fever). Our findings suggest a strong effect of age on both types of immunity, not explained by cumulative-exposure. They also show an independent effect of exposure, where children living in moderate/high transmission settings develop immunity faster as transmission increases. Surprisingly, children in the lowest transmission setting appear to develop immunity more efficiently than those living in moderate transmission settings. Anti-parasite and anti-disease immunity develop in parallel, reducing the probability of experiencing symptomatic malaria upon each subsequent P. falciparum infection.
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Affiliation(s)
- Isabel Rodriguez-Barraquer
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, United States
| | | | | | - Moses R Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Phillip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, United States
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, United States
| | | | - Sarah G Staedke
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Maxwell Kilama
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - David L Smith
- Institute of Health Metrics and Evaluation, University of Washington, Seattle, United States
| | - Bryan Greenhouse
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, United States
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23
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Maziarz M, Nabalende H, Otim I, Legason ID, Kinyera T, Ogwang MD, Talisuna AO, Reynolds SJ, Kerchan P, Bhatia K, Biggar RJ, Goedert JJ, Pfeiffer RM, Mbulaiteye SM. A cross-sectional study of asymptomatic Plasmodium falciparum infection burden and risk factors in general population children in 12 villages in northern Uganda. Malar J 2018; 17:240. [PMID: 29925378 PMCID: PMC6011516 DOI: 10.1186/s12936-018-2379-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/08/2018] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Plasmodium falciparum malaria is an important cause of morbidity in northern Uganda. This study was undertaken to assess village-, household-, and individual-level risk factors of asymptomatic falciparum malaria in children in 12 villages in northern Uganda. METHODS Between 10/2011 and 02/2014, 1006 apparently healthy children under 16 years old were enrolled in 12 villages using a stratified, multi-stage, cluster survey design and assessed for P. falciparum malaria infection using the rapid diagnostic test (RDT) and thick film microscopy (TFM), and structured interviewer-administered questionnaires. Associations between weighted P. falciparum malaria prevalence (pfPR), based on RDT, and covariates were estimated as odds ratios and 95% confidence intervals (ORs, 95% CIs) using logistic models accounting for the survey design. RESULTS Among 942 (93.5%) children successfully tested, pfPR was 52.4% by RDT and 32.7% by TFM. Overall pfPR was lower in villages where indoor residual insecticide spray (IRS) was, versus not, implemented (18.4% versus 75.2%, P < 0.0001). However, pfPR was heterogeneous both within IRS (10.6-34.8%) and non-IRS villages (63.6-86.2%). Elevated pfPR was associated with having a sibling who was RDT positive (OR 5.39, 95% CI 2.94-9.90, P = 0.0006) and reporting a fever at enrollment (aOR 4.80, 95% CI 1.94-11.9, P = 0.0094). Decreased pfPR was associated with living in an IRS village (adjusted OR 0.06, 95% CI 0.04-0.07, P < 0.0001), in a household with one (aOR 0.48, 95% CI 0.30-0.76) or more than one child below 5 years (aOR 0.23, 95% CI 0.12-0.44, Ptrend = 0.014), and reporting keeping a goat inside or near the house (aOR 0.42, 95% CI 0.29-0.62, P = 0.0021). CONCLUSIONS The results show high but heterogeneous pfPR in villages in northern Uganda, confirm significantly decreased pfPR associated with IRS implementation, and suggest significant associations with some household characteristics. Further research is needed to elucidate the factors influencing malaria heterogeneity in villages in Uganda.
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Affiliation(s)
- Marlena Maziarz
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Hadijah Nabalende
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Isaac Otim
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Ismail D Legason
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Tobias Kinyera
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Martin D Ogwang
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Ambrose O Talisuna
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
| | - Steven J Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Patrick Kerchan
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Robert J Biggar
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - James J Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Ruth M Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA.
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Eikenberry SE, Gumel AB. Mathematical modeling of climate change and malaria transmission dynamics: a historical review. J Math Biol 2018; 77:857-933. [PMID: 29691632 DOI: 10.1007/s00285-018-1229-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 03/16/2018] [Indexed: 12/24/2022]
Abstract
Malaria, one of the greatest historical killers of mankind, continues to claim around half a million lives annually, with almost all deaths occurring in children under the age of five living in tropical Africa. The range of this disease is limited by climate to the warmer regions of the globe, and so anthropogenic global warming (and climate change more broadly) now threatens to alter the geographic area for potential malaria transmission, as both the Plasmodium malaria parasite and Anopheles mosquito vector have highly temperature-dependent lifecycles, while the aquatic immature Anopheles habitats are also strongly dependent upon rainfall and local hydrodynamics. A wide variety of process-based (or mechanistic) mathematical models have thus been proposed for the complex, highly nonlinear weather-driven Anopheles lifecycle and malaria transmission dynamics, but have reached somewhat disparate conclusions as to optimum temperatures for transmission, and the possible effect of increasing temperatures upon (potential) malaria distribution, with some projecting a large increase in the area at risk for malaria, but others predicting primarily a shift in the disease's geographic range. More generally, both global and local environmental changes drove the initial emergence of P. falciparum as a major human pathogen in tropical Africa some 10,000 years ago, and the disease has a long and deep history through the present. It is the goal of this paper to review major aspects of malaria biology, methods for formalizing these into mathematical forms, uncertainties and controversies in proper modeling methodology, and to provide a timeline of some major modeling efforts from the classical works of Sir Ronald Ross and George Macdonald through recent climate-focused modeling studies. Finally, we attempt to place such mathematical work within a broader historical context for the "million-murdering Death" of malaria.
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Affiliation(s)
- Steffen E Eikenberry
- Global Security Initiative, Arizona State University, Tempe, AZ, USA. .,School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, USA.
| | - Abba B Gumel
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, USA
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25
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Maziarz M, Kinyera T, Otim I, Kagwa P, Nabalende H, Legason ID, Ogwang MD, Kirimunda S, Emmanuel B, Reynolds SJ, Kerchan P, Joloba MM, Bergen AW, Bhatia K, Talisuna AO, Biggar RJ, Goedert JJ, Pfeiffer RM, Mbulaiteye SM. Age and geographic patterns of Plasmodium falciparum malaria infection in a representative sample of children living in Burkitt lymphoma-endemic areas of northern Uganda. Malar J 2017; 16:124. [PMID: 28320389 PMCID: PMC5360076 DOI: 10.1186/s12936-017-1778-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 03/15/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Falciparum malaria is an important risk factor for African Burkitt lymphoma (BL), but few studies have evaluated malaria patterns in healthy BL-age children in populations where both diseases are endemic. To obtain accurate current data, patterns of asymptomatic malaria were investigated in northern Uganda, where BL is endemic. METHODS Between 2011 and 2015, 1150 apparently healthy children under 15 years old were sampled from 100 villages in northern Uganda using a stratified, multi-stage, cluster survey design. Falciparum malaria prevalence (pfPR) was assessed by questionnaire, rapid diagnostic test (RDT) and thick film microscopy (TFM). Weighted pfPR and unadjusted and adjusted associations of prevalence with covariates were calculated using logistic models and survey methods. RESULTS Based on 1143 children successfully tested, weighted pfPR was 54.8% by RDT and 43.4% by TFM. RDT sensitivity and specificity were 97.5 and 77.8%, respectively, as compared to TFM, because RDT detect malaria antigens, which persist in peripheral blood after clinical malaria, thus results based on RDT are reported. Weighted pfPR increased from 40% in children aged under 2 years to 61.8% in children aged 6-8 years (odds ratio 2.42, 95% confidence interval (CI) 1.26-4.65), then fell slightly to 49% in those aged 12-15 years. Geometric mean parasite density was 1805.5 parasites/µL (95% CI 1344.6-2424.3) among TFM-positive participants, and it was higher in children aged <5 years at 5092.9/µL (95% CI 2892.7-8966.8) and lower in those aged ≥10 years at 983.8/µL (95% CI 472.7-2047.4; P = 0.001). Weighted pfPR was lower in children residing in sub-regions employing indoor residual spraying (IRS) than in those residing in non-IRS sub-regions (32.8 versus 65.7%; OR 0.26, 95% CI 0.14, 0.46). However, pfPR varied both within IRS (3.2-55.3%) and non-IRS sub-regions (29.8-75.8%; Pheterogeneity <0.001). pfPR was inversely correlated with a child's mother's income (P = 0.011) and positively correlated with being enrolled in the wet season (P = 0.076), but sex was irrelevant. CONCLUSIONS The study observed high but geographically and demographically heterogenous patterns of asymptomatic malaria prevalence among children living in northern Uganda. These results provide important baseline data that will enable precise evaluation of associations between malaria and BL.
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Affiliation(s)
- Marlena Maziarz
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
| | - Tobias Kinyera
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- St. Mary’s Hospital, Lacor, Gulu, Uganda
| | - Isaac Otim
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- St. Mary’s Hospital, Lacor, Gulu, Uganda
| | - Paul Kagwa
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- St. Mary’s Hospital, Lacor, Gulu, Uganda
| | - Hadijah Nabalende
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- St. Mary’s Hospital, Lacor, Gulu, Uganda
| | - Ismail D. Legason
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- St. Mary’s Hospital, Lacor, Gulu, Uganda
| | - Martin D. Ogwang
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- St. Mary’s Hospital, Lacor, Gulu, Uganda
| | - Samuel Kirimunda
- Department of Medical Microbiology, Makerere Medical School, Kampala, Uganda
| | - Benjamin Emmanuel
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
- University of Maryland, Baltimore, MD USA
| | - Steven J. Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Patrick Kerchan
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
- Kuluva Hospital, Kuluva, Arua, Uganda
| | - Moses M. Joloba
- Department of Medical Microbiology, Makerere Medical School, Kampala, Uganda
| | - Andrew W. Bergen
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
| | | | - Robert J. Biggar
- Institute of Health and Biotechnical Innovation, Queensland University of Technology, Brisbane, Australia
| | - James J. Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
| | - Ruth M. Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
| | - Sam M. Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
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