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Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands

BACKGROUND: Assessment of malaria endemicity at different altitudes and transmission intensities, in the era of dwindling vector densities in the highlands, will provide valuable information for malaria control and surveillance. Measurement of serum anti-malarial antibodies is a useful marker of mal...

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Autores principales: Badu, Kingsley, Afrane, Yaw Asare, Larbi, John, Stewart, Virginia Ann, Waitumbi, John, Angov, Evelina, Ong'echa, John M, Perkins, Douglas J, Zhou, Guofa, Githeko, Andrew, Yan, Guiyun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306741/
https://www.ncbi.nlm.nih.gov/pubmed/22380785
http://dx.doi.org/10.1186/1471-2334-12-50
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author Badu, Kingsley
Afrane, Yaw Asare
Larbi, John
Stewart, Virginia Ann
Waitumbi, John
Angov, Evelina
Ong'echa, John M
Perkins, Douglas J
Zhou, Guofa
Githeko, Andrew
Yan, Guiyun
author_facet Badu, Kingsley
Afrane, Yaw Asare
Larbi, John
Stewart, Virginia Ann
Waitumbi, John
Angov, Evelina
Ong'echa, John M
Perkins, Douglas J
Zhou, Guofa
Githeko, Andrew
Yan, Guiyun
author_sort Badu, Kingsley
collection PubMed
description BACKGROUND: Assessment of malaria endemicity at different altitudes and transmission intensities, in the era of dwindling vector densities in the highlands, will provide valuable information for malaria control and surveillance. Measurement of serum anti-malarial antibodies is a useful marker of malaria exposure that indicates long-term transmission potential. We studied the serologic evidence of malaria endemicity at two highland sites along a transmission intensity cline. An improved understanding of the micro-geographic variation in malaria exposure in the highland ecosystems will be relevant in planning effective malaria control. METHODS: Total IgG levels to Plasmodium falciparum MSP-1(19 )were measured in an age-stratified cohort (< 5, 5-14 and ≥ 15 years) in 795 participants from an uphill and valley bottom residents during low and high malaria transmission seasons. Antibody prevalence and level was compared between different localities. Regression analysis was performed to examine the association between antibody prevalence and parasite prevalence. Age-specific MSP-1(19 )seroprevalence data was fitted to a simple reversible catalytic model to investigate the relationship between parasite exposure and age. RESULTS: Higher MSP-1(19 )seroprevalence and density were observed in the valley residents than in the uphill dwellers. Adults (> 15 years) recorded high and stable immune response in spite of changing seasons. Lower responses were observed in children (≤ 15 years), which, fluctuated with changing seasons particularly in the valley residents. In the uphill population, annual seroconversion rate (SCR) was 8.3% and reversion rate was 3.0%, with seroprevalence reaching a plateau of 73.3% by age of 20. Contrary, in the valley bottom population, the annual SCR was 35.8% and the annual seroreversion rate was 3.5%, and seroprevalence in the population had reached 91.2% by age 10. CONCLUSION: The study reveals the micro-geographic variation in malaria endemicity in the highland eco-system; this validates the usefulness of sero-epidemiological tools in assessing malaria endemicity in the era of decreasing sensitivity of conventional tools.
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spelling pubmed-33067412012-03-19 Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands Badu, Kingsley Afrane, Yaw Asare Larbi, John Stewart, Virginia Ann Waitumbi, John Angov, Evelina Ong'echa, John M Perkins, Douglas J Zhou, Guofa Githeko, Andrew Yan, Guiyun BMC Infect Dis Research Article BACKGROUND: Assessment of malaria endemicity at different altitudes and transmission intensities, in the era of dwindling vector densities in the highlands, will provide valuable information for malaria control and surveillance. Measurement of serum anti-malarial antibodies is a useful marker of malaria exposure that indicates long-term transmission potential. We studied the serologic evidence of malaria endemicity at two highland sites along a transmission intensity cline. An improved understanding of the micro-geographic variation in malaria exposure in the highland ecosystems will be relevant in planning effective malaria control. METHODS: Total IgG levels to Plasmodium falciparum MSP-1(19 )were measured in an age-stratified cohort (< 5, 5-14 and ≥ 15 years) in 795 participants from an uphill and valley bottom residents during low and high malaria transmission seasons. Antibody prevalence and level was compared between different localities. Regression analysis was performed to examine the association between antibody prevalence and parasite prevalence. Age-specific MSP-1(19 )seroprevalence data was fitted to a simple reversible catalytic model to investigate the relationship between parasite exposure and age. RESULTS: Higher MSP-1(19 )seroprevalence and density were observed in the valley residents than in the uphill dwellers. Adults (> 15 years) recorded high and stable immune response in spite of changing seasons. Lower responses were observed in children (≤ 15 years), which, fluctuated with changing seasons particularly in the valley residents. In the uphill population, annual seroconversion rate (SCR) was 8.3% and reversion rate was 3.0%, with seroprevalence reaching a plateau of 73.3% by age of 20. Contrary, in the valley bottom population, the annual SCR was 35.8% and the annual seroreversion rate was 3.5%, and seroprevalence in the population had reached 91.2% by age 10. CONCLUSION: The study reveals the micro-geographic variation in malaria endemicity in the highland eco-system; this validates the usefulness of sero-epidemiological tools in assessing malaria endemicity in the era of decreasing sensitivity of conventional tools. BioMed Central 2012-03-01 /pmc/articles/PMC3306741/ /pubmed/22380785 http://dx.doi.org/10.1186/1471-2334-12-50 Text en Copyright ©2012 Badu et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Badu, Kingsley
Afrane, Yaw Asare
Larbi, John
Stewart, Virginia Ann
Waitumbi, John
Angov, Evelina
Ong'echa, John M
Perkins, Douglas J
Zhou, Guofa
Githeko, Andrew
Yan, Guiyun
Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands
title Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands
title_full Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands
title_fullStr Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands
title_full_unstemmed Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands
title_short Marked variation in MSP-1(19 )antibody responses to malaria in western Kenyan highlands
title_sort marked variation in msp-1(19 )antibody responses to malaria in western kenyan highlands
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306741/
https://www.ncbi.nlm.nih.gov/pubmed/22380785
http://dx.doi.org/10.1186/1471-2334-12-50
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