Fine-scale variation in malaria prevalence across ecological regions in Madagascar: a cross-sectional study

BMC Public Health

James Hazen¹  C. Jessica E. Metcalf²  Marcia C. Castro³  Daniel L. Hartl⁴  Benjamin L. Rice⁵  Evelin Jean Gasta Anjaranirina⁶  Miadana Arisoa Vonona⁶  Anjaharinony Andry Ny Aina Rakotomalala⁷  Hervet J. Randriamady⁸  Christopher D. Golden⁸ 

[1] Catholic Relief Services (CRS) Madagascar, Antananarivo, Madagascar;Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA;Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, MA, USA;Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA;Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA;Madagascar Health and Environmental Research (MAHERY), Maroantsetra, Madagascar;Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA;Madagascar Health and Environmental Research (MAHERY), Maroantsetra, Madagascar;Madagascar Health and Environmental Research (MAHERY), Maroantsetra, Madagascar;Department of Entomology, University of Antananarivo, Antananarivo, Madagascar;Madagascar Health and Environmental Research (MAHERY), Maroantsetra, Madagascar;Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA;

关键词: Madagascar;    Malaria;    Ecology;    Spatial variation;    Community health;   

DOI  :  10.1186/s12889-021-11090-3

来源: Springer

【 摘 要 】

BackgroundLarge-scale variation in ecological parameters across Madagascar is hypothesized to drive varying spatial patterns of malaria infection. However, to date, few studies of parasite prevalence with resolution at finer, sub-regional spatial scales are available. As a result, there is a poor understanding of how Madagascar’s diverse local ecologies link with variation in the distribution of infections at the community and household level. Efforts to preserve Madagascar’s ecological diversity often focus on improving livelihoods in rural communities near remaining forested areas but are limited by a lack of data on their infectious disease burden.MethodsTo investigate spatial variation in malaria prevalence at the sub-regional scale in Madagascar, we sampled 1476 households (7117 total individuals, all ages) from 31 rural communities divided among five ecologically distinct regions. The sampled regions range from tropical rainforest to semi-arid, spiny forest and include communities near protected areas including the Masoala, Makira, and Mikea forests. Malaria prevalence was estimated by rapid diagnostic test (RDT) cross-sectional surveys performed during malaria transmission seasons over 2013–2017.ResultsIndicative of localized hotspots, malaria prevalence varied more than 10-fold between nearby (< 50 km) communities in some cases. Prevalence was highest on average in the west coast region (Morombe district, average community prevalence 29.4%), situated near protected dry deciduous forest habitat. At the household level, communities in southeast Madagascar (Mananjary district) were observed with over 50% of households containing multiple infected individuals at the time of sampling. From simulations accounting for variation in household size and prevalence at the community level, we observed a significant excess of households with multiple infections in rural communities in southwest and southeast Madagascar, suggesting variation in risk within communities.ConclusionsOur data suggest that the malaria infection burden experienced by rural communities in Madagascar varies greatly at smaller spatial scales (i.e., at the community and household level) and that the southeast and west coast ecological regions warrant further attention from disease control efforts. Conservation and development efforts in these regions may benefit from consideration of the high, and variable, malaria prevalences among communities in these areas.

【 授权许可】

CC BY