Spatial and temporal village-level prevalence of Plasmodium infection and associated risk factors in two districts of Meghalaya, India

• Published in: Malaria Journal
• Main Authors: Anne Kessler, Badondor Shylla, Upasana Shyamsunder Singh, Rilynti Lyngdoh, Bandapkupar Mawkhlieng, Anna Maria van Eijk, Steven A. Sullivan, Aparup Das, Catherine Walton, Mark L. Wilson, Jane M. Carlton, Sandra Albert
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2021
• Subjects: Subpatent Plasmodium infections; Anopheles mosquito abundance; Declining incidence; Malaria elimination; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-021-03600-w; https://doaj.org/article/ddd49053680843d583384826a5cdde1f

Abstract Background Despite declining incidence over the past decade, malaria remains an important health burden in India. This study aimed to assess the village-level temporal patterns of Plasmodium infection in two districts of the north-eastern state of Meghalaya and evaluate risk factors that might explain these patterns. Methods Primary Health Centre passive malaria case data from 2014 to 2018 were analysed to characterize village-specific annual incidence and temporal trends. Active malaria case detection was undertaken in 2018 and 2019 to detect Plasmodium infections using PCR. A questionnaire collected socio-demographic, environmental, and behavioural data, and households were spatially mapped via GPS. Adult mosquitoes were sampled at a subset of subjects' houses, and Anopheles were identified by PCR and sequencing. Risk factors for Plasmodium infection were evaluated using bivariate and multivariate logistic regression analysis, and spatial cluster analysis was undertaken. Results The annual malaria incidence from PHC-based passive surveillance datasets in 2014–2018 was heterogenous but declining across villages in both districts. Active surveillance in 2018 enrolled 1468 individuals from 468 households (West Jaintia Hills) and 1274 individuals from 359 households (West Khasi Hills). Plasmodium falciparum prevalence per 100 people varied from 0 to 4.1% in the nine villages of West Jaintia Hills, and from 0 to 10.6% in the 12 villages of West Khasi Hills. Significant clustering of P. falciparum infections [observed = 11, expected = 2.15, Relative Risk (RR) = 12.65; p < 0.001] was observed in West Khasi Hills. A total of 13 Anopheles species were found at 53 houses in five villages, with Anopheles jeyporiensis being the most abundant. Risk of infection increased with presence of mosquitoes and electricity in the households [Odds Ratio (OR) = 1.19 and 1.11], respectively. Households with reported animals had reduced infection risk (OR = 0.91). Conclusion Malaria incidence during 2014–2018 declined in ...