Abstract
Malaria in Bhutan has fallen significantly over the last decade. As Bhutan attempts to eliminate malaria in 2022, this study aimed to characterize the space–time clustering of malaria from 2010 to 2019. Malaria data were obtained from the Bhutan Vector-Borne Disease Control Program data repository. Spatial and space–time cluster analyses of Plasmodium falciparum and Plasmodium vivax cases were conducted at the sub-district level from 2010 to 2019 using Kulldorff’s space–time scan statistic. A total of 768 confirmed malaria cases, including 454 (59%) P. vivax cases, were reported in Bhutan during the study period. Significant temporal clusters of cases caused by both species were identified between April and September. The most likely spatial clusters were detected in the central part of Bhutan throughout the study period. The most likely space–time cluster was in Sarpang District and neighboring districts between January 2010 to June 2012 for cases of infection with both species. The most likely cluster for P. falciparum infection had a radius of 50.4 km and included 26 sub-districts with a relative risk (RR) of 32.7. The most likely cluster for P. vivax infection had a radius of 33.6 km with 11 sub-districts and RR of 27.7. Three secondary space–time clusters were detected in other parts of Bhutan. Spatial and space–time cluster analysis identified high-risk areas and periods for both P. vivax and P. falciparum malaria. Both malaria types showed significant spatial and spatiotemporal variations. Operational research to understand the drivers of residual transmission in hotspot sub-districts will help to overcome the final challenges of malaria elimination in Bhutan.
Highlights
314 (41%) patients infected with P. falciparum and 454 (59%) with P. vivax
The yearly annual parasite incidence (API) of sub-districts is shown in Supplementary Figures S1 and S2
Malaria clusters of57.15 both species observed in the central parts of Bhutan along the international border throughout the study period
Summary
Introduction conditions of the Creative CommonsHistorically, malaria in Bhutan has been reported from seven out of twenty districts: Chukha, Dagana, Pemagatshel, Samdrup Jongkhar, Samtse, Sarpang and Zhemgang [1].These districts lie in the southern foothills of the Himalayas bordering the Indian states of Attribution (CC BY) license (https://creativecommons.org/licenses/by/ 4.0/).Int. J. Environ. Res. Public Health 2021, 18, 5553. https://doi.org/10.3390/ijerph18115553 https://www.mdpi.com/journal/ijerph
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have