Identification of micro-level malaria hotspots and its implications for achieving malaria elimination target in a...

India has made remarkable progress in lowering the incidence of malaria cases. Epidemiological investigation of performance matrices and spatiotemporal characteristics, particularly at the district and sub-district levels is crucial for proper allocation of resources. This study aims to identify hotspot in context of malaria endemic Sonbhadra district to set an exemplar to guide targeted interventions.

Malaria surveillance data spanning 2017 to 2024, were analyzed to estimate future case scenario. Kulldorf scanning with discrete Poission probability model was used for detection of high-risk malaria clusters. Mean Annual Rate of Change (AROC) and Maximum AROC were calculated to project the year of zero malaria case status.

A total of 18,217 malaria cases were reported during 2017 to 2024 from this district. A decrease was observed in test positivity rates (TPR) with 95% reduction in cases during the study period. Annual parasite incidences (API) decreased from 2.7 in 2017 to 0.1 in 2024 and annual falciparum incidence (AFI) showed a late-period fluctuation, rising to 0.09 in 2024 after a near total suppression in 2022 and 2023. The most significant malaria hotspot was present at western part of this district at Chopan block. Presence of high-risk clusters of both Plasmodium falciparum and P. vivax at sub-district level was alarming for the maintenance of sustainable malaria reduction goals.

This study provides an insight to identify local malaria foci at micro-level for evidence-based targeting of resources using spatiotemporal epidemiology, and facilitating multisectoral coordination involving community to accelerate micro-level elimination targets.