Geospatial Analysis of Malaria Burden in Kagera Region, Northwestern Tanzania Using Health Facility and Community Survey Data.

Abstract

Background: Malaria transmission in Tanzania has declined significantly over the last 2 decades due to scaled-up control interventions. However, recent confirmation of artemisinin partial resistance (ART-R) in Kagera region in northwest Tanzania threatens the ongoing efforts to eliminate malaria in the country. This study was conducted according to the World Health Organization recommendation to generate evidence of malaria burden in areas with confirmed ART-R as the first step before developing a response strategy to the resistance.

Methods: We assessed the local burden of malaria in Kagera region by geospatial analysis, using data collected retrospectively from health facilities and community surveys from 2015 to 2023 to identify malaria hot spots.

Results: From 2017 to 2023, a total of 8 124 363 suspected malaria cases were reported by health facilities, and 2 983 717 (36.7% [95% range across wards, 22.7%-50.7%]) tested positive by rapid diagnostic tests. Test positivity rates were similar among patients aged <5 years (33.1% [95% range, 19.7%-46.5%]) and those aged ≥5 years (33.7% [21.0%-46.5%]). The malaria prevalence was 10.0% (95% range across wards, 5.1%-14.9% [n = 84 999 of 853 761]) in pregnant women and 26.1% (11.7%-40.6% [n = 3409 of 13 065]) in schoolchildren. Despite high temporal variations, we identified hot spots and cold spots, including persistently high burden in 69 of 192 wards (35.9%).

Conclusions: The malaria burden in Kagera exhibited high temporal and spatial heterogeneity, with schoolchildren showing the highest prevalence. This demographic pattern underlines the need for targeted interventions and provides evidence for developing an ART-R response for the region.