Topographic analysis to explain heterogenous malaria prevalence in the highlands of Uganda

Keywords: health geography, medical geography, malaria, topography, Uganda, Africa, mosquito habitats, habitat suitability, remote sensing
Session Type: Virtual Poster Abstract
Day: Friday
Session Start / End Time: 2/25/2022 05:20 PM (Eastern Time (US & Canada)) - 2/25/2022 06:40 PM (Eastern Time (US & Canada))
Room: Virtual 21

Abstract

Malaria transmission intensity in the highlands of western Uganda is characterized by spatial heterogeneity, which is likely attributable to the region’s rugged and varied topography. Therefore, we hypothesize that topographic analysis may serve as a practical and effective tool for identifying “hotspots” and areas suitable for mosquito breeding sites. To test this hypothesis, we leveraged the results of a cross-sectional malaria survey in three non-contiguous villages in the Bugoye sub-county of western Uganda conducted in November 2020. This survey revealed malaria prevalence rates among children ages 0 to 12 years in Bunyangoni, Rwaking 1A, and Kisanzi of 4.52, 14.29, and 20.22% respectively. We then used a digital elevation model (DEM) and remotely sensed imagery to calculate the topographic wetness index (TWI), normalized difference vegetation index (NDVI), and normalized difference water index (NDWI) for the area. From this, we modeled the parasite prevalence – the primary outcome of interest – with the TWI, NDVI, and NDWI as explanatory variables. Preliminary results show that these measures were weak and not statistically significant. Potential limitations include survey incompleteness, small study area size, and possible influence of other confounding variables. However, this work provides an early proof-of-concept of how remotely sensed data could be used in remote settings where conventional fieldwork is logistically challenging. We are currently exploring a habitat suitability model that could facilitate targeted vector control interventions.