Spatial Epidemiology of Cholera Outbreaks in Kano State Using GIS

Cholera remains a recurrent epidemic disease in North West Nigeria, concentrated in densely populated low-income urban communities with inadequate water and sanitation infrastructure. This study applies spatial epidemiology methods within a GIS framework to analyse cholera outbreak patterns in Kano State for the period 2019 to 2023. Cholera case data from the Kano State Ministry of Health, including community of residence and onset date for 7,840 confirmed cases, are geo-referenced to ward boundaries. Spatial scan statistics using SaTScan software identify significant high-risk clusters. Bayesian disease mapping produces smoothed risk maps controlling for population size variation. Environmental risk factors derived from satellite imagery including proximity to open drainage channels, surface water extent, and settlement density are integrated into a logistic regression risk model. Results identify Gwale, Dala, and Fagge as consistent cluster wards across all five study years. Proximity to open drains and inadequate piped water access explain 71 percent of the spatial variation in case rates. Keywords: cholera, spatial epidemiology, GIS, Kano State, disease mapping