Geospatial analysis of diarrheal disease burden and associated health determinants among under-five children in Karnataka using NFHS data

Diarrhoeal disease remains a major contributor to under-five morbidity and mortality in India, despite significant public health investments. This study investigates the spatial and temporal distribution of diarrhoeal disease among children under five across Karnataka, using data from two rounds of the National Family Health Survey (NFHS-4: 2015-16 and NFHS-5: 2019-21). District-level prevalence data were extracted, georeferenced, and analyzed using Local Indicators of Spatial Association (LISA) and Moran's I statistics to identify clustering patterns and spatial dependencies. The analysis revealed considerable spatial heterogeneity, with emerging hotspots in northern districts such as Bidar and Kalaburagi and declining trends in southern districts like Mysuru and Chikkamagaluru. Univariate LISA identified high-high clusters in NFHS-4, which weakened in NFHS-5, indicating a shift in spatial concentration. Bivariate spatial analysis demonstrated evolving associations between diarrhoeal prevalence and determinants such as sanitation, undernutrition, and dietary adequacy. Notably, consistent spatial co-clustering was observed between diarrhoea and underweight prevalence. These findings provide critical insights into the evolving spatial dynamics of childhood diarrhoeal disease and highlight the importance of localized surveillance to identify high-burden districts and prioritize context-specific public health interventions.