Socioeconomic and Household Environmental Determinants of Diarrhoeal Disease in Under-Five Children: A Comprehensive Analysis in Karnataka, India

Background: Diarrhoeal disease remains a leading cause of under-five morbidity in India, with substantial sub-state heterogeneity. Karnataka has shown progress overall, yet district-level disparities persist. This study assessed the prevalence and determinants of diarrhoeal morbidity among under-five children in Karnataka using data from the National Family Health Survey-5 (NFHS-5). Methods: A cross-sectional analysis was conducted using NFHS-5 data (2019-2021). A total of 8,140 under-five children from Karnataka were included after applying exclusion criteria. Socio-demographic, maternal, and household environmental variables were examined. Associations were assessed using chi-square tests and bivariable logistic regression, followed by multivariable logistic regression to identify independent predictors, accounting for potential confounders. Results: The overall prevalence of diarrhoea among under-five children in Karnataka was 5.3%, with notable variation across districts. Higher prevalence was observed among children aged 12-23 months, male children, those born to younger mothers (<25 years), children from Scheduled Caste households, and those from poorer wealth quintiles. In the adjusted analysis, maternal age <25 years (AOR = 3.47; 95% CI: 1.31-9.14) and use of unsafe cooking fuel (AOR = 3.89; 95% CI: 1.39-10.91) emerged as significant independent predictors of diarrhoeal morbidity. Unimproved drinking water showed a borderline association. Several factors, including child sex, breastfeeding status, sanitation type, and stool disposal practices, were not independently associated after adjustment. Conclusion: Childhood diarrhoea in Karnataka is influenced by a combination of maternal and household environmental factors. Interventions targeting young mothers and reducing household exposure to unsafe cooking fuels may help further reduce the burden of diarrhoeal morbidity among under-five children.