Diarrhoea in children under 5 years in two informal settlements in Accra, Ghana: The impact of antecedent rainfall and flooding

Diarrhoea is a common and critical public health problem among children under five years of age in Africa's urban informal communities, resulting in high mortality. Poor sanitation and high microbial concentrations in surface waters, along with environmental factors such as rainfall and temperature, can increase diarrhoeal incidence, particularly during floods. However, information on the dynamic effects of these covariates is limited. This research in two informal settlements in Accra, Ghana - Gbegbeyise (GB) and Madina Zongo (MZ) - examined the relationship between diarrhoea cases in children under five and environmental factors. Bi-weekly data were collected from selected households over two years. Only the pre-intervention 40 visits were analysed, which were known to be relatively temporally stationary, using two Poisson regression models. The first model identified a significant relationship between diarrhoea cases and antecedent (up to 1-week) rainfall (significant in both settlements) and temperature (significant only in GB). The second model examined the association between the total count of diarrhoea cases and the spatial proximity of households to flood-prone areas and elevation, revealing that cases are expected to increase with proximity to flood areas (p < 0.001). Thus, the analysis established the importance of antecedent rainfall in increasing disease risk and identifies a potential pathway (flood water), linking disease risk to that rainfall. These findings highlight the potential role of rainfall and water in diarrhoeal disease transmission and underscore the importance of integrating climate-sensitive health interventions in informal settlements to mitigate the impact of diarrhoea in vulnerable communities exposed to flooding and poor sanitation.