Climatic and socio-environmental drivers of Cholera epidemics: Cascading effects and spatial variability in developing regions

Abstract

Cholera remains a persistent public health challenge in developing countries, driven by poor Water, Sanitation and Hygiene (WASH) infrastructure and weak healthcare systems. Growing evidence highlights the significant role of climatic factors such as temperature, rainfall variability (floods and droughts), Sea Surface Temperatures (SSTs), tropical cyclones and large-scale climate drivers like the El Niño-Southern Oscillation (ENSO) on cholera dynamics. High temperatures, moderate salinity, and nutrient enrichment promote Vibrio cholerae proliferation, while extreme rainfall and flooding contaminate water sources, exacerbating transmission. Conversely, drought intensifies exposure to unsafe water, increasing infection risk. Vibrio cholerae thrive in moderate salinity, experiences optimal growth in temperatures between (25–30) °C and reduced survival beyond 30°C and extreme salinity. Despite this growing body of knowledge, current evidence is fragmented across regions and disciplines, with few reviews systematically integrating climatic and socio-environmental determinants of cholera. Existing studies often emphasize individual climatic drivers without addressing their spatial variability, compounding and cascading interactions with non-climatic factors. The narrative review addresses these gaps by synthesizing peer reviewed literature (2000–2024) from Google Scholar and PubMed to examine the multi-scalar influences of climate on cholera in developing regions. Findings reveal that cholera is not driven by the same climatic mechanism everywhere. It is a spatially heterogeneous climate sensitive disease, with spatial heterogeneity extending to seasonality, lag times not just drivers both regions. Temperature dominates mostly inland systems with delayed risk and rainfall drives rapid outbreaks in flood prone settings. Compound climate extremes interacting with socio-economic vulnerability amplify non-linear, region-specific transmission pathways. Most African coastal outbreaks are imported rather than locally amplified distinguishing Africa from South Asia. By consolidating and comparing evidence across regions, this review provides a holistic assessment of the climate-cholera nexus, highlighting pathways to strengthen early warning, preparedness, and resilience strategies in vulnerable developing regions.