Asian Journal of Environment & Ecology

Water-borne diseases remain an enduring and significant public health challenge in India, responsible for considerable morbidity and mortality across all age groups, with children under five bearing the greatest burden. Against this backdrop, the accelerating effects of anthropogenic climate change are altering the hydrological, ecological, and social conditions that govern pathogen transmission. This narrative review synthesises peer-reviewed epidemiological, microbiological, and environmental health literature published between 2000 and 2025 to evaluate how observed and projected climate trajectories—including rising temperatures, intensifying monsoon precipitation, more frequent and severe flooding, and prolonged drought—are influencing the prevalence, distribution, and seasonality of major water-borne diseases in India. A narrative review methodology was adopted to synthesise multidisciplinary and heterogeneous literature on climate change and water-borne diseases in India using evidence retrieved from databases including Web of Science, Scopus, PubMed, Google Scholar, IndMED, WHO Global Index Medicus, Global Environmental Health, CINAHL, and FAO AGRIS, along with authoritative institutional sources. The principal diseases examined are cholera, typhoid and enteric fevers, hepatitis A and E, leptospirosis, and diarrhoeal illness of diverse aetiology. The review identifies several well-supported mechanisms connecting climate variables to disease risk, including temperature-driven amplification of pathogen survival and replication, flood-mediated contamination of drinking-water sources, and drought-induced deterioration of water quality and supply. Regional analyses reveal that the Ganges–Brahmaputra basin and coastal eastern India face the most acute and best-documented risks, while southern India and the semi-arid west present distinct but equally serious vulnerabilities. The compounding role of inadequate water, sanitation, and hygiene (WASH) infrastructure, persistent poverty, and socio-economic inequality is emphasised throughout. Evidence for adaptation strategies—including climate-resilient WASH design, point-of-use treatment, targeted vaccination, improved disease surveillance, and climate-informed early warning systems—is reviewed and found to be promising but underimplemented. Significant research gaps remain, particularly regarding causal attribution, prospective cohort data, and disease modelling tailored to Indian conditions. The findings underscore the urgency of integrating climate considerations into India's public health planning and infrastructure investment.