Water sustains life — and, when unsafe, spreads it. This page explains what water-associated diseases are, profiles the major ones, and tracks how they affect people today, from global trends down to India's rivers, wells and monsoons, and how a changing climate is making the problem worse.
Understand the categories Jump to India data CLEANSE Dashboard ↗Public health agencies, including WHO, group illnesses linked to water into four categories based on how water plays a role in transmission — not just diseases from drinking dirty water, but also those linked to too little water, water as a habitat, and water-breeding insects.
Caused by ingesting water contaminated with pathogens from human or animal faeces — drunk, or used to cook or wash food. Example: cholera, typhoid, hepatitis A.
Caused by a shortage of clean water for washing and hygiene, not contamination itself. Example: trachoma, scabies, skin and eye infections.
Caused by parasites that spend part of their life cycle in water, often inside a snail or other aquatic host, then infect people in the water. Example: schistosomiasis (bilharzia), guinea worm.
Spread by insects that breed in or near water, though the illness itself doesn't come from drinking or touching it. Example: malaria and dengue (mosquitoes), river blindness.
Ten conditions that account for most of the global and Indian burden linked to unsafe water, sanitation and hygiene (WASH).
Unsafe water, sanitation and hygiene remain among the largest preventable causes of illness and death globally, hitting children and low-income countries hardest.
Bars are scaled independently to the largest value in this chart for visual comparison, not to one shared axis.
India has made rapid progress on piped water access, yet the disease burden from unsafe water and geogenic (naturally occurring) contaminants remains substantial.
Cases reported to India's health surveillance system, 2005–2022 (source: government data compiled by Factly/Dataful). Acute Diarrhoeal Disease accounts for nearly 9 of every 10 cases, but Viral Hepatitis has the highest death toll relative to its case count (9,980 deaths from just 0.21 crore cases).
Rising temperatures, erratic rainfall, floods and droughts are not creating new diseases — they are amplifying the reach and duration of the ones described above.
3.6 billion people already live in areas highly susceptible to climate change. Extreme weather events increase death and illness directly, but also indirectly by contaminating water sources, disrupting sanitation systems, and lengthening the breeding season for disease-carrying mosquitoes. In the most climate-vulnerable regions, the death rate from extreme weather over the past decade has been roughly 15 times higher than in less vulnerable regions.
Flooding is a especially direct trigger: it overwhelms sewage and drainage systems, mixes waste into drinking-water sources, and creates stagnant pools that breed mosquitoes — a pattern seen repeatedly after floods across South and Southeast Asia.
Extreme monsoon rainfall caused unprecedented floods in Kerala, followed by a spike in leptospirosis (a water-related bacterial disease spread via flood water contaminated with animal urine).
Prolonged, then heavy, rainfall triggered large-scale flooding in Assam, affecting over 5.5 million people and raising the risk of water-, vector- and food-borne disease outbreaks.
Multi-day extreme precipitation events caused major flooding across India during the summer monsoon, consistent with a broader trend of intensifying rainfall.
Nearly 70% of disease outbreaks reported by India's Ministry of Health & Family Welfare are waterborne, and intensifying rainfall combined with rising temperatures is extending the transmission season for these diseases.
Most water-associated disease is preventable with a small set of consistent practices, at both household and community level.
Safe water, sanitation and hygiene (WASH) together break the transmission cycle for most of the diseases on this page.
Share this page, check your own household's water source, and support local sanitation and water-access efforts. Future modules on this site will add live dashboards tracking water access and quality data.