Waterborne disease statistics span broad WASH-related health effects, modeled national burdens and reported outbreaks. The figures below distinguish global estimates from U.S. surveillance, identify measurement periods, and retain each source’s limits.
Key Waterborne Disease Statistics
The most broadly useful figures include:
- In 2019, 1.4 million global deaths were estimated preventable with adequate water supply, sanitation and hygiene.
- In 2019, more than 1 million of the global WASH-related preventable deaths were from diarrhoeal disease.
- In 2019, 7.6% of deaths among children younger than 5 globally were attributed to inadequate WASH.
- Each year, nearly 1.7 billion cases of childhood diarrhoeal disease occur globally.
- Each year, around 443,832 children younger than 5 die from diarrhoea globally.
- Each year, 50,851 children aged 5–9 die from diarrhoea globally.
- In the WHO fact-sheet context, about 780 million people globally lacked improved drinking-water access.
- In the WHO fact-sheet context, about 2.5 billion people globally lacked improved sanitation.
- In 2014, 17 waterborne pathogens caused an estimated 7.15 million illnesses in the United States.
- In 2014, U.S. waterborne disease was estimated to include 601,000 emergency-department visits.
- In 2014, U.S. waterborne disease was estimated to include 118,000 hospitalizations.
- In 2014, U.S. waterborne disease was estimated to cause 6,630 deaths.
- In 2014, direct U.S. healthcare costs for waterborne hospitalizations and emergency visits were estimated at $3.33 billion.
- In 2015, 23 drinking-water-associated outbreaks produced 429 reported U.S. cases.
- In 2015, recreational water was associated with 47 of 82 reported U.S. waterborne outbreaks.
- In 2015, 42 of 82 reported U.S. waterborne outbreaks occurred during June–August.
- In 2013–2014, 42 U.S. drinking-water-associated outbreaks caused at least 1,006 illnesses.
Contents
- Key Waterborne Disease Statistics
- Global Waterborne Disease and WASH Statistics
- U.S. Waterborne Disease Burden, Visits and Costs
- Waterborne Disease Hospitalizations and Deaths by Pathogen
- Drinking-Water Outbreak Statistics and Outcomes
- Recreational-Water Disease Statistics and Settings
- Seasonality, Exposure Routes and Surveillance Limits
Global Waterborne Disease and WASH Statistics
The World Health Organization’s WASH estimates cover disease pathways associated with inadequate water, sanitation and hygiene. They are broader than a count of infections transmitted only through drinking water.
- In 2019, inadequate WASH was estimated to account for 1.4 million preventable deaths globally.
- More than 1 million of those 1.4 million deaths were from diarrhoeal disease.
- Inadequate WASH accounted for 7.6% of all deaths among children younger than 5 globally in 2019.
WHO, “Estimating WASH-related burden of disease” identifies these as WASH-attributable estimates, not direct counts of waterborne infections.
The WHO’s diarrhoeal-disease fact sheet provides additional population-level indicators. These measures help show scale, but not every diarrhoeal case is proven to have been waterborne.
| Global indicator | Figure | Period or population |
|---|---|---|
| Childhood diarrhoeal disease cases | Nearly 1.7 billion | Each year, global children |
| Diarrhoeal deaths | 443,832 | Each year, children under 5 globally |
| Diarrhoeal deaths | 50,851 | Each year, children aged 5–9 globally |
| Average episodes | 3 per child | Each year, children under 3 in low-income countries |
The same WHO fact-sheet context reports about 780 million people without improved drinking-water access and about 2.5 billion without improved sanitation. These are historical “improved” access measures and are not identical to current safely managed service definitions.
WHO, “Diarrhoeal disease” also notes that children under 3 in low-income countries experience an average of three diarrhoeal episodes per year. That is a population average, not a description of every child or proof of water transmission for each episode.
U.S. Waterborne Disease Burden, Visits and Costs
The CDC modeled the U.S. burden for 2014 across 17 waterborne pathogens and multiple exposure routes, including drinking water and recreational water. The results are estimates rather than a complete administrative count.
| Estimated 2014 U.S. outcome | Total |
|---|---|
| Illnesses | 7.15 million |
| Emergency-department visits | 601,000 |
| Hospitalizations | 118,000 |
| Deaths | 6,630 |
| Direct healthcare costs for hospitalizations and emergency visits | $3.33 billion |
CDC, “Estimate of Waterborne Disease Burden in the United States” reports the direct healthcare-cost estimate as $3.33 billion; the source’s stated dollar basis is retained here without an inferred inflation adjustment. The estimate excludes broader productivity and social costs.
The modeled 2014 deaths included approximately 3,300 linked to drinking-water exposure and approximately 1,290 linked to recreational-water exposure. Those are exposure-route attributions within the national model, not separate surveillance counts.
Emergency-department estimates show how a common water-associated condition can dominate visit totals. Otitis externa, or swimmer’s ear, accounted for an estimated 567,000 waterborne emergency-department visits, representing 94% of the listed CDC-table visits.
Other estimated 2014 U.S. waterborne emergency-department visits included 26,300 for norovirus, 5,080 for nontuberculous mycobacterial infection, 667 for Legionnaires’ disease, and 567 for giardiasis. These are modeled water-attributable estimates, not counts of every national case of each condition.
Waterborne Disease Hospitalizations and Deaths by Pathogen
The CDC’s 2014 modeled pathogen results show that mortality was concentrated in several serious conditions. The figures below are estimates, and the stated credible intervals matter because uncertainty varies substantially by pathogen.
| Condition | Estimated waterborne U.S. deaths, 2014 | 95% credible interval where supplied |
|---|---|---|
| Nontuberculous mycobacterial infection | 3,800 | 1,950–5,620 |
| Legionnaires’ disease | 995 | 655–1,310 |
| Pseudomonas pneumonia | 730 | 185–1,460 |
| Pseudomonas septicemia | 695 | 89–1,740 |
| Otitis externa | 219 | 107–367 |
Nontuberculous mycobacterial infection accounted for 57% of deaths in the CDC’s listed pathogen table, while Legionnaires’ disease accounted for 15%. These percentages are shares of the listed modeled deaths, not mortality rates among infected people.
The wide intervals for Pseudomonas pneumonia and septicemia illustrate why point estimates should not be read as exact counts. CDC, “Estimate of Waterborne Disease Burden in the United States” presents the pathogen estimates and their uncertainty.
Drinking-Water Outbreak Statistics and Outcomes
CDC outbreak surveillance records linked cases and implicated water exposures, so it measures reported outbreaks rather than population incidence. Reporting is voluntary and likely undercounts actual occurrence.
In 2015, CDC recorded 23 drinking-water-associated outbreaks in the United States. These outbreaks produced 429 reported cases, 124 hospitalizations and 25 deaths.
| 2015 reported U.S. waterborne outbreak measure | Drinking-water share |
|---|---|
| Outbreaks | 23 of 82, or 28% |
| Cases | 34% of reported outbreak-associated cases |
| Hospitalizations | 67% of reported outbreak-associated hospitalizations |
| Deaths | 93% of reported outbreak-associated deaths |
The percentages are shares within reported WBDOSS outbreaks and outcomes, not measures of individual population risk. CDC, “2015 Waterborne Disease Outbreaks Annual Surveillance Report” combines confirmed and suspected etiologies in several summaries.
For the 2013–2014 period, CDC reported 42 drinking-water-associated outbreaks, causing at least 1,006 illnesses, 124 hospitalizations and 13 deaths in the United States. Legionella was associated with 57% of outbreaks and 13% of cases, but 88% of hospitalizations and all 13 deaths in that report.
CDC, “Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water — United States, 2013–2014” includes confirmed and suspected outbreak etiologies and emphasizes the limits of voluntary surveillance.
Recreational-Water Disease Statistics and Settings
Recreational water includes treated venues such as pools, hot tubs and splash pads, as well as untreated lakes and reservoirs. In 2015, recreational water was associated with 47 of 82 reported U.S. waterborne outbreaks, causing 787 cases, 23 hospitalizations and one death.
Cryptosporidium caused 22 of the 47 recreational-water outbreaks and 360 of the 787 reported cases. Norovirus caused 263 reported cases, while Legionella caused 13 of the 23 hospitalizations.
| Recreational-water category, 2015 | Reported outbreaks | Reported cases |
|---|---|---|
| Treated water | 40 | 490 |
| Untreated water | 7 | 297 |
| Pools within treated water | 18 | 286 |
| Lakes or reservoirs within untreated water | 6 | 279 |
These venue counts are reported outbreak totals, not venue-specific risk rates. CDC, “2015 Waterborne Disease Outbreaks Annual Surveillance Report” notes that the treated category includes pools, hot tubs and splash pads.
Seasonality, Exposure Routes and Surveillance Limits
Reported U.S. waterborne outbreaks were seasonally concentrated in 2015: 42 of 82 occurred during June–August. Seasonality can reflect both exposure patterns and reporting capacity, so it should not be interpreted as a direct incidence rate.
The largest reported settings included 18 outbreaks at hotels or motels, 8 at outdoor recreational areas, and 7 at hospitals or healthcare facilities. Communities or municipalities accounted for 6 outbreaks and 283 cases, while long-term care or assisted-living facilities accounted for 5 outbreaks and 78 cases.
Among the 82 reported 2015 outbreaks, bacteria were implicated in 54% and parasites in 35% when confirmed and suspected etiologies were combined. The categories may not sum to 100% because of other causes and classification details.
Across the dataset, three distinctions are essential when interpreting waterborne disease statistics:
- WHO WASH figures estimate disease attributable to inadequate water, sanitation and hygiene and are broader than drinking-water infection counts.
- CDC national burden figures are modeled for 2014, cover 17 pathogens and multiple exposure routes, and include uncertainty for pathogen-specific estimates.
- CDC outbreak figures are voluntary surveillance counts requiring linked cases and implicated water exposure; they do not represent all infections or population incidence.
CDC, “2015 Waterborne Disease Outbreaks Annual Surveillance Report” is the source for the 2015 outbreak totals, seasonal pattern, settings and confirmed-or-suspected etiology summaries.