Waterborne Disease Risk Assessment Program

New York City’s Waterborne Disease Risk Assessment Program was established to:

• obtain data on the rates of giardiasis and cryptosporidiosis, along with demographic and risk factor information on case patients
• provide a system to track diarrheal illness to assure rapid detection of any outbreaks
• determine the contribution (if any) of tap water consumption to gastrointestinal disease

This program began in 1993 and is jointly administered by the New York City Department of Health and Mental Hygiene and the New York City Department of Environmental Protection. For general drinking water monitoring information, visit Drinking Water Monitoring.

Each year, we publish a Waterborne Disease Risk Assessment Program Annual Report as a deliverable under the Filtration Avoidance Determination. The report provides an annual overview of program achievements as well as data results from the Active Disease Surveillance Program. In addition, the report summarizes trends observed in each of the program’s distinct and complementary gastrointestinal (GI) outbreak detection systems: gastrointestinal disease observed in sentinel nursing homes, number of stool specimens submitted to clinical laboratories for microbiological testing, hospital emergency department visit reports, and volume-of-sales of non-prescription anti-diarrheal medication. Each of these systems adds to the comprehensiveness of the program, ranking it among the best public health surveillance systems for water quality in the nation.

Although these syndromic surveillance systems do not identify specific routes of exposure, nor explicitly giardiasis or cryptosporidiosis, they do serve as important and sensitive tools to help detect GI outbreaks. While some localized GI outbreaks in NYC have been detected through these monitoring systems, none of these outbreaks have been found to be attributed to waterborne agents.