After a particularly bad restaurant meal, you may be moved to post a review on the website Yelp, warning other diners. But now someone else is listening in: New York City health officials, who may try to track you down if you complain that the meal made you sick.

The federal Centers for Disease Control and Prevention released a report on Thursday saying that the city’s Department of Health and Mental Hygiene had completed a pilot project that used Yelp reviews to help identify unreported outbreaks of food-borne illness.

Using a software program developed by Columbia University, city researchers combed through 294,000 Yelp reviews for restaurants in the city over a period of nine months in 2012 and 2013, searching for words like “sick,” “vomit” and “diarrhea,” along with other details. After investigating those reports, the researchers substantiated three instances when 16 people had been sickened. Those people had eaten the house salad, shrimp and lobster cannelloni, and macaroni and cheese spring rolls at three restaurants that the agencies are not identifying.

Officials said the project, which will continue, helps identify public health issues by using social media and big databases, like Google Flu Trends and Twitter, to find reports of flu and other concerns. Yelp allows them to track down individuals, and quickly; diners who suffer food-related ailments commonly do not report them.