The results of a pilot project conducted from July 2012 to March 2013 by the New York City Department of Health and Mental Hygiene along with Columbia University and the restaurant review website Yelp found that only 3% of the 468 reviews that were identified as possible cases of foodborne illness had been reported to city health officials.
Of those reviews, culled from an analysis of around 294,000 posts, officials investigated 129 possible outbreaks. Follow-up interviews on 27 of them led officials to three restaurants that caused as many as 16 illnesses.
In seven instances, the culprit was the restaurant's house salad, the report said. Three got sick from shrimp and lobster cannelloni. For the six others, it was macaroni and cheese spring rolls.
An environmental investigation of two of the establishments found multiple health code violations, including cross-contamination of food, improper sanitization of work surfaces, and improper cold storage of food items.
“Review websites might be a valuable source of data in the public health setting,” the report said.
The number of people who use sites like Yelp to complain about an illness acquired from eating at a restaurant may mean that a large portion of the public might be unaware of New York's 311 non-emergency system to report possible cases of foodborne illness, which receives an average of about 3,000 food-poisoning complaints each year, according to the report.
The researchers acknowledged their approach took significant manpower to analyze review and then follow up with investigation.
“Such reviews might be particularly useful if the website offers a way to reach reviewers for follow-up interviews,” they wrote.
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