CBS: The Centers for Disease Control and Prevention are examining how Yelp can be used to track incidences of food poisoning that is not reported.
For the study, researchers mined approximately 294,000 Yelp reviews for New York City-based food establishments, written from July 1, 2012 to March 31, 2013. The reviews were analyzed with a software program created for the project, which identified potentially useful reviews with the keywords "sick," "vomit," "diarrhea" and "food poisoning." In order for the review to make the cut, two or more people needed to report illness at least 10 hours after their meal at the food establishment. This is the amount of time it takes for organisms to cause harm to the digestive system.
Read more here.