Consumer use of social media connects and informs communities about everything from local celebrations to impending natural disasters. This daily exchange of information is a rich resource in many different ways. For example, The New York Department of Health and Mental Hygiene (DOHMH) decided to investigate restaurant diners Yelp reviews to see if these were useful in pinpointing sources of food borne illness. The pilot study is detailed in this week s Mortality and Morbidity Weekly Report , published by the Center for Disease Control and Prevention.
Researchers of the study used a software program developed by Columbia University to examine 294,000 Yelp reviews of New York City restaurants between July 1, 2012 and March 31, 2013. The software program searched for select key words in reviews such as sick, vomit, or diarrhea. The analysis revealed three previously unidentified outbreaks that met DOHMH criteria, amounting to a total of 16 unreported illnesses.
Officials discussed the value of using an online-review system like Yelp to isolate food borne illness: Because food borne cases have a common exposure, a restaurant patron review-based system can identify small, point-source outbreaks that are not easily found by systems reviewing large sources of data, such as syndromic surveillance of emergency department visits, Google Flu Trends, and analysis of Twitter data for influenza and other public health trends. Most importantly, food borne epidemiologists can confirm reports because Yelp offers a way to follow-up with reviewers for interview.
The benefit of the Yelp system is only beginning to be realized. The researchers also noted limitations of the current study, including using a narrow focus to qualify incidents (thereby increasing the chance that the screening software might miss some cases), a prolonged time between review and interview of affected candidates, and the lack of identification of the infectious agents causing the outbreaks.
Officials and researchers plan to improve the review system before further implementation is carried out. The MMWR notes these changes as: To shorten the time from review to investigation, Yelp will provide daily instead of weekly review feeds, and, to increase sensitivity, the project will be expanded to include additional review websites. To improve response rates, DOHMH will offer a link to an electronic survey. Finally, DOHMH is exploring the possibility of linking multiple complaints pertaining to the same restaurant, using data from different review websites and DOHMH databases.