This Social Media Site Knows What Restaurants Will Make You Sick

Restaurateurs, beware: People who eat at your joints are brutally honest on Yelp, reporting on bad service, undercooked food, and yes, even diarrhea and vomiting after dining.

So the New York City Department of Health and Mental Hygiene decided to take advantage of those reviews and see if they could find outbreaks of foodborne illness, which are a sign that restaurants aren’t up to sanitation codes. From 294,000 restaurant reviews between 20012 and 2013, 893 were pulled out for containing red flag words like “sick,” “vomit,” “diarrhea” or “food poisoning.” Of these, more than half fit the conditions of a potential foodborne illness, including the fact that more than one patron reported symptoms, the symptoms occurred within 10 hours of the meal, the affected didn’t share any other meals before becoming sick, and so forth.

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Further investigation via phones calls and visits to the restaurants revealed three foodborne illness outbreaks affecting 16 people that were not reported to the health department. (In the study period, only 3% of the potential outbreaks identified by the analysis were actually reported.) In their report, published in the MMWR from the Centers for Disease Control (CDC), investigators found violations in food handling at the three establishments that included workers not washing their hands before handling food, not storing food in the refrigerator, and the presence of mice and roaches.

As tempting as it may be for health departments to start scouring Yelp or other online reviews for health code violations, the investigators say the process isn’t ideal since not all reviewers can be contacted, and having the reports reviewed and coded for further investigation by outbreak specialists is very labor intensive. Still, it shows that online restaurant reviews can be a treasure trove of potentially helpful information, and possibly identify restaurants that may consistently have problems with hygiene. Not to mention those that have terrible service.