• by Erik Sass , Staff Writer @eriksass1, June 3, 2014

If you live in New York City pay attention, because this concerns you -- or more specifically, the amount of time you spend in the bathroom after ordering in.

According to a report from the Centers for Disease Control and Prevention, the New York City Department of Health and Mental Hygiene is collaborating with Columbia University and online review platform Yelp to discover previously unreported outbreaks of foodborne illness by sifting Yelp reviews for evidence of, ahem, gastrointestinal distress. As you might expect that includes words like “diarrhea,” “food poisoning,” “sick,” and “vomit” (and, I imagine, any number of colloquial expressions for the same phenomena).

The project was inspired by the Health Department’s initial success tracing a foodborne disease outbreak back to a certain restaurant after a number of customers reported their condition on Yelp. So far, the CDC report says researchers from the Health Department and Columbia University have identified 893 Yelp reviews that warranted further investigation. In an alarming finding, just 3% of the complaints found of Yelp reviews had also been reported to the Health Department -- suggesting that in the past most cases of foodborne illness have simply gone unreported. The technical term for this trend is “gross.”

With all its self-reported health and behavioral data, social media obviously holds huge potential for charting (and maybe preventing or mitigating) disease outbreaks, and in fact a whole subspecialty of epidemiology called “infodemiology” has sprung up around this discipline. 

But it’s not just professional epidemiologists using social media to identify disease patterns. Last year I wrote about a case where Facebook users in Minnesota were able to identify tainted food as the source of a strep throat outbreak. And in another case the Los Angeles County Department of Public Health used social media to trace an outbreak of Legionnaire's Disease at a trade conference party held at the Playboy Mansion in Los Angeles. Overall, 79 people self-reported their illness on social media, via Facebook, blog comments, or tweets.