In the fight against foodborne illness, health officials have discovered a potentially powerful new tool: social media.

Have you ever gotten food poisoning from restaurant food? If so, you probably warned your friends, maybe on Facebook. Maybe you also sounded the alarm on a restaurant review site or on Twitter. Some experts think this trend could help identify food poisoning outbreaks early on, before more people get sick.

The Centers for Disease Control and Prevention notes that although that an estimated 48 million Americans suffer from food poisoning each year, only a fraction of such illnesses are diagnosed and reported.

While people with food poisoning don't usually bother to contact their local health department, they do take to the Internet. One place they're doing it is Yelp, which offers crowd-sourced reviews of restaurants and other local businesses. During a recent Shigella outbreak at a seafood restaurant in San Jose, California, that’s where many consumers turned, posting comments about what they ate and what symptoms they experienced.

Related: Shigella Infection Sickens Hundreds in California

As Kaiser Health News reported, attorney Andrés Guerra was one of the people who wrote about his case of food poisoning, posting his review after being hospitalized with Shigella. “I’m not trying to slander any business,” Guerra said, noting that his review had been deleted. “I just want no one else to go through this.”

In fact, some health departments are combing through Yelp reviews to identify outbreaks of food poisoning. The New York Department of Health and Mental Hygiene, for instance, has been using data-mining software to scan Yelp reviews for evidence of potential outbreaks since 2012.

Related: Is Your Insurance Company Using Social Media to Snoop on You?

Other initiatives to track foodborne illness are leveraging Twitter.

A project of the Smart Chicago Collaborative, Foodborne Chicago, has been scanning Chicago-area tweets since 2013 for mentions of food poisoning. Researchers say they have to weed out a lot of irrelevant tweets, such as the cluster of tweets about Justin Bieber canceling a concert in Argentina due to food poisoning. But the group’s efforts have resulted in more than 1,100 reports of foodborne illness being filed with the Chicago Department of Health since the project’s launch.

A new website, Iwaspoisoned.com, asks users to identify the location of the restaurant, the menu items they consumed and the symptoms they experienced. Founder Patrick Quade created the website after his sister was stricken with food poisoning while pregnant. Because the site isn’t used for restaurant reviews, there is, in theory, less incentive for abuse. “Health departments have reached out [asking] for targeted data,” Quade says, which a custom reporting feature delivers.

There’s one thing all of these projects have in common: The more data they have to work with, the better their chances of identifying an outbreak. So next time you find yourself laid out by a case of food poisoning, contact your local health department, but also jump online. Don’t get abusive or attack the restaurant you’re naming, but do share details that could alert officials to a problem.

Related: How to Complain on Social Media without Getting Sued (or Worse)

Matt Baker, who hails from Kentucky, writes about nature and travel for regional and national publications.