An outbreak of E. coli this past spring that sickened at least 12 people — and hospitalized seven of them — was caused by ground beef burgers cooked rare and medium-rare at restaurants, according to health department documents obtained by Food Safety News through records requests made over several months. This is the first time the exact cause of the outbreak, which occurred in April and May 2014, has been disclosed to the public. Public health experts speaking with Food Safety News say the outbreak is a stark reminder that undercooked ground beef poses a serious health risk and that consumers should be aware of the risk when ordering their burgers rare or medium-rare. The outbreak was first publicly reported by federal health authorities on May 19, 2014, with an announcement that ground beef produced by Detroit-based Wolverine Packing Company had sickened at least 12 people in 4 states. At the same time, the company and the U.S. Department of Agriculture (USDA) announced a recall of 1.8 million pounds of ground beef produced by Wolverine between March 31 and April 18, 2014. In notices to the public, health agencies warned consumers against eating undercooked ground beef since cooking burgers to only rare or medium-rare does not kill potentially harmful bacteria such as E. coli that might be present in the center. The recommended temperature for beef burgers is 160 degrees F, according to the outbreak announcement from the U.S. Centers for Disease Control and Prevention (CDC). What the public health warnings did not spell out, however, was that the illnesses were all connected to undercooked burgers served at restaurants, including an Ohio “gastropub” chain specializing in medium-rare burgers. That chain is Bar 145. The name is a reference to what the company’s website calls the perfect temperature for medium-rare burgers, 145 degrees F. Health department documents show that four of the five people sickened in the outbreak in Ohio ate medium-rare burgers at Bar 145 locations — three at the Toledo restaurant and one in the city of Kent. They came down with E. coli infections within days, and the illnesses prompted a restaurant inspection that found the beef came from Wolverine. Each of the 12 people with confirmed cases told health officials that they ate burgers at restaurants within the outbreak window, with eight of them specifically noting that they ate rare or medium-rare burgers. For every laboratory-confirmed case of E. coli infection, CDC estimates another 26 cases go unreported. Documents also show that the cases are all connected by an uncommon variety of E. coli O157:H7, one seen only once before in PulseNet, the national epidemiological database. That evidence adds up to a “really clear-cut” outbreak caused by the burgers, said Carlota Medus, principal epidemiologist with the Minnesota Department of Health. “It’s extremely unlikely that these illnesses could have been caused by a different source, based on the evidence,” she said. Two cases involved people who ate “very rare” burgers at Stella’s Lounge in Grand Rapids, MI. That beef also came from Wolverine. Other patients ordered burgers from a brew pub in St. Louis, MO, a burger bar in Farmington, MI, and a steakhouse in Kent, OH, not connected to Bar 145. Each of the restaurants received Wolverine beef, although documents do not specify how those burgers were cooked. According to Dave Theno, the many risks associated with serving rare ground beef mean that restaurants need to take a number of additional safety precautions — and these restaurants weren’t doing them all. Theno is a food-safety consultant and former vice president of technical services at Jack in the Box, where he was hired to rebuild the fast-food chain’s quality-assurance procedures following the 1993 E. coli outbreak from undercooked burgers that sickened hundreds of people and killed four children. “Obviously, serving rare ground beef is just super ill-advised,” he said. Understanding the risk While there’s nothing stopping consumers from ordering a rare burger, they should make sure they’re well-informed about the risks beforehand, said Benjamin Chapman, associate professor of food safety at North Carolina State University. Chapman is currently leading a nationwide study to assess how well restaurants inform their customers about the risks of undercooked burgers. Restaurants that serve undercooked meat or seafood are required by the federal food code to provide a warning on their menus and have the server verbally inform customers when they want something considered risky. While the study is still underway, Chapman said that he believes adults should be able to order a burger cooked however they want as long as they’re well-informed about the pathogenic risk. The jury is still out on whether or not they are. “The thing that I’m most interested in is whether the advisory is useful,” he said. “Does someone who goes into a restaurant and orders an undercooked meat product — are they given enough information to make a good decision based on their risk tolerance?” That question gets more tricky when the customer is a child or an elderly person. Both demographic groups are more susceptible to illness and permanent injury due to their relatively weaker immune systems. “The menu warning is a very weak control because you don’t really have any control,” said Roy Costa, owner of Environ Health Associates, a food-safety consulting firm for restaurants. Restaurants can’t guarantee an adequate level of food safety when leaving it up to servers to inform customers and make decisions on who should or shouldn’t eat a medium-rare burger, Costa said. Legal until someone gets sick The laws regarding serving undercooked ground beef put restaurants in a peculiar situation. While serving rare burgers is perfectly legal, it’s illegal to serve a burger that’s contaminated with E. coli. It’s considered an adulterated, defective product. But there’s no way for a restaurant to know that their beef is free of E. coli unless they take a number of major precautions. To start, restaurants need strict supplier control, Costa said. They should only buy beef from suppliers who perform microbial testing and provide certificates of analysis. On top of that, Costa recommends that the restaurants perform random testing of beef in addition to the supplier’s testing to make sure the supplier is doing things right. When asked if he knew of any restaurants performing both those steps, Costa said he did not. He knows of one gastropub that does require certificates of analysis from its suppliers for its medium-rare burgers, but they don’t perform their own additional testing, despite his recommendation. “You just need to have a strong operation overall. No cross-contamination,” Costa said. “You have to show you can meet the food code from A to Z, with really good supplier control and a very active person at the counter who’s empowered to decide who can and can’t eat these burgers. That’s the best you can do.” “That, and carry a $10-million insurance policy,” he added. Another option, Theno said, is to use cold-pasteurized beef. Through processes such as irradiation and electron-beam pasteurization, beef suppliers and restaurants can eliminate any bacteria and parasites from raw beef. They’re then free to cook the beef however they like without the threat of sickening customers, he said. While some restaurants and grocery stores now offer cold-pasteurized beef, the practice is still far from mainstream. “If you want to serve undercooked products like this, you’ve got to use cold-pasteurization,” Theno said. Who’s responsible? But what about the segment of the population who are fully aware of the risk and still want to enjoy a medium-rare, irradiation-free burger? If they get sick despite knowing the risk, are they responsible for their illness, or is the restaurant still on the line? Legally speaking, the restaurant is ultimately responsible. The disclaimers on the menu won’t absolve anyone in court, Theno said. “If someone wants to buy ground beef, take it home and cook it rare, that’s a personal choice,” he said. “But as soon as someone walks in my restaurant, I take responsibility for their health.” Even if restaurants cook food to order, they’re legally not allowed to sell products considered defective, which would include a contaminated burger, Costa added. Word travels fast through the food-safety world, and Theno said that when he heard about Bar 145 and their connection to the outbreak, he tried to get in touch with the owners to give them some advice, but he couldn’t get a return call. Food Safety News also contacted Bar 145’s Toledo location and spoke with a manager, but the owners did not return a call looking for comment. Ultimately, Costa said, consumers are the ones who risk illness and injury from a contaminated burger, and everyone should do the best they can to educate themselves on the risks and make informed choices. “You have to make a decision as a consumer if you’re going to expose yourself to a potentially life-threatening infection,” he said. “My advice is to do what you want, but understand what the risk is. Make an intelligent decision.” Theno, on the other hand, placed the final responsibility on restaurant owners. “Short of pasteurization, there’s no way to guarantee that there aren’t harmful microbes in ground beef,” he said. “Restaurant owners have a responsibility to protect public health and ensure no one gets sick from your products. They’ll tell you they have it under control, but they don’t.”