Last year, a Rochester-area man died in an outbreak involving deli meats contaminated with Listeria. Most outbreaks remain hidden from the public, meaning you may walk into a restaurant and not know others have been ill. State and local officials say they announce outbreaks only when there's a risk that illnesses still are spreading. Health investigators from Minnesota, Wisconsin and the federal government have traced outbreaks to a variety of weak links in the food chain, from contaminated ingredients to malfunctioning equipment to mistakes by kitchen workers. Outbreaks can strike at well-run restaurants whose employees make one crucial mistake, or at dirty establishments rife with unsafe practices.
Home cooks can unwittingly start outbreaks in their own kitchens or at community events, too.
State officials say a cook unknowingly spread the virus to food and possibly water. In Minnesota and Wisconsin, half the outbreaks in recent years began with restaurants or caterers. They were the leading source nationally as well, starting two of every five reported outbreaks from 1988 to 1997, according to the U.S. Centers for Disease Control and Prevention. Cooks at home were to blame one of every five times, the CDC said. Experts believe the numbers may be skewed because food-borne illness victims are more likely to complain about a restaurant than about themselves, their church or a private club.