Comment on this storyCommentMost of those sickened by E. coli in a recent outbreak in the Midwest ate at a Wendy’s restaurant in the week before their symptoms started, the Centers for Disease Control and Prevention said Friday.Though the CDC hasn’t conclusively pegged the fast food chain as the source of the infections, most of those sickened reported having eaten sandwiches there garnished with romaine lettuce. The chain’s restaurants in the region have stopped using the lettuce in sandwiches as a precaution, the Columbus-based company said in a statement.“While the CDC has not yet confirmed a specific food as the source of that outbreak, we are taking the precaution of removing the sandwich lettuce from restaurants in that region,” the statement said. “The lettuce that we use in our salads is different, and is not affected by this action. As a company, we are committed to upholding our high standards of food safety and quality.”At least 65 people have fallen ill across Ohio, Michigan, Indiana and Pennsylvania, including 10 who have been hospitalized, according to the CDC and Michigan authorities. No one is known to have died.CDC reports ‘fast-moving’ E. coli outbreak in Michigan and OhioCDC said Friday it is not advising that people avoid eating at Wendy’s restaurants or that people stop eating romaine lettuce. At this time, the agency said, there is no evidence to indicate that romaine lettuce sold in grocery stores, served in other restaurants or in people’s homes is linked to this outbreak.Several high-profile E. coli outbreaks have been linked to romaine lettuce. The Food Safety Modernization Act, which was signed into law in 2011, required farmers to test irrigation water, which can be contaminated with feces and bacteria. But the FDA has delayed its implementation.“E. coli outbreaks associated with lettuce, specifically the ‘prewashed’ and ‘ready-to-eat’ varieties, are by no means a new phenomenon,” said Bill Marler, a lawyer who specializes in foodborne illness cases. “In fact, the frequency with which this country’s fresh produce consuming public has been hit by outbreaks of pathogenic bacteria is astonishing.”What to know about E. coli symptoms and how to prevent infectionThe outbreak joins several other high-profile incidents of allegedly contaminated food this year. The FDA and CDC investigated a multistate outbreak of salmonella infections linked to certain Jif brand peanut butter products produced at a facility in Lexington, Kentucky, prompting many recalls. Abbott Nutrition recalled 5 million units of baby formula after at least four infants became sick, two of whom died. A listeria outbreak related to Big Olaf Creamery of Sarasota, Fla., led to ice cream recalls in many states, and organic strawberries were the source of a hepatitis A outbreak this spring.The source of the recent E. coli cases has been slow to emerge as state and local public health officials have interviewed people about the foods they ate in the week before they got sick.The CDC is trying to determine the full scope of the outbreak, which agency officials said could extend beyond the four known states. Public health investigators are using the PulseNet system, a national database of DNA fingerprints of bacteria that cause foodborne illnesses, to identify illnesses that may be part of this outbreak.The CDC estimates that 48 million people get sick each year in the United States, 128,000 are hospitalized, and 3,000 die of foodborne diseases.Foodborne illness results in $3 billion in health-care costs. Nearly half of the illnesses come from produce, according to the CDC. Then, in descending order, it is meat and poultry; dairy and eggs; and fish and shellfish.