It's too early to say that romaine lettuce is the source of an E. coli outbreak that has made at least 24 people in the U.S. and 40 in Canada sick, the Centers for Disease Control and Prevention said Wednesday.
"The likely source of the outbreak in the United States appears to be leafy greens, but officials have not identified a specific type of leafy greens eaten by people who became ill," the CDC said in a statement on its website.
The CDC added seven people to its count on Wednesday. The agency said it's hard to say the outbreak is over when the true source is not known, and blaming a single crop too soon could leave people at risk if something else is spreading the bacteria. Meanwhile, Canadian health officials said they traced the bacteria to romaine lettuce and have declared the outbreak over in the country.
The CDC's statement comes after Consumer Reports acted on its own last week to warn people not to eat romaine lettuce. The company said that even though it didn't have "100 percent certainty that romaine lettuce is the cause of the E. coli outbreak in the U.S., a greater degree of caution is appropriate given that romaine lettuce is almost always consumed raw."