"Romaine lettuce from the Yuma growing region [of Arizona] is past its shelf life and is likely no longer being sold in stores or served in restaurants," officials at the U.S. Centers for Disease Control and Prevention said in a statement released Friday. Image copyright AFP/Getty Image caption No clear source for the outbreak has yet been identified

Five people have now died in a major E. coli outbreak in the US involving romaine lettuce, with 197 cases reported across 35 states. However, most of the new cases are people who got sick two or three weeks ago, when the contaminated romaine lettuce was still available for sale and in people's homes, the CDC reported. “Some people who became sick did not report eating romaine lettuce, but had close contact with someone else who got sick from eating romaine lettuce.”

Most E. coli bacteria are harmless, but one strain, called E. coli O157:H7, can cause severe disease. People who get sick from toxin-producing E. coli come down with symptoms about three to four days after swallowing the germ, with many suffering bloody diarrhea, severe stomach cramps and vomiting. Romaine is no longer being grown in the Yuma area and the CDC and the Food and Drug Administration both said lettuce grown elsewhere is not involved in this outbreak.The FDA said it may take a while to find out how the bacteria got into so much of the romaine lettuce supply.
The CDC reports that five people have died and 197 have been hospitalized in the United States, in the largest incidence of E. coli since the 2006 North American E. coli outbreak.