May 12, 2010 -- At least 30 people in four states have been sickened by a rare, virulent strain of E. coli in pre-shredded Romaine lettuce.

Twelve of the victims have been hospitalized, three with kidney failure. There have been no deaths to date. Some cases may have gone unreported because many labs do not test for the E. coli strain causing the outbreak. Michigan, Ohio, New York, and Tennessee have reported cases.

The contaminated Romaine lettuce was sold by restaurants and by grocery/deli salad bars and processed by Freshway Foods in Sidney, Ohio. An unopened bag of Freshway shredded Romaine lettuce was found to carry the E. coli with the same genetic fingerprints as E. coli isolated from patients.

Freshway has recalled all Romaine lettuce with a use-by date of May 12 or earlier.

Freshway got the lettuce from a farm in Yuma, Ariz. Another lettuce distributor, Vaughan Foods, has also recalled lettuce from the same farm. However, no illnesses have yet been traced to lettuce distributed by Vaughan.

Lettuce harvested from other areas does not appear to be associated with the outbreak, the FDA investigation suggests.

The illnesses occurred between April 10 and April 26. Because of a lag time between the last reported illness and testing, it's possible new illnesses may still be occurring.

People with E. coli infection usually get diarrhea and abdominal cramps for two to eight days after eating a contaminated food. Most people recover within a week, but some cases are much more severe and last much longer.

Some people may develop a form of kidney failure called hemolytic uremic syndrome or HUS. HUS tends to appear just as the diarrhea is getting better. Symptoms may include fever, abdominal pain, pale skin, fatigue, irritability, decreased urine output, unexplained bruises or bleeding from the nose and mouth, and swelling of the face, hands, feet, or body.

Seek immediate medical care if these symptoms appear after several days of diarrhea.