At least six children in northeast Ohio have been infected by E. coli bacteria and the Medina County Fair is a possible source of the contamination, the state health department and Cleveland Clinic doctors said Monday.

The Ohio Department of Health said six cases of E. coli O157:H7 have been confirmed, with two in Cuyahoga County and one each Medina, Lorain, Wayne and Lake counties.

Doctors at the Cleveland Clinic put the number of cases at seven and said that overall 12 children have been treated in the area for bloody diarrhea, a symptom of E. coli contamination.

In addition to diarrhea, E. coli can cause severe abdominal cramping and _ in the most serious cases _ kidney failure. The bacteria kill an estimated 60 Americans each year and sicken an estimated 73,000 more, mostly children or the elderly.

The four children admitted to the Cleveland Clinic had attended the fair, which ran from July 31 to Aug. 6. The exact source of the infection has not been pinpointed.

E. coli can be spread through contaminated food or drinking water, contact with cattle manure or through person-to-person contact.