GOLDEN, Colo. - E. coli is to blame for the outbreak of food-borne illness among dozens of inmates at a county jail, sheriff’s officials said. About 70 Jefferson County inmates have reported symptoms including severe abdominal cramping, diarrhea, vomiting and a low-grade fever. Officials said that 37 inmates were still ill and that one was hospitalized Wednesday. An investigation began Friday, they said.

County health officials were awaiting further test results to determine what strain of E. coli made the inmates ill, said Mark Johnson, head of the health department for the county just outside Denver.

Health officials were trying to determine what food might have been contaminated and how.

The bacteria can be spread by unwashed hands or contact with fecal matter.

Historically, outbreaks have been tied to eating undercooked ground beef, contaminated water, lettuce and numerous other foods, including poultry.

Those infected typically can recover without complications.