The Centers for Disease Control and Prevention has not yet identified a source of the bacteria, which since April 15 has sickened people in Alabama, Florida, Georgia, Tennessee, Louisiana and California.

A child in Louisiana died after being infected, officials said.

"The investigation is looking at both food and non-food sources as a part of the ongoing investigation," the CDC said in a statement on Friday.

The most recent report of illness from Shiga toxin-producing Escherichia coli 0145, commonly abbreviated as E.Coli, was on June 4, according to the agency.

In Louisiana, where no new cases have been reported since May, health officials initially thought the infection might be linked to a petting zoo. But that theory was dropped because only the child who died had been to the zoo, not any of the adults who were ill, said Dr. Raoult Ratard, Louisiana State Epidemiologist.

Five cases have been reported in Georgia, the most of any state. Investigators there "have detected no food items or environmental exposures that are statistically associated with illness at this time," the state's Department of Public Health said in a statement on Friday.

The spread of E.coli bacteria can be prevented by washing hands thoroughly after changing diapers or going to the bathroom and after contact with animals, the CDC said.

Meat should be cooked thoroughly, and people should avoid juices and dairy products that have not been pasteurized. The CDC also warns against swallowing water when swimming.

(Additional reporting by Lisa Baertlein; Editing By Colleen Jenkins and Andrew Hay)

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