Wake County is investigating seven confirmed cases of illness due to E. coli bacteria exposure. And health officials were working Tuesday to determine whether there is any link between the cases - or whether there are more cases.

Six children and one adult were determined to have the disease, and four were sick enough to wind up in the hospital, said Julie Henry, spokeswoman for the state Division of Public Health. Two remained in intensive care Tuesday night.

"It doesn't mean there might not be more," Henry said.

Investigators did not know Tuesday what location or food source the victims might have had in common.

Dr. David Weber, a UNC-Chapel Hill physician who treats adult and pediatric infectious disease, said such illness can be food- or waterborne and be transmitted from person to person.

"It's a fecal-oral disease, and it's carried by many different animals," Weber said. "Classically when you track this back, there'll be an animal at the end of the chain."

Symptoms, treatment

Symptoms of E. coli include severe, sometimes bloody, diarrhea and painful abdominal cramps.

Health officials encouraged people with those symptoms to seek medical treatment and to call the Wake County Communicable Disease hotline at 919-250-4462.

Rehydration is an important part of recovery, Weber said.

"People can help prevent the spread of E. coli by practicing good personal hygiene," Wake County Community Health Director Sue Lynn Ledford said in a statement.

Preventive steps include:

Washing hands frequently.

Using safe food practices at home, such as washing hands before and after touching any raw food.

Rinsing fruits and vegetables.

Making sure foods that need refrigeration stay at a safe temperature.

Cooking meat to an internal temperature of 165 degrees.

Goldsmith: 919-829-8929