North Carolina Division of Public Health officials on Monday adjusted downward the number of E. coli illnesses being investigated there.

Twenty-four cases, including nine confirmed and 15 suspect cases, are now being reported, compared with 26 announced in the health department’s previous update. Two illnesses listed before are in fact not part of the outbreak, the health department said.

Of the five people who have been hospitalized, four are children.

The source of the outbreak has not been determined but health authorities are still exploring the possibility that the common link is attendance at the recent state fair.

At a press briefing Monday, state epidemiologist Dr. Megan Davies told reporters that all 24 of the case patients will be re-interviewed. Staff members have already interviewed about 70 people who attended the fair but did not show signs of illness.