A spokeswoman for the state Division of Public Health said Friday at least 23 of the people with suspected or confirmed E. coli attended the fair, CNN reported. But Julie Henry said investigators have not been able to narrow down the potential source to a specific place at the fair.
A 2005 E. coli outbreak was traced to a petting zoo at the fair.
About half of the cases are children, she said, including four with confirmed infections. Three of them are on dialysis because of liver failure.
The first cases were reported Oct. 15, two days after the fair opened in Raleigh, Henry said. Almost a million people attended the fair, which ran through Oct. 25.
While many strains of E. coli are harmless, the pathogenic strains can cause serious and sometimes fatal disease. The most common sources of E. coli in the United States are undercooked ground beef, unpasteurized milk or juice and leafy vegetables.