The news came as Wake County health officials announced they were handing the investigation into the source of the poisoning to the state.
Here's the breakdown:
- Cleveland Co. 1
- Durham Co.1
- Franklin Co.1
- Johnston Co.1
- Sampson Co.6
- Wake Co.11
Four of the 21 are hospitalized. They are all children.
Seven of the ill in Wake County are confirmed E. coli poisoning cases. Four are suspected.
Officials said some of the new cases attended the North Carolina State Fair.
On Wednesday, Wake County health officials said that eight of nine recent E. Coli cases involve people who attended the fair.
They cautioned that the investigation was still in the early stages and they have no indication the fair was the source.
They said the investigation could take days or weeks to complete.
Symptoms of E. coli poisoning include diarrhea, abdominal cramping, pain or tenderness and nausea and vomiting.
For more information about E. coli, visit http://epi.publichealth.nc.gov/gcdc/ecoli.html.