Health officials have identified two additional people who tested positive for E. coli and may be part of the recent outbreak traced to private gatherings held in the Fresno area.

Investigators are tracking down everyone who attended three private parties where tainted food might have been served.

Officials need to know what the people ate for breakfast, lunch and dinner for the past week, said David Luchini, division manager of communicable diseases for the Fresno County Community Health Department. He did not have an estimate on how long the interviews would take.

E. coli O157:H7 can cause a complication known as hemolytic uremic syndrome, or HUS.  HUS occurs in 5-10 percent of E. coli patients, and can cause damage to the kidneys, brain, pancreas, and central nervous system.