More than 250 people in at least six states have come down with a stomach bug that could be linked to foodborne illness.
The Centers for Disease Control and Prevention says the cyclospora infection causing diarrhea and other flu-like symptoms has been reported in Iowa, Nebraska, Texas, Wisconsin, Georgia and Connecticut. The CDC said 10 people have been hospitalized and most of the reported illnesses occurred from mid-June to early July.
About 50 people have been diagnosed with the infection in North Texas.
Tarrant County health officials reported 12 cases as of July 24. Dallas County reported 13 cases as of July 23. Collin County reported 17 cases, and Denton County reported 8 cases.
The Food and Drug Administration is investigating the cyclospora infections. The parasite is most often found in tropical or subtropical countries and has been linked to imported fresh produce in the past.
The illness is usually spread when people ingest foods or water contaminated with feces. The agency said it isn't yet clear whether the cases from all of the states are linked.
The CDC is asking people infected with the parasite to tell it about what type of produce they have eaten and from where they got it. The FDA is also dedicated investigators to find the source of the parasite.
County health officials say washing produce could significantly reduce the chances of getting the infection.
"To decrease the risk of eating fresh produce it is important to thoroughly rinse your fruits and vegetables several times," said Dr. Christopher Perkins, Dallas County Health and Human Services medical director. "Even when cooking vegetables, it is critical to clean them beforehand."
The number of reported illnesses expanded from more than 200 to more than 250 on Tuesday, according to the CDC. The CDC added Georgia and Connecticut to the list of affected states.
Doctors do not know if the outbreak is over yet, in part because cyclospora infections can sicken someone for weeks.
""So the average length of time someone is going to be sick with cyclospora is going to be 57 days of diarrhea -- that's a long time to be sick," said Heather Meador, a nurse in Linn County in Iowa.
The CDC said it is investigating additional illnesses, and the number of those sickened could grow.
NBC 5's Julie Fine contributed to this report.