Health officials are investigating an outbreak of intestinal illness that has sickened dozens and is "likely linked" to salads at McDonald's.
McDonald's said Friday it's voluntarily pulling salads from about 3,000 locations in 14 states, primarily in the Midwest, until it can switch to a different lettuce supplier.
The Centers for Disease Control and Prevention says it's found 61 cases of cyclosporiasis among people located in Iowa, Illinois, Minnesota, Missouri, Nebraska, South Dakota and Wisconsin who had eaten salads at McDonald's.
Two people have been hospitalized and no deaths are linked to the outbreak.
Illinois' health department said Thursday that it confirmed about 90 cases of cyclosporiasis since mid-May. The same day, an Iowa health official said the state found "15 Iowans who ate McDonald's salads in late June to early July prior to getting ill."
The Food and Drug Administration says cyclosporiasis is associated with symptoms including: "diarrhea, with frequent, sometimes explosive, bowel movements. Other common symptoms include loss of appetite, weight loss, stomach cramps/pain, bloating, increased gas, nausea, and fatigue. Vomiting, body aches, headache, fever, and other flu-like symptoms may be noted."
Cyclosporiasis is caused by the microscopic Cyclospora cayetanensis parasite that can contaminate food or water, according to the FDA.
The CDC said as of Friday, it confirmed 227 cases of cyclosporiasis in people in Iowa, Minnesota, Wisconsin and Michigan who consumed now-recalled Del Monte vegetable trays. Del Monte recalled the trays in early June, the FDA says, and the agency says the Del Monte outbreak is not related to the one involving McDonald's.
Sickness caused by Cyclospora is "relatively rare in the U.S." according to NPR's Michaeleen Doucleff. "Most food poisonings here are caused by bacteria or viruses, like E. coli and norovirus. In contrast, Cyclospora is a protozoan, which typically hangs out in tropical and subtropical regions."
Standard treatment of sulfa drugs can "wipe out the infection quickly," Doucleff notes. The CDC says most people with healthy immune systems will recover from Cyclospora infection without treatment, though health officials recommend anyone with diarrhea that has lasted more than three days to contact a health care provider.