Cyclosporiasis outbreak spreads across 18 US states; Michigan reports 170 cases in under two weeks

A parasite known to cause severe diarrhea has been detected across 18 states, with a particularly significant outbreak in Michigan. While the source of the infections remains unidentified, health experts are urging precautions with fresh produce and good hygiene practices to reduce the risk of illness.

What Is Cyclosporiasis?

Cyclosporiasis is a form of food poisoning caused by the parasite Cyclospora cayetanensis. According to the Cleveland Clinic, it can lead to "watery, and sometimes explosive, diarrhea and other stomach problems," and in some cases, a low-grade fever. Symptoms may appear anywhere from two to 14 days after consuming contaminated food or water.

Although the parasite is more common in tropical regions, 145 cases were reported in the United States by mid-June.

"People became sick after eating food in the United States and did not report any travel during the 14 days before they got sick," the CDC stated. Infected individuals range in age from 5 to 86 years old. While some cases have required hospitalization, no deaths have been reported.

Growing Concern in Michigan

Concern has escalated as Michigan—which typically records about 50 cases of cyclosporiasis per year—has reported at least 170 cases in under two weeks, according to CNN.

The CDC noted that there is "currently no evidence of a single, multistate Cyclospora outbreak linking all cases." Instead, researchers are "working to identify various potential clusters and sources of illness in multiple states."

In addition to Michigan, cases have been reported in the following states:

• Alaska
• Colorado
• Connecticut
• Illinois
• Florida
• Georgia
• Louisiana
• Massachusetts
• New Jersey
• New York
• North Carolina
• Ohio
• Pennsylvania
• Tennessee
• Texas
• Virginia
• Wisconsin

Possible Sources

Investigators have not yet identified the cause of the current outbreak. However, David Freeman, a professor emeritus of infectious diseases at the University of Alabama at Birmingham, told CNN that the most likely culprits include:

• Cilantro
• Basil
• Plants used in salads or as garnishes
• Strawberries, blueberries, melons, and other field-grown produce

Prevention and Treatment

Taking precautions is essential to preventing infection. Cooked food is safer than fresh produce, as heat can kill the parasite. Washing produce can also help reduce the risk.

"Thoroughly washing hands and kitchen counters, as well as cutting surfaces, is important too," CNN reported, but noted that "bleach doesn't kill the parasite." Instead, "handwashing with soap and water and a follow-up with an alcohol-based hand sanitizer are safer bets."

If infected, antibiotics can help clear the infection. Without treatment, "symptoms may last for a month or longer," increasing the "risk of severe dehydration and other complications," according to the Cleveland Clinic. With proper diagnosis and treatment, most people recover within one to two weeks, though occasional bouts of diarrhea may persist for up to a month.