Cyclosporiasis latest: 'Tenacious' diarrhea parasite lingers in Illinois

CHICAGO - Illinois officials are continuing to monitor an increase in cyclosporiasis cases that have been wreaking havoc across the Midwest.

Dr. Sharon Welbel, chair of the Division of Infectious Diseases with Cook County Health, said the parasite has received increased attention because of outbreaks, particularly in Michigan.

"So it's not something we'll be able to see on our food or in the water," Welbel said. "It's a microscopic parasite. The specific one that we're talking about is cyclospora cayetanensis, and it is transmitted via contaminated fresh produce or swallowing contaminated water, and it causes, as people have heard, this explosive diarrhea, bloating, cramping, less commonly fever."

Cyclosporiasis in Illinois

What to know:

According to Welbel, Michigan has reported more than 1,500 cases and dozens of hospitalizations. Illinois has also seen cases, though she said nearly half have been linked to travel outside the state.

Officials have not identified the source of the current outbreak.

Historically, U.S. outbreaks have been tied to fresh produce including cilantro, basil, raspberries, salad mixes, snow peas and green onions.

Welbel said people should wash their hands before preparing food and thoroughly rinse fresh produce under running water, physically removing as much contamination as possible.

She said those most at risk for serious illness include older adults, young children and people with weakened immune systems.

Symptoms typically appear two to 14 days after consuming contaminated food or water and often include watery diarrhea, bloating and cramping.

"If one has this sort of, you know, people call it explosive diarrhea, watery diarrhea, bloating, cramping, definitely contact a provider. There is an antibiotic. It's a sulfa antibiotic, a common one that we use is called Bactrim, that really is very highly effective at treating this, so that's the good news," Welbel said.

Dig deeper:

Unlike norovirus, Welbel said cyclospora is not easily spread from person to person because the parasite must mature outside the body before becoming infectious.

"It's much more tenacious. The good thing is that it isn't easily transmitted from person to person, because the organism has to mature outside of the body."

Doctors also warn the illness can last much longer than a typical stomach bug.

"Infection with this parasite, people can be sick for say two to four days or up to a month and even after that month period, if one gets better, it can relapse," Welbel said.