The number of cases of cyclosporiasis in Michigan has increased to 1,562, including 44 people who had been hospitalized, according to the latest statistics released Friday morning from the Michigan Health and Human Services Department.
Cases have been reported in 43 counties and the city of Detroit. The most, 215, have been reported in Monroe County. 160 cases are tied to Wayne County and 159 cases have been reported in Washtenaw County. Lenawee County is reporting 105 cases, while Oakland County has 88.
The source of the outbreak has not been identified, and health officials continue to work with local health departments and partners to investigate cases and provide updates as more information becomes available.
People experiencing gastrointestinal illness, such as sudden and ongoing diarrhea, are encouraged to contact their health care provider for testing and treatment. Cyclosporiasis is treated with antibiotics along with rest and drinking plenty of fluids to maintain hydration, according to the Michigan Health Department.
Cyclospora is a microscopic, spherical parasite that commonly causes watery diarrhea “with frequent and sometimes explosive bowel movements,” according to the U.S. Centers for Disease Control and Prevention. The illness, called cyclosporiasis, is not usually life threatening and is typically treated with antibiotics. Outbreaks tend to occur most often in the late spring and summer.
The heat-loving parasite infects the bowels and spreads through feces. In the past, people have been infected by consuming fruits or vegetables that were exposed to feces-contaminated irrigation water.
It’s less common than a number of other kinds of foodborne illnesses, including salmonella and E. coli. For years, few U.S. cyclospora outbreaks were reported each year. But the number started rising about a decade ago, with a particularly notable spike in 2018 and 2019. Experts attribute the increases to climate change and better detection.
How can you protect yourself from cyclospora?
People who have diarrhea that hasn’t gone away on its own within a few days should see a health provider and discuss the possibility of cyclospora, officials say.
The best way to prevent infection with a parasite is to avoid food or water that may have been contaminated.
Fresh produce should be thoroughly washed before being eaten. But be aware that cyclospora can really stick to some foods, so washing may not eliminate the risk of infection.
As Michigan officials investigate the potential source, they recommend consumers purchase whole heads of lettuce rather than prewashed, bagged lettuce or salad mixes, and remove the outer two to three leaves before washing the remaining leaves under running water.
They also say to cook vegetables when possible.
Comprehensive data on cyclospora outbreaks is lacking. But available information shows only a small number of documented outbreaks in the last 20 years have surpassed 1,000 cases. That short list includes a 1997 outbreak tied to Guatemalan raspberries that sickened more than 1,000 in the U.S. and Canada, and a 2019 outbreak linked to Mexican basil that sickened more than 2,400.
There are several reasons it's challenging to know the exact toll, said Melanie Firestone, a University of Minnesota foodborne illness researcher. Some tests used to check for types of food poisoning are not geared to detect cyclospora, “so there is a lot of underreporting when it comes to this,” she said.
Other challenges: Technicians aren't able to grow the parasite in labs, making it hard to draw evidence from contaminated produce. And it can be hard to figure out what food sick people had in common, because sometimes it’s a single ingredient that might be common in multiple recipes — like basil or cilantro.
Also, it's possible that food distributors may channel contaminated foods to both grocery stores and restaurants, making it hard to discern where tainted food came from. Investigations can take months and sometimes never find a clear source.
The Associated Press contributed to this story.
