Cyclospora outbreaks have been reported across the United States in recent years, especially during the summer when contaminated fresh produce has been linked to illness. That broader pattern is now in focus in Michigan, where state officials said on July 1 that more than 170 cases were reported in just nine days and the CDC is part of the wider outbreak response.
Michigan reports 170-plus cases in 9 days
The Michigan Department of Health and Human Services and the Michigan Department of Agriculture and Rural Development said they are investigating a large and growing outbreak of cyclosporiasis. As of Tuesday, June 30, more than 170 cases had been reported in the past nine days, according to the state announcement released July 1. Michigan typically identifies about 50 cyclosporiasis cases in an entire year, which shows how unusual this spike is.
State officials said the illness is caused by the parasite Cyclospora cayetanensis. Symptoms can begin two to 14 days after exposure and may include frequent watery diarrhea, loss of appetite, weight loss, abdominal cramps, bloating, nausea and a low-grade fever. The state’s chief medical executive, Dr. Natasha Bagdasarian, said additional cases are expected based on the number already identified in a little over a week.
The CDC says it monitors cyclosporiasis in the United States and helps state health departments identify and investigate outbreaks to prevent additional cases. Federal guidance also notes that no one fully knows how Cyclospora gets into food and water, which means the investigation is still focused on finding a shared exposure.
Where the outbreak stands in Michigan
The highest confirmed county total is in Monroe County with 70 cases, followed by Lenawee with 33 and Washtenaw with 21, according to Michigan’s July 1 update. Wayne County had 12 cases, while Jackson and Shiawassee each had seven. Another 24 cases were reported across 11 other counties and the City of Detroit.
Michigan officials said the known patient ages range from 8 to 84, with an average age of 44.3 and a median age of 41. Those figures show the outbreak is affecting both children and adults. Officials also said not all cases identified in the last nine days may be connected to the same outbreak.
What is not yet known is the source. The state said no cause has been identified at this time, and officials are interviewing patients to look for a common exposure. The state has not released a list of specific foods, stores or restaurants connected to the illnesses.
Why officials are focused on produce and food handling
Michigan said Cyclospora is commonly found in developing countries and spreads through food or water contaminated with feces. In recent years, U.S. outbreaks have occurred after people ate contaminated fresh produce, especially during summer months. State officials also said cyclosporiasis is not known to spread from person to person.
CDC prevention guidance says the best known way to avoid cyclosporiasis is to avoid food or water that may be contaminated with feces. The agency also says routine chemical disinfection or sanitizing of food or water is unlikely to kill Cyclospora in endemic tropical and subtropical areas. That is one reason outbreak investigations often center on where produce was grown, handled or washed.
For residents, the practical guidance from Michigan and the CDC is straightforward: wash hands with soap and water before and after preparing produce, wash fruits and vegetables under running water, scrub firm produce like cucumbers and melons, and refrigerate cut produce within two hours. State officials said the public health investigation is ongoing as they work to identify the source and prevent additional illness.
