Foodborne illness outbreaks tied to contaminated produce show up across the U.S. every year, especially in the warmer months. In Michigan, state health officials are now tracking a much larger-than-usual outbreak of cyclosporiasis, a parasitic intestinal infection that has already sickened more than 300 people.
Michigan reports more than 300 confirmed cases
The Michigan Department of Health and Human Services said Thursday that more than 300 cases of cyclosporiasis have been confirmed in the state. MDHHS told ABC News that Michigan usually sees about 50 cases in an entire year, which puts the current total at roughly six times the normal annual count.
Lynn Sutfin, a public information officer for MDHHS, said the department is working with state and local partners to identify the source of the outbreak. She said officials are trying to find the cause “as quickly as possible” because so many people became ill in a short period.
Cyclosporiasis is caused by Cyclospora cayetanensis, a parasite that spreads through food or water contaminated with feces, according to the Centers for Disease Control and Prevention. The CDC said it can take about one week after infection for symptoms to begin, though that window can range from 2 days to 2 weeks.
What is known in Michigan, and what is not yet known
What is confirmed in Michigan is the scale: more than 300 cases as of Thursday, according to MDHHS. What is not yet known is the specific source, and the state has not identified one food item, brand, retailer, or water system as the cause of the outbreak.
The CDC said foodborne outbreaks of cyclosporiasis have previously been linked to imported fresh produce, including raspberries, basil, snow peas, mesclun lettuce, and cilantro. Even with those past examples, officials have not said that any of those items are responsible in Michigan’s current outbreak.
Outside Michigan, the CDC reported 145 cases in 17 states as of June 15, with at least 20 hospitalizations. Michigan’s outbreak is separate in scale from that multistate count, and state officials have not released a public breakdown by county or a full exposure list.
Why officials are focused on food and water right now
Doctors told ABC News that cyclosporiasis cases usually begin rising in May, so the timing of the Michigan outbreak fits the normal seasonal pattern. Still, infectious disease specialist Dr. Peter Chin-Hong said the Michigan case count is notably high compared with what health officials typically expect.
Chin-Hong said the U.S. used to see many more infections linked to travel outside the country or imported fruits and vegetables, but now more domestic cases are being recognized. Dr. Zoe Weiss of Tufts Medical Center said person-to-person spread is very unlikely because the parasite needs days to weeks in the environment before it becomes infectious.
For Michigan residents, the main symptoms officials are watching for include watery diarrhea, cramping, bloating, low-grade fever, nausea, and vomiting. MDHHS said people with weakened immune systems, including some cancer patients and organ transplant recipients, may face more severe illness while the source investigation continues.
