Planning a Trip to Michigan This Summer? A Parasitic Infection Is Spreading Fast and Officials Want Travelers to Know
Summer travel often overlaps with the seasonal rise in foodborne illnesses across the U.S. In Michigan, state health officials said this week that a fast-growing cyclosporiasis outbreak has pushed confirmed cases past 300.
Michigan confirms a much larger-than-usual outbreak
The Michigan Department of Health and Human Services said more than 300 cases of cyclosporiasis had been confirmed in the state as of Thursday. MDHHS told ABC News that Michigan typically sees about 50 cases in an entire year, making the current total unusually high for this point in the season.
MDHHS spokesperson Lynn Sutfin said the department is working with state and local partners to identify the source of the outbreak. Sutfin said officials are trying to determine what is making so many people sick as quickly as possible, but the source had not been publicly identified as of Thursday.
Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora cayetanensis. According to the Centers for Disease Control and Prevention, the parasite usually spreads through food or water contaminated with feces.
What travelers in Michigan should know right now
The confirmed outbreak is centered in Michigan, and state officials have not released a full public breakdown of cases by county. What is confirmed is the statewide count of more than 300 cases, along with MDHHS’s statement that the total is well above the state’s usual annual pattern.
Nationally, the CDC reported 145 cases in 17 states outside Michigan as of June 15, with at least 20 hospitalizations. That makes Michigan’s outbreak notable by scale, but officials have not yet said whether one product, one retailer or one event is responsible.
For visitors, timing matters because doctors told ABC News that cases typically begin rising in May. The CDC says symptoms usually start about one week after infection, though the range can be from 2 days to 2 weeks.
Why cases rise in summer and what symptoms are being watched
Doctors told ABC News that cyclosporiasis has often been linked to fresh produce, including imported raspberries, basil, snow peas, mesclun lettuce and cilantro. Infectious disease specialist Dr. Peter Chin-Hong said the U.S. used to see many travel-related or imported-produce cases, but more domestic cases are now being seen as well.
Dr. Zoe Weiss of Tufts Medical Center said the most common symptom is explosive watery diarrhea. Weiss said other symptoms can include cramping, bloating, low-grade fever, nausea and vomiting, while Sutfin said people who are immunocompromised, including some cancer and organ transplant patients, may face more severe effects.
The CDC says treatment is typically the oral antibiotic trimethoprim-sulfamethoxazole, sold under brand names including Bactrim, Septra and Cotrim, taken for 10 days. Health officials also said washing produce, cutting away damaged areas and refrigerating pre-cut fruits and vegetables can reduce risk while the Michigan investigation continues.
