Michigan investigates outbreak of more than 300 cyclosporiasis cases
Health officials in Michigan are probing a surge of over 300 cyclosporiasis infections across several counties, a number far above the state’s annual average.
More than 300 cases of cyclosporiasis have been reported in southeast Michigan within a week, prompting an investigation by the Michigan Department of Health and Human Services and the Michigan Department of Agriculture and Rural Development. The outbreak spans Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson and Livingston counties, with additional cases identified in 11 other counties, including Detroit. Michigan typically records about 50 cases per year. The age of those diagnosed ranges from 8 to 84, with a median age of 41.
Officials are working to identify a common exposure source. Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora, diagnosed through stool testing. Symptoms include watery diarrhea and can persist from several days to over a month if untreated; the incubation period is usually about a week but can vary from two days to two weeks.
The parasite spreads primarily through ingestion of food or water contaminated with feces. The CDC notes that the organism requires one to two weeks outside the body to become infectious, making direct person-to-person transmission unlikely. Preventive measures include washing hands with soap and water before and after handling raw produce, thoroughly rinsing fruits and vegetables under running water, and removing damaged portions before consumption.