Michigan health officials are investigating a sharp rise in cyclosporiasis, a diarrheal illness caused by the parasite Cyclospora, with lettuce and other salad greens now the leading suspects.
The Michigan Department of Health and Human Services reported 3,309 cases as of July 14. In recent years, the state has usually logged about 50 cases. Forty-four people have been hospitalized this year, according to the department.
The outbreak is part of a wider national surge, but Michigan is seeing an unusually high concentration of cases. Based on interviews with more than 1,000 sick people in the state, MDHHS said the latest evidence points to leafy greens as the likely vehicle for infection.
What officials say they know
Cyclosporiasis is a food-borne illness that can cause urgent watery diarrhea, stomach cramps, and nausea. Those are not subtle symptoms, and an outbreak at this scale tends to leave investigators with two jobs: find common foods among patients and narrow the supply chain before more people are exposed.
MDHHS has said its interview data is now pointing toward lettuce and salad greens. The available figures do not identify a specific grower, distributor, or product. Taco Bell has also drawn attention in connection with the outbreak, but the details made public so far center on leafy greens rather than a confirmed restaurant source.
That distinction matters. A restaurant can be where contaminated food is served without being where contamination began. Greens often pass through farms, processors, distributors, and kitchens before they reach a customer. The public data described by MDHHS points to what people ate, not yet to a named point of contamination.
The scale is the signal
The jump from roughly 50 typical annual cases in Michigan to more than 3,300 by mid-July is the main reason this outbreak is getting attention. The hospitalization count, 44 people, shows that the illness has not been limited to mild cases.
For now, the confirmed facts are narrower than the alarm around the outbreak: Michigan has an unusually large cyclosporiasis surge, MDHHS has interviewed more than 1,000 affected people, and leafy greens are the prime suspect in that investigation.
This story draws on original reporting from Ars Technica.
