Michigan sees surge in cyclosporiasis cases as labs scramble for tests
More than 700 cases of the parasite-caused illness cyclosporiasis have been confirmed in Michigan, prompting health officials to investigate possible sources in fresh produce.
Michigan health authorities have confirmed over 700 cases of cyclosporiasis, a parasitic gastrointestinal infection, in the past ten days, with officials warning that the total could approach 1,000. The outbreak, which is concentrated in the southeastern part of the state, has also been reported in Ohio, North Carolina, Illinois and New Jersey.
"We’re pulling people’s grocery shopping lists," said Dr. Natasha Bagdasarian, chief medical executive for Michigan, describing the effort to trace the source of the illness.
The Food and Drug Administration and the Centers for Disease Control and Prevention are monitoring the situation, though an FDA spokesperson said the agency cannot yet determine whether the numbers are statistically unusual pending the investigation’s completion.
Cyclosporiasis is caused by the microscopic parasite Cyclospora, which is typically transmitted through contaminated fresh produce such as lettuce, berries, cilantro or basil. Symptoms include watery diarrhea, abdominal cramps, nausea and loss of appetite, and the infection can persist for weeks if untreated. Treatment usually involves the antibiotic Bactrim, and some patients have required hospitalization for dehydration, but no deaths have been reported.
"When we started seeing cases of persistent diarrhea showing up, we knew there’s something going on," said Dr. Brian Kaminski, vice president of medical affairs at ProMedica Health System, which has recorded 411 cases in southeast Michigan and northwest Ohio.
Testing capacity is strained; turnaround times have lengthened from about 24 hours to two or three days. Officials warn that continued delays may force clinicians to treat based on symptoms rather than confirmed laboratory results.
Public health officials are advising consumers to rinse produce thoroughly, remove outer lettuce leaves, and consider cooking foods when possible, as cooking is the only reliable method to kill the parasite. Freezing may reduce risk, but its effectiveness is not guaranteed.
The investigation continues as officials seek to determine whether the outbreak stems from a single source or multiple, geographically separate incidents.