Flint, Michigan – A microscopic parasite has turned a routine trip through the produce aisle into a public health concern across Michigan.
The numbers rose quickly. By July 4, state health officials had identified 572 cases of cyclosporiasis, while Genesee County reported 11 cases as of July 7. The largest clusters were found in Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland and Livingston counties.
The pace of the increase sharpened the concern. Michigan had reported more than 170 cases on June 30, meaning the statewide count more than tripled in four days. In a typical year, the state identifies about 50 cases, according to health officials.
For now, one major question remains unanswered: Where did the outbreak begin?
State and local epidemiologists are interviewing patients, gathering food histories and reviewing data, but no specific source has been identified. The illness is caused by Cyclospora, a microscopic parasite that reaches people through contaminated food or water. Unlike many common stomach illnesses, it does not usually spread directly from one person to another.
The most recognizable symptom is frequent, watery and sometimes explosive diarrhea. Infected people may also experience nausea, reduced appetite, stomach cramps, bloating, weight loss, vomiting and fatigue. Symptoms can begin as soon as two days after exposure or take more than two weeks to appear, although they most often develop within about a week.
Fresh produce has been connected to previous cyclosporiasis outbreaks in the United States and Canada. Foods identified in earlier investigations include bagged salad mixes, cilantro, basil, raspberries, snow peas and green onions. Health officials have not linked any of those foods to Michigan’s current outbreak, but the history offers a reminder that contamination may not be visible.
The Genesee County Health Department is urging residents to wash all fresh fruits and vegetables under clean running water. Firm produce should be scrubbed with a clean brush. Cooking food when possible adds another layer of protection because heating it to 158 degrees Fahrenheit, or 70 degrees Celsius, kills Cyclospora.
Anyone who develops symptoms should contact a medical provider. Residents with questions may also call the Genesee County Health Department’s Communicable Disease program at 810-257-1017 or email [email protected].
Additional updates and food safety guidance are available through the Michigan Department of Health and Human Services. General information about the illness, symptoms and prevention is available on the CDC cyclosporiasis webpage.
Until investigators find the source, the outbreak remains a moving target. For Michigan families, the practical response is simple: wash produce carefully, pay attention to symptoms and seek care when something feels wrong.