A growing outbreak of illness caused by the parasite Cyclospora has now sickened more than 3,000 people across Michigan and Ohio, prompting health officials to intensify efforts to identify the source of contamination. Early findings from the investigation suggest that lettuce or other salad greens may be linked to the outbreak, although authorities say other foods have not yet been ruled out.
Michigan has reported the overwhelming majority of cases, with more than 2,600 confirmed infections, while Ohio has identified more than 360 additional cases. Dozens of people have required hospitalization, although no deaths have been reported so far.
Cyclospora is a microscopic parasite that causes an intestinal illness known as cyclosporiasis. Symptoms commonly include watery diarrhea, stomach cramps, nausea, bloating, fatigue, loss of appetite, and flu-like symptoms. Illness often begins about a week after exposure and can last for weeks if left untreated. Some patients experience symptoms that disappear and later return.
State health officials say interviews with patients repeatedly identified lettuce and salad greens as common foods consumed before becoming ill. However, investigators have not yet identified a specific type of lettuce, grower, supplier, or distributor responsible for the outbreak. No recalls have been issued at this time.
Cyclospora outbreaks have historically been associated with fresh produce, including bagged salad mixes, cilantro, basil, raspberries, green onions, and snow peas. Because the parasite often contaminates produce before it reaches stores or restaurants, washing fruits and vegetables may reduce risk but may not completely eliminate the organism.
Health officials advise anyone experiencing persistent diarrhea or gastrointestinal symptoms to seek medical attention and specifically request testing for Cyclospora, as standard stool tests may not automatically screen for the parasite. The illness can typically be treated successfully with antibiotics when diagnosed promptly.
Public health agencies in both states continue to work with federal investigators to determine the source of the outbreak and prevent additional illnesses as the investigation remains ongoing.
