Public health authorities in Michigan announced Monday that infections from a foodborne parasite have drastically multiplied, with recorded cases soaring to 2,640. No fatalities have been reported.

The Michigan Department of Health and Human Services (MDHHS) disclosed that the state’s total caseload spiked by more than 1,000 cases since Friday, marking the most severe cyclosporiasis outbreak in state history. The state typically records only about 50 cases during an entire year, underscoring the unusual scale of the current outbreak. Most illnesses have been concentrated in southeastern Michigan, although cases have been identified in numerous counties as investigators continue searching for the source. A neighboring response is also underway in northern Ohio, where local clinicians have tracked hundreds of matching cases.

The exact origin of the microscopic organism, known as Cyclospora cayetanensis, has not yet been determined by investigators. According to state epidemiologists, the infection is typically contracted by consuming fresh produce or water contaminated with fecal matter. While federal and state authorities continue traceback investigations, the Michigan health department has noted that prior North American outbreaks of the parasite have been linked to imported fresh produce, including pre-washed bagged salad mixes, cilantro, basil, green onions, snow peas, and raspberries.

The U.S. Centers for Disease Control and Prevention (CDC) reported that the multi-state surge encompasses at least 29 states, noting that cyclosporiasis thrives during hot summer weather, typically spanning from May through August. Because tracing complex national agricultural supply chains can take months, identifying a singular point of contamination remains a challenge. State medical executives noted that the tracking process relies on interviewing patients and matching genetic markers from laboratory samples to determine if illnesses originated from the same distributor.

Individuals infected by the parasite often experience sudden and relentless watery diarrhea, abdominal cramps, bloating, nausea, and fatigue. Health experts caution that while the condition is rarely fatal, the severe dehydration it causes poses a serious threat to vulnerable populations, including the elderly, young children, and those with compromised immune systems. If left untreated, the symptoms can persist for several weeks or recur multiple times, though the infection is highly treatable with standard antibiotics.

In response to the growing crisis, health officials are urging commercial kitchens and individual consumers to implement rigorous food safety protocols. The state recommends that residents purchase whole heads of lettuce instead of pre-washed salad kits, instructing them to discard the outer layers and thoroughly rinse the remaining leaves under running water. Because the parasite can easily hide in the textured surfaces of items like fresh raspberries, basil, and cilantro, authorities advise cooking these ingredients whenever possible to eliminate the pathogen.

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