More than 450 people in 18 states have fallen ill with cyclosporiasis since early May, and investigators have yet to name a food source [1]. Michigan accounts for the majority of those cases — more than 300 in approximately 11 days — at a rate running six times the state's entire annual baseline [2].

As this paper reported Monday, the CDC had confirmed 145 cases across 17 states and noted that DOGE-era staffing reductions had slowed the investigation. Today's figures represent a 200-percent jump in the national count and a Michigan surge that has no obvious explanation yet — no recalled product, no linked restaurant chain, no named commodity [1].

What the illness is and how to recognize it

Cyclospora cayetanensis is a microscopic intestinal parasite. Infection causes watery diarrhea that is characteristically prolonged — lasting weeks if untreated — along with fatigue, nausea, abdominal cramping, and appetite loss. The symptom that should prompt a doctor's visit is diarrhea lasting more than a week, particularly in anyone who ate fresh produce, especially imported herbs, in the past 14 days [3].

A crucial diagnostic point: a routine stool culture ordered for acute diarrhea does not detect cyclospora. The parasite requires a separately ordered modified acid-fast stain or a Cyclospora-specific PCR test [2]. If you ask your physician for a stool test because of diarrhea, ask specifically whether it covers cyclospora — standard panels often do not.

Cyclospora does not spread person-to-person. Every infection traces to contaminated food or water. Cooking destroys the parasite; the risk is in raw or lightly handled fresh produce [3].

Michigan's geographic pattern

The Michigan Department of Health and Human Services has confirmed cases in seven counties: Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee, and Jackson [2]. This cluster — concentrated in southeastern Michigan — suggests a food source with a regional distribution footprint, though investigators have not yet confirmed one [1].

Michigan typically records approximately 50 cyclosporiasis cases per year [2]. More than 300 cases in 11 days represents a rate of accumulation that public health officials describe as "large and growing."

The source question

Past U.S. cyclospora outbreaks have repeatedly traced to imported fresh produce entering the supply chain from Mexico and Central America. Commonly implicated items have included cilantro, fresh basil, snow peas, raspberries, and mesclun lettuce [3]. The summer timing is consistent with peak cyclospora season.

As of Tuesday, no product has been recalled and no restaurant or grower has been identified. The investigation is active but slow, and public health workforce reductions documented by oversight bodies have constrained the number of investigators available [1].

The service task, stated plainly

If you ate fresh produce — particularly fresh herbs — within the past 14 days and have had diarrhea lasting more than a week, see a doctor and ask about cyclospora testing. The treatment is a course of trimethoprim-sulfamethoxazole; the infection does not resolve on its own [2]. If you are in Michigan and ate at a restaurant using fresh herbs between June 22 and July 7, your exposure window is consistent with the state's outbreak curve. A negative standard stool culture does not clear you — ask your physician specifically for cyclospora testing [2].

-- NORA WHITFIELD, Chicago