Cyclospora outbreak surges across U.S. with Michigan reporting over 1,200 cases
A parasite that causes severe, persistent diarrhea is sickening unusually high numbers of people across the United States this summer, with Michigan emerging as the hardest-hit state.
The outbreak in numbers
At least 531 cyclospora infections had been confirmed nationwide by early July, according to the CDC, already four times the number reported at the same point last year. The toll is likely far higher: state-level data show a rapid escalation, particularly in Michigan. On Wednesday, July 8, health officials there reported 992 cases, a nearly 500 percent increase from the previous week. By Thursday, July 9, the count had jumped to 1,251, a 26 percent single-day rise. Other states, including New York, Ohio and Illinois, are also seeing higher-than-usual totals. Pennsylvania’s case count reached 28 on Thursday, with half of those in the southeast, though Philadelphia itself has not exceeded its baseline.
- CDC reports 145 cases across 17 states (May 1–June 16)
- Michigan reports 992 cases, a 500% weekly increase
- Michigan cases rise to 1,251; Pennsylvania confirms 28 cases
Expert concern
Dr. Moore, an infectious disease specialist at the University of Kansas School of Medicine–Wichita, said the trend is alarming but noted that cyclospora infections rarely cause serious complications. Keith R. Schneider, a food safety professor at the University of Florida, called the Michigan numbers a “huge spike” and added,This spike in illness is definitely abnormal.
Something is going on right now in that area.
The parasite and its symptoms
Cyclospora cayetanensis is a microscopic parasite that infects people when they consume food or water contaminated with human feces containing the parasite’s oocysts. There is no direct person-to-person transmission. The hallmark symptom is watery, sometimes explosive diarrhea, often accompanied by abdominal cramping, nausea, fatigue and loss of appetite. Symptoms can persist for days to over a month if untreated. Dr. Carlos del Río of Emory University noted that the diarrhea’s persistence is key:
Treatment usually involves antibiotics, although some infections resolve without them.A diarrhea that does not recover quickly tends not to go away until treated.
How to stay safe
Health officials recommend washing all produce under running water, scrubbing firm items like cucumbers with a clean brush, and cutting away bruised or damaged areas. Because cyclospora often spreads through fresh produce such as cilantro, basil, lettuce and berries, thorough washing is the primary defense. Cooking kills the parasite.
Investigation underway
The CDC does not yet know the source of the outbreak, and acting Parasitic Disease Branch chief Dianna Blau said there are probably multiple contamination sources. The investigation remains active as case counts continue to climb across multiple states.
