Michigan health officials said nearly 700 cyclosporiasis cases had been confirmed in the state as of July 6, with 678 of them concentrated in southeast Michigan, including Wayne County, while Ohio reported 177 cases as of July 2. The numbers show an outbreak that is still climbing in more than one state, and one that is hitting Michigan far harder than usual.
People are searching for cyclosporiasis now because the counts were updated this week and the illness can move quietly before it is recognized. In Michigan, the confirmed total is about 13.5 times the state's usual annual count of 50 cases, a jump that has put the outbreak well beyond routine summer surveillance. In Ohio, most of the 177 cases — 171 — were reported since June 20, and cases have already been confirmed across 43 counties.
Dr. Natasha Bagdasarian said the illness has a long lag between exposure and symptoms, which makes it harder for investigators to see the outbreak as it spreads. She said there is a significant delay between contact with contaminated produce or other contaminated material and the start of illness, and that symptoms can appear a week later, sometimes two weeks later. That helps explain why new cases can keep surfacing even after officials start warning the public.
Cyclosporiasis spreads through food or water contaminated with feces, and foodborne outbreaks have been linked to imported fresh produce such as raspberries, basil, snow peas, mesclun lettuce and cilantro. The most common symptom is explosive watery diarrhea, though cramping, bloating, low-grade fever, nausea and vomiting can also occur. Some patients never feel sick at all, which makes the outbreak harder to track by symptoms alone.
The part health officials have not yet solved is whether Michigan has a common source. Cases are rising quickly, but investigators still have not identified a shared produce item or distribution link in the state. That leaves the outbreak in a familiar but uneasy place: the case count is already large, the illness can keep appearing for days after exposure, and the source may still be sitting in the food chain.
The Centers for Disease Control and Prevention had already reported 145 cases in 17 states, excluding Michigan, as of June 16, with at least 20 people hospitalized and no deaths reported. Taken together, the figures suggest a multistate outbreak that is still expanding while officials try to match illness patterns with a source that may have passed through imported produce before anyone noticed.
