In the nation’s largest outbreak of cyclosporiasis, the CDC has reported 4,940 lab-confirmed and 341 hospitalizations across 41 states, according to a July 21 update.
Between May 1 and July 20, the federal health agency reported 4,173 domestic cases and 767 illnesses acquired outside the U.S. A majority of hospitalizations, 308, are also domestically linked.
In 2025, the U.S. recorded 3,955 cyclosporiasis cases, meaning the number of illnesses over the past 11 weeks have exceeded last year’s total, according to the Washington Post.
The FDA and CDC’s traceback investigations have “converged” on now-recalled iceberg lettuce grown in Mexico by Taylor Farms, one of the largest fresh-produce suppliers for the U.S. Despite a false positive test, federal officials seem to have traced a significant portion of the outbreak to Taylor Farms.
Normally, cyclosporiasis cases annually peak between May 1 and Aug. 31. This year, a spike of illnesses had a June 26 onset date, according to the CDC. Michigan and surrounding states appear to be hardest-hit, with Michigan officials reporting 6,571 cases and 102 hospitalizations as of July 21, and Ohio logging 1,246 confirmed cases as of July 16.
State counts typically surpass CDC figures since the federal agency only reports lab-confirmed cases, while state health departments might report confirmed and suspected counts. The CDC said July 20 it “is aware of more than 7,400 additional cases that are not yet laboratory confirmed and require further investigation and analysis,” particularly in Michigan and Ohio.
“We assume a 6-week reporting lag between illness onset and case reporting to CDC, so we anticipate that case counts will continue to rise as data are received,” the agency said.
Cyclosporiasis is a nationally notifiable disease in 47 states, plus New York City and Washington, D.C. The nine states that have not reported cases to the CDC are Delaware, Hawaii, Maine, Montana, New Mexico, Oregon, South Carolina, South Dakota and Vermont.
Some hospitals in the hardest-hit states have altered food offerings from cafeterias during the outbreak, and testing labs have strained to keep pace. Some medical supplies could face shortages, including tools needed for molecular panel tests and antibiotics indicated for cyclosporiasis.
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