CDC counts 17,180 U.S. cyclospora cases since May, most tied to Mexican iceberg lettuce

The Centers for Disease Control and Prevention's update dated 24 August put laboratory-confirmed cyclosporiasis acquired in the United States at 17,180 cases since 1 May. That compares with 1,180 cases between 1 May and 31 August 2025. Forty-eight states and the District of Columbia have reported at least one confirmed infection. New Mexico was the last state added to the map.

Nine hundred and twenty-two people have been hospitalised. Two have died. The median patient is 46. Ages run from 1 to 99. Fifty-six percent of cases are female. The median onset date is 7 July, with a range from 1 May to 19 August. The CDC is also holding 11,844 further reports that are not yet confirmed or not yet classed as domestically acquired.

The lettuce cluster

The largest single outbreak was traced to processed iceberg lettuce grown by Taylor Farms de Mexico and served in restaurants, including Taco Bell. As of 20 August that cluster covered 10,930 cases and 454 hospital stays in 17 states: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Massachusetts, Michigan, Missouri, Nebraska, New Hampshire, North Carolina, Ohio, Oklahoma, Pennsylvania and West Virginia. The recalled product is no longer on the market. Best-by dates have passed.

FDA is still investigating at least six other clusters whose sources are not settled. Four of seven outbreaks on the agency's tracker were still listed as ongoing in late August. CDC says it is unlikely that one vehicle explains the entire national total.

What the parasite does

Cyclospora cayetanensis is a protozoan. People swallow it on contaminated fresh produce. The illness is watery, often explosive diarrhoea, plus cramp, nausea and fatigue that can last weeks if untreated. It is not passed person to person in the way norovirus is. The seasonal pattern in the United States has always peaked in summer. This year's count is an order of magnitude above last year's summer window.

Michigan carried a large share of the iceberg cases. Two deaths there involved people with serious underlying illness. State officials said most Michigan onsets came before 16 July, which is why some epidemiologists now describe that cluster as past its peak even as the national confirmed total is still being revised upward. Reporting lag is real. A case counted in late August may have started in July.

For kitchens the practical instruction is ordinary and unsatisfying. Wash produce. Cook when you can. The recalled iceberg is gone. The six open clusters mean other items may still be named. Until those traceback files close, the safer reading of the CDC table is that summer 2026 produced the largest documented cyclospora season in the United States, and that one lettuce line explains most, not all, of it.