US Cyclosporiasis Cases Surge During 2026 Season

The CDC reported 15,716 laboratory-confirmed cases of cyclosporiasis acquired in the United States from May 1 through August 17, 2026. For comparison, 1,180 cases were reported in the United States from May 1 through August 31, 2025.

Among the 2026 US-acquired cases, 828 patients were hospitalized, and 2 died. Cases were reported by 47 states, the District of Columbia, and Puerto Rico. Patients ranged from 1 to 99 years of age, with a median age of 46 years; 57% were female. The median illness onset date was July 7, 2026, with dates ranging from May 1 through August 13.

The CDC is investigating multiple clusters, including a large multistate outbreak linked to processed iceberg lettuce from central Mexico. The agency said this outbreak contributed significantly to the increase in cases this year. The CDC and FDA are also investigating at least 6 other clusters for which sources have not been confirmed.

At least 11,841 additional cases are either not laboratory confirmed or require further investigation to determine whether they were acquired in the United States. The CDC said it is working with states to update surveillance data as more cases are confirmed. The agency characterized the data as preliminary and subject to change, and noted that state totals may be higher because they can include cases that do not meet CDC reporting criteria.

Separately, the CDC reported 1,681 laboratory-confirmed cases acquired outside the United States from May 1 through August 17, including 61 hospitalizations and no deaths. The agency asks healthcare providers to report cyclosporiasis cases to local health departments according to local practices. The CDC monitors laboratory-confirmed cases year-round with state and federal health and regulatory officials to identify outbreaks potentially linked to a common food source.

Source: CDC. Surveillance of cyclosporiasis. Updated August 18, 2026. Accessed August 19, 2026.