CDC Confirms Over 18,000 Domestic Cyclospora Cases Since May
Since May 1, 2026, 18,445 laboratory-confirmed cyclosporiasis cases acquired in the U.S. have been reported. The CDC is investigating multiple clusters, including a large multistate outbreak linked to processed iceberg lettuce from central Mexico. An additional 3,491 cases are under review to determine if they were domestically acquired or travel-related.
The current season's domestic case count of 18,445 represents a dramatic surge compared to the 1,180 cases reported during the same window in 2025. The CDC attributes much of this increase to a large multistate outbreak traced to processed iceberg lettuce from central Mexico, though additional clusters remain under investigation with sources not yet confirmed.
Among confirmed domestic cases, 990 hospitalizations and two deaths have been recorded across 49 states and the District of Columbia. The median patient age is 46, with a slight female majority. An additional 3,491 cases await determination of domestic versus travel origin, and roughly 13,505 more reports are pending laboratory confirmation or patient interviews. Because symptom onset to reporting can take about six weeks, the CDC expects case counts to keep rising beyond the official season's end.
This outbreak could strain public health resources and consumer confidence in fresh produce, particularly imported lettuce. The sharp year-over-year increase may prompt heightened scrutiny of food supply chains and processing practices. Vulnerable populations, including older adults and immunocompromised individuals, may face the greatest risk of severe outcomes. The investigation's outcome could influence future import regulations and industry standards, while affected communities may experience economic ripple effects from reduced produce sales.