Cyclosporiasis Outbreak Accelerates: Record Case Rates Surge Across Five States

Cyclosporiasis outbreak spikes in the Midwest

Between May 1 and July 20 the CDC confirmed ↑ 4,173 cases of the diarrheal parasite, already surpassing the ↓ 4,000 reported for all of 2025.

Cases have been logged in at least 41 states, but five states now carry the official outbreak designation, with Michigan leading the pack at an estimated 15 per 100,000 residents, based on CDC mid‑range counts and 2025 Census data.

“Contaminated iceberg lettuce remains the most likely vector,” a CDC spokesperson told Reuters.

Ohio, Indiana, Kentucky and West Virginia follow, reporting infection rates of roughly 3.3, 3.3, 2.6 and 1.2 per 10,000 people respectively. The agency estimates an additional 7,400 probable cases—many untested—still pending laboratory confirmation.

Public health officials stress that while sporadic cases are routine, the clustering this year signals a breach in the food supply chain that could widen if mitigation efforts lag behind the disease’s incubation period.

Correction: An earlier dispatch misstated the July 20 cut‑off date as July 30.

Analysis by Elena Rostova (Socio-Economic Trends Analyst).