Key facts
- The U.S. CDC has linked four additional states to a multistate cyclosporiasis outbreak.
- Illinois, Kansas, Oklahoma, and Pennsylvania are the newly added states.
- The outbreak is traced to shredded iceberg lettuce from central Mexico.
- Michigan investigators are focusing on lettuce and salad greens as potential sources.
- The CDC has reported over 1,600 confirmed cases and 141 hospitalizations nationally as of mid-July.
- The CDC's national tally of cases has surpassed 4,000, exceeding the total for the previous year.
The U.S. Centers for Disease Control and Prevention (CDC) has linked four additional states—Illinois, Kansas, Oklahoma, and Pennsylvania—to a multistate outbreak of cyclosporiasis, according to a Washington Post report citing sources familiar with the investigation. These states join Indiana, Kentucky, Michigan, Ohio, and West Virginia in the outbreak, which has been traced to shredded iceberg lettuce sourced from central Mexico.
Michigan public health investigators have indicated that lettuce and other salad greens are being examined as potential sources of the illness. As of July 13, the CDC reported 1,645 laboratory-confirmed cases and 141 hospitalizations nationally. More recently, the CDC significantly updated its national tally, adding over 4,000 confirmed illnesses and noting that domestic cases this year have already surpassed the total reported in 2025.
Cyclosporiasis is a gastrointestinal illness caused by a microscopic parasite. Symptoms include diarrhea, abdominal cramps, bloating, loss of appetite, weight loss, fatigue, nausea, low-grade fever, and vomiting. Public health officials are conducting detailed interviews, analyzing stool specimens, and performing trace-back investigations with state and local health departments and the FDA to identify the common source. While historically linked to international travel, outbreaks have increasingly been associated with domestic and imported produce.