CDC Investigates Cyclosporiasis Outbreak Across 17 States

The Centers for Disease Control and Prevention (CDC) is actively investigating the source of a cyclosporiasis outbreak that is spreading across the United States. The outbreak has affected at least 145 individuals in 17 states, with approximately 20 people hospitalized due to severe symptoms.

Health officials have identified several clusters of cases, particularly in New York, Illinois, and Texas. According to data from the CDC as of May 1, 2026, New York has experienced the most significant impact, with 31 to 80 individuals affected. Other states involved include Alaska, Colorado, Connecticut, Florida, Georgia, Louisiana, Massachusetts, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, and Wisconsin.

Cyclosporiasis is a foodborne illness caused by a parasite. This condition typically results from consuming food or water that has been contaminated. While cyclosporiasis is usually not life-threatening, it can produce severe symptoms such as cramps, nausea, fatigue, and vomiting. Most notably, the CDC reports instances of “watery diarrhea with frequent, sometimes explosive, bowel movements.” The illness can persist for a few days to over a month without antibiotic treatment and may cause symptoms to reappear sporadically.

The affected individuals range in age from 5 to 86 years, with the average age being 42. Although the parasite is more common in tropical or subtropical regions, only 45 of the patients had traveled outside the U.S. prior to falling ill. This has led health officials to suspect a foodborne source, although the specific origin remains unidentified.