CDC Investigates Growing Cyclosporiasis Outbreak in 17 States

The Centers for Disease Control and Prevention (CDC) is investigating a spreading parasitic illness across the United States. To date, at least 145 cases of cyclosporiasis have emerged in 17 states, with 20 individuals hospitalized due to severe symptoms.

Public health teams are actively examining clusters in New York, Illinois, and Texas. The CDC’s map, current as of May 1, 2026, outlines the cyclosporiasis cases. In New York, 31 to 80 cases have been documented, marking it as one of the most affected areas.

Additional states impacted by the outbreak are Alaska, Colorado, Connecticut, Florida, Georgia, Louisiana, Massachusetts, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, and Wisconsin.

Understanding Cyclosporiasis

The CDC identifies cyclosporiasis as a type of food poisoning caused by the Cyclospora parasite. Infection occurs through the consumption of contaminated food or water. Though not typically life-threatening, the illness presents with severe symptoms such as cramps, nausea, fatigue, and vomiting.

The illness is notably marked by watery diarrhea, sometimes leading to explosive bowel movements. Without antibiotic treatment, symptoms can linger from several days to over a month, with potential recurrence.

Risk Factors and Investigation

The ages of those affected range from 5 to 86, averaging 42 years old. A heightened risk of cyclosporiasis is associated with residing in or traveling to tropical or subtropical regions where the parasite flourishes. However, only 45 people in this outbreak had traveled outside the U.S., prompting health officials to suspect a domestic foodborne source, though the precise cause remains unidentified.