Health officials are monitoring an increase in cyclosporiasis, a foodborne illness caused by the Cyclospora parasite, after more than 1,200 cases were reported in Michigan and infections were identified in at least 17 states, according to ABC News and the Centers for Disease Control and Prevention.
Cyclosporiasis typically spreads when people consume food or water contaminated with the parasite. It is not generally transmitted from person to person. In the United States, past outbreaks have often been linked to fresh produce, including lettuce, basil, cilantro, bagged salad mixes and raspberries. Officials have not identified a specific food source in the multistate reports.
Symptoms usually appear about one week after exposure, though onset can range from two days to two weeks. Common symptoms include nausea, bloating, abdominal cramping and watery diarrhea. Unlike many gastrointestinal infections, which often resolve within several days, cyclosporiasis-related diarrhea can continue for weeks or months without treatment. Medical evaluation is recommended for diarrhea lasting more than three days. Treatment commonly involves a 10-day course of antibiotics.
While anyone can become infected, some groups face higher risks of complications, especially dehydration. These include children, older adults, pregnant people, individuals with chronic medical conditions and people receiving chemotherapy or living with weakened immune systems.
Cases are more common from May through August. The parasite develops readily in warm, humid conditions, and summer eating patterns often include increased consumption of produce, including imported fruits and vegetables.
Public health guidance emphasizes prevention measures: wash hands for at least 20 seconds before preparing or eating food and after using the bathroom; wash and scrub produce under running water; and refrigerate produce promptly after purchase.
As of July 2025, cyclosporiasis is no longer required reporting under the CDC’s Foodborne Diseases Active Surveillance Network, although cases may still be reported to state health departments.