National cyclosporiasis outbreak source remains unidentified

US Centers for Disease Control and Prevention (CDC) announced there is a large multistate outbreak of cyclosporiasis occurring in at least 4 midwestern states. Public health officials are interviewing people linked to this outbreak to find out what foods they ate before getting sick.

Symptoms of cyclosporiasis typical begin appearing a week after exposure and include watery diarrhea, nausea, loss of appetite, abdominal pain, fatigue and weight loss. It is a gastrointestinal illness caused by the microscopic parasite Cyclospora.

As of July 13, 2026, more than 400 people infected with Cyclospora have been reported to CDC from 4 states in connection with this multistate outbreak: Michigan, Ohio, West Virginia, and Kentucky. CDC is aware of additional cases that are still under investigation. Sick people reported symptoms on or after June 22, 2026.

No specific food item has yet been confirmed as the source. Investigators are collecting as much information to locate the source of this outbreak.

The following map shows where the 1,645 people with cyclosporiasis acquired in the United States since May 1, 2026, lived. Cyclosporiasis cases may not be limited to states with known cases. The true number of people sick with cyclosporiasis was likely higher than the number reported. This is because some people recover without medical care and are not tested for Cyclospora.

State map indicating confirmed Cyclosporas cases as of July 13, 2026. Source: US Centers for Disease Control and Prevention (CDC)

Officials with the Washington State Department of Health advise washing your hands when preparing, cooking and eating produce. Washing produce will not destroy the Cyclospora parasite, only cooking will do that.

Persons at increased risk of illness should avoid these items until the source has been identified.