Parasite Causing Severe Diarrhoea Spreads Across 34 US States

By the Editorial Team · Thursday, July 16, 2026

The CDC has confirmed over 1,600 cases of cyclosporiasis across 34 states, with thousands more suspected, as health officials investigate a widespread outbreak linked potentially to a fast-food chain. Identifying the exact source is critical to controlling the spread, and authorities urge symptomatic individuals to seek medical care while continuing their investigation.

A parasite responsible for causing severe diarrhoea has infected thousands of individuals across 34 states in the United States, according to the Centers for Disease Control and Prevention (CDC). As of late Tuesday, the federal health agency reported more than 1,600 confirmed cases of cyclosporiasis, with an additional 5,100 suspected cases currently under investigation.

Cyclosporiasis, caused by the parasite Cyclospora cayetanensis, often presents with gastrointestinal symptoms including watery diarrhoea, cramping, and nausea. The CDC has cautioned that the actual number of infections is likely higher than reported, given that many cases remain undiagnosed or unreported.

The outbreak has prompted an ongoing investigation to determine potential sources of the infections. Preliminary reports have indicated that the fast-food chain Taco Bell may be linked to the spread of the parasite, though the CDC has not confirmed this association and continues to gather evidence.

State and federal health officials are working to identify common food items or points of exposure to contain the spread and provide guidance on prevention. The CDC advises individuals experiencing prolonged diarrhoea or related symptoms to seek medical attention and follow recommended hygiene practices to reduce transmission.

The investigation remains active, with authorities urging those who have consumed food from suspected sources or who have symptoms consistent with cyclosporiasis to report to healthcare providers. Further updates are expected as additional data become available and the source(s) of the outbreak are clarified.

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