A parasitic infection caused by the Cyclospora parasite is spreading across the United States, with the US Centers for Disease Control and Prevention (CDC) confirming 1,645 cases and investigating 5,100 possible cases across 34 states as of July 15, 2026. The infection causes diarrhoea, nausea, and other gastrointestinal symptoms.

Cyclosporiasis, the intestinal infection caused by Cyclospora, is contracted by consuming contaminated food such as raw fruits and vegetables or water contaminated with faeces. Symptoms can range from mild to severe, with children, older adults, and immunocompromised individuals at higher risk of serious illness. While rarely life-threatening, untreated infections can last for weeks and may lead to hospitalisation due to dehydration.

The CDC reported that sick individuals began showing symptoms on or after June 22 in four main states: Michigan, Ohio, West Virginia, and Kentucky. Michigan typically records 40 to 50 cases annually. As of July 13, New York, Illinois, Kentucky, New Jersey, North Carolina, and Texas have each reported 31 or more cases.

Officials are conducting traceback investigations by collecting data on foods consumed by infected individuals to trace the outbreak back through the supply chain, potentially to the farm level. The CDC notes that cases usually rise between May 1 and August 31.

Sporadic cases in Australia are generally linked to travellers' diarrhoea.

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