U.S. Cyclospora Outbreak Has Become Largest on Record

Public health authorities are investigating a significant spike in cases across 34 states linked to food safety concerns.

Updated on Oct. 1, 2026 in Organic Food

Bold flat-color editorial illustration of a single lettuce leaf, symbolizing the investigation into a national food safety outbreak. — The U.S. has recorded its largest-ever Cyclospora outbreak, with 1,645 confirmed cases across 34 states prompting intense investigations into the food supply chain. AI Illustration. Upload story photo >

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The United States is currently facing the largest recorded Cyclospora outbreak in history, with 1,645 confirmed cases reported since May 1, 2026. Health officials are also reviewing an additional 5,100 potential cases across 34 states.

Why it matters

The outbreak has led to 141 hospitalizations, prompting increased scrutiny on food supply chains and safety protocols. Investigators are working to identify a specific source, as no individual grower, processor, or brand has been linked to the illnesses.

Active CDC surveillance has identified 1,645 confirmed domestically acquired cases of Cyclospora, with 141 hospitalizations reported. A total of 34 states have reported cases, though the exact origin of the outbreak remains under investigation.

The players

CDC

The national public health agency responsible for monitoring infectious disease outbreaks and tracking foodborne illnesses.

International Fresh Produce Association

A trade organization representing the global fruit and vegetable industry, focused on food safety standards and supply chain health.

LGMA

A safety-focused consortium that monitors lettuce growing and production standards to ensure product quality.

The details

Cyclospora is a microscopic parasite that typically causes intestinal illness when ingested through contaminated food or water. While investigators have identified lettuce as a common food item among patients, no specific product has been confirmed as the vector. The International Fresh Produce Association is currently calling for enhanced collaboration between the industry and public health authorities to pinpoint the source.

Confirmed cases began accumulating on May 1, 2026.
Michigan and the LGMA released statements regarding the outbreak on September 28, 2026.

Health Landscape

This outbreak represents a historic escalation in the domestic incidence of Cyclospora infections. It surpasses previous events in both scope and the number of states reporting sustained transmission.

If you experience prolonged intestinal symptoms, consult your physician to discuss potential testing for foodborne parasites. Awareness of food safety during this active investigation is prudent, though no specific products have been recalled.

The takeaway

This outbreak remains active and under investigation by health authorities across the country. Monitor official reports from the CDC for updates and discuss any persistent gastrointestinal symptoms with your primary care provider.