Taylor Farms Cyclospora Outbreak: FDA Finds Parasite at Mexico Facility and Grower Drainage Ditch

The US Food and Drug Administration (FDA) has detected Cyclospora in two environmental samples at sites linked to a major iceberg lettuce outbreak that sickened 12,883 people across 21 states, but investigators have not established how the parasite contaminated the produce.

The agency announced the findings on Friday, 2 October, as it closed its investigation into the outbreak, which resulted in 570 hospitalisations and two deaths. The US Centers for Disease Control and Prevention (CDC) declared the outbreak over on 11 September, with the last reported illness onset on 17 August.

One positive sample came from a tank holding outgoing wastewater at the Taylor Farms de Mexico processing facility in central Mexico. The other was collected from sediment in a drainage ditch at an iceberg lettuce grower identified during the FDA's traceback investigation.

FDA Findings Do Not Establish Contamination Route

The environmental findings add evidence to the investigation linking the outbreak to shredded iceberg lettuce supplied by Taylor Farms de Mexico. However, the FDA said it could not conclusively determine the root cause of contamination at the locations involved in growing and processing the lettuce.

The agency completed genotyping of the two positive environmental samples and was continuing to analyse how the results compared with samples from people who became ill. The findings do not, on their own, establish how the parasite reached the lettuce or prove a specific route of contamination.

The outbreak investigation followed epidemiological and traceback evidence linking illnesses to the recalled lettuce. The CDC reported 12,883 illnesses across 21 states, at least 570 hospitalisations and two deaths in Michigan.

The CDC said the outbreak had ended and the recalled products were no longer available in stores or restaurants. It also noted that reported case totals can continue to reflect the timing of illness reporting and testing.

Recall Began in July

Taylor Farms de Mexico announced a voluntary recall of iceberg lettuce sourced from central Mexico on 17 July. The FDA published the company's recall notice on 18 July, identifying the possible risk of Cyclospora contamination.

The recall covered iceberg lettuce products distributed to food-service customers and certain retail outlets, including products sold under multiple brand names. The company said it was removing the affected lettuce from the US market because of the potential contamination risk.

The recall preceded the FDA's announcement of the two positive environmental samples by more than two months. The later findings should therefore not be described as the trigger for the July recall.

The FDA also corrected an earlier positive border-sample result after determining that the test had been a false positive. That correction was separate from the environmental sampling reported on 2 October.

Company Says Facility Remains Closed

Taylor Farms said its central Mexico facility remained closed while it worked with research specialists to implement enhanced food-safety protocols. The company also attributed the contamination identified by the FDA to an independent grower that it said was no longer part of its supplier programme.

Those statements represent the company's account of its response. The FDA's public findings do not establish the precise route by which the lettuce became contaminated.

Mexican authorities reported that their own testing did not detect Cyclospora in the lettuce and water samples they examined during their investigation. Those results differ from the FDA's later environmental findings, which came from a wastewater tank and drainage-ditch sediment. The different results concern the samples collected and tested; they do not establish that either agency's samples were identical.

FDA Sets Out Prevention Measures for 2027

Alongside the investigation's closure, the FDA announced ten planned activities intended to reduce the risk of future Cyclospora outbreaks before the 2027 growing season.

The measures include increased surveillance of commodities associated with the parasite, outreach to growers on practices intended to reduce contamination risks, and updates to the agency's prevention, response and research plan. The FDA also intends to publish an outbreak investigation report summarising its findings and recommendations.

The agency's investigation has identified positive environmental samples at sites connected through traceback to the implicated lettuce, but the precise contamination mechanism remains unresolved. Its planned prevention work will focus on improving surveillance, supporting safer growing practices and strengthening responses to future outbreaks.