FDA closes investigation into Cyclospora outbreak linked to iceberg lettuce

(WWAY) — The Food and Drug Administration has closed its investigation into a multistate Cyclospora outbreak linked to recalled iceberg lettuce from Mexico.

The FDA announced Friday that its investigation into infections linked to iceberg lettuce sourced from central Mexico and recalled by Taylor Farms de Mexico has concluded. The Centers for Disease Control and Prevention previously declared the outbreak over Sept. 11.

The FDA says it is confident all recalled iceberg lettuce connected to the outbreak is now off the market.

As part of its investigation, the FDA traced the lettuce to several farms and a processing facility in Mexico that supplied recalled lettuce distributed by Taylor Fresh Foods.

Investigators conducted inspections and collected samples of water, soil, sediment and iceberg lettuce at multiple growers and the processing facility.

Two environmental samples tested positive for Cyclospora, according to the FDA.

One came from a tank holding outgoing wastewater at the Taylor Farms de Mexico processing facility. The other was collected from a drainage ditch at an iceberg lettuce grower identified during the investigation.

The FDA said there is not enough evidence to conclusively determine how the contamination occurred. However, the positive samples showed Cyclospora was present in the environment where the lettuce was grown and processed and provided additional evidence supporting the connection between the outbreak and the recalled shredded iceberg lettuce.

Genotyping of the two positive environmental samples has been completed, and the FDA is continuing to analyze how those results relate to genotyping of clinical specimens.

The FDA says it will continue working with federal, state and international partners on post-outbreak activities and prevention efforts ahead of the 2027 growing season.