A sample of lettuce from Taylor Farms that initially tested positive for cyclospora has been deemed a false positive by the FDA, the agency announced Sunday.

The FDA re-reviewed the sample results and concluded that the finding was not a true amplification, resulting in the false positive designation. Taylor Farms had voluntarily removed iceberg lettuce sourced from central Mexico after the initial positive test.

Cyclospora Outbreak Update

The outbreak, which has spread to 34 states and sickened over 1,600 people, is believed to have originated from lettuce supplied to select Taco Bell restaurants. The CDC identified the source of the multistate outbreak on Thursday, with cases first reported in May.

Taylor Farms has stated that it will continue to work with public health authorities as the investigation continues. The company had removed all iceberg lettuce from the region indefinitely, despite the FDA indicating that the potential source of the outbreak represented less than 1% of the US’s iceberg lettuce supply.

Walmart also removed four Marketside bagged iceberg lettuce salad products from its stores in over two dozen states as a precautionary measure. However, the company noted that there was no indication that its products were affected by the current cyclospora investigations.

Investigation and Implications

The CDC’s tally of cases lags behind state health departments, with some states reporting much larger numbers of confirmed cases. The Michigan Department of Health and Human Services reported over 5,000 confirmed cases as of Friday.

The cyclospora outbreak highlights the importance of food safety and the need for continued investigation into the source of the contamination. As the investigation continues, the FDA and CDC will work to determine the root cause of the outbreak and prevent future cases.

The broader significance of this outbreak lies in its impact on the food supply chain and the need for increased vigilance in ensuring the safety of produce, particularly during peak summer months when cyclosporiasis cases typically rise.