A Taylor Farms lettuce sample that initially tested positive for cyclospora has been determined to be a false positive, the Food and Drug Administration said Sunday.
The agency said its laboratory specialists took a second look at the results because detecting Cyclospora can be technically complex. After that review, the FDA concluded the sample “does not represent true amplification” and should be treated as a false positive.
In the same update, the FDA said that, as of Sunday, it had not identified any “confirmed positive sample results for product testing for Cyclospora.”
Taylor Farms said Friday it was “voluntarily removing” iceberg lettuce sourced from central Mexico after the product was linked to one of the largest cyclosporiasis outbreaks reported in the U.S. in recent years.
“While the FDA traceback is indicating a specific independent farm, which represents less than 1% of the U.S.’s iceberg lettuce supply, as the potential source of the outbreak, we have removed all iceberg lettuce from the region indefinitely,” the company said Friday in a statement.
Taylor Farms said Sunday in a statement after the false positive was announced that, “Our thoughts remain with everyone who has fallen ill in this outbreak. We are committed to working with public health authorities as the ongoing outbreak investigation continues.”
On Thursday, the U.S. Centers for Disease Control and Prevention identified lettuce supplied to select Taco Bell restaurants as a source in the multistate outbreak, more than a month after the first illnesses began to emerge.
According to the CDC, the iceberg lettuce was sent to Taco Bell locations in Indiana, Kentucky, Michigan, Ohio and West Virginia. Taco Bell said Friday that it had “completed removal of affected Taylor Farms lettuce from our restaurants.”
Walmart also said over the weekend that it had pulled four Marketside bagged iceberg lettuce salad products from stores in more than two dozen states, while noting there was “no indication that products sold in our stores are affected by the current Cyclospora investigations.”
The outbreak, first reported in May, has spread to 34 states and sickened more than 1,600 people, according to the CDC. However, the CDC’s tally lags behind state health departments, which have reported much larger numbers of cases. For instance, the Michigan Department of Health and Human Services reported more than 5,000 confirmed cases as of Friday.
No deaths have been reported.
Cyclosporiasis is a food- and waterborne illness caused by the cyclospora parasite, which causes long-lasting, watery and sometimes explosive diarrhea, according to public health experts.
Outbreaks typically occur in late spring and summer and have historically been linked to bagged salads, cilantro, basil, raspberries, snow peas and green onions.
Megan Cerullo
contributed to this report.
