The U.S. Food and Drug Administration has made a reversal in one of the country's largest recent foodborne illness investigations, acknowledging that a laboratory test that appeared to detect the Cyclospora parasite in shredded iceberg lettuce was actually a false positive.
Despite the reversal, the agency says its investigation still points to shredded iceberg lettuce supplied by Taylor Farms de Mexico as the source of a multistate cyclosporiasis outbreak that has sickened more than 1,600 people.
