The Food and Drug Administration says a lettuce sample that prompted a recall by Taylor Farms did not actually test positive for cyclospora.

The agency says a review of the laboratory results found the original positive test was a false positive, and there are currently no confirmed product samples testing positive for the parasite.

Taylor Farms says the FDA apologized for the error, but the company is keeping its voluntary recall of iceberg lettuce in place while the investigation continues.

The CDC says nearly 7,000 cases of cyclosporiasis have been confirmed or are under investigation nationwide since May. The illness can cause severe diarrhea, fatigue, and loss of appetite.