The Food and Drug Administration said on Saturday ​a sample of shredded iceberg lettuce supplied by ‌Taylor Farms has tested positive for a parasitic illness that has sickened thousands of people in the U.S.

Taylor Farms has confirmed ​that this product is not part of ​its current recall, the FDA said in the statement ⁠as it seeks to curtail the largest foodborne illness ​outbreak in the United States in recent years.

The California-based ​lettuce supplier is working to identify whether any part of the sample that tested positive is available in commerce or ​in consumers’ homes, the FDA said in its most ​recent update.

Earlier in the day, the supplier posted a list of ‌lettuce ⁠products that had been recalled following investigations that it was a potential source of contamination.

Taylor Farms was not immediately available for comment.

The FDA said the sample ​was collected during ​targeted surveillance ⁠while investigating the ongoing outbreak and that the positive lot has been detained.

Cyclosporiasis ​which has been linked to shredded iceberg lettuce ​served ⁠at Yum Brands , Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio and West Virginia has so far resulted in ⁠around ​100 hospitalizations and no deaths, ​according to the Centers for Disease Control and Prevention.