A California farm said Thursday it was voluntarily recalling bags of chopped romainelettuce because of possible contamination with listeria, though no illnesses have been reported.
True Leaf Farms of Salinas announced the recall of 90 cartons that were shipped to an Oregon food service distributor. From the distributor, it might have gone to at least two other states, Washington and Idaho.
The Food and Drug Administration notified the company that a sample from one bag taken as part of a random check tested positive for listeria.
Federal health officials say they've gotten better at detecting the germs that cause food poisoning, so they are seeing them in produce more often.
The lettuce recall covers product with a use by date of Sept. 29. The bag and box code is B256-46438-8.
California health officials are looking into the contamination, said Ken August, spokesman for the California Department of Public Health, but have not yet determined how the lettuce became contaminated.
"Anytime there is a contaminated food product, we are concerned and take steps so that it's removed from shelves as quickly as possible and to notify consumers," he said.
Listeria rarely shows up in produce, but an outbreak linked to cantaloupe from a Colorado farm has caused at least 72 illnesses, including up to 16 deaths, in 18 states.
August said the state is working with the company to verify the distribution of the produce being recalled. Most of the lettuce was sold to California institutions such as restaurants and cafeterias, he said, and only a small amount went to retail in other states, August said.
The Salinas Valley is known as the "Salad Bowl of the World" for its production of lettuce and numerous other crops.
Lettuce currently picked at the farm is safe to eat, said Steve Church, CEO of Church Brothers, which sells and markets the farm's produce. The company is working with the FDA, Church said, to determine if there are any problems at the farm and is taking more time to sanitize its produce.