(LEGAFI) -- True Leaf Farms of Salinas, California, has expanded a romaine lettuce recall from 90 cartons to nearly 2,500 cartons after federal investigators discovered the product could be potentially contaminated with Listeria – the germ responsible for killing dozens of people who consumed tainted cantaloupe in one of the deadliest food outbreaks in a decade.

True Leaf initially announced a recall of 90 cartons of romaine lettuce shipped to an Oregon food service distributor, which shipped the produce to Washington and Idaho. However, a chief executive for the company that markets and sells the farm’s produce clarified that the romaine lettuce recall actually involved 2,500 cartons. Only 90 cartons went to retail sales, while 2,500 cartons were mostly sold to restaurants, cafeterias and other institutions in 19 states and Canada. 

The True Leaf recall affects nearly 33,000 pounds of romaine lettuce. It was issued after federal officials found that a sample from one bag tested positive for Listeria. Listeria rarely shows up in produce, but 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. 

While most healthy adults can consume Listeria without becoming ill, it can kill the elderly and those with compromised immune systems. It is also dangerous to pregnant women because it easily passes through to the fetus. 

Symptoms of Listeria include fever and muscle aches, often with other gastrointestinal symptoms. Victims often become incapacitated and unable to speak.

No illnesses have been reported in connection to the True Leaf recall.

The True Leaf lettuce recall covers products with a “use by date” of September 19 and a bag and box code of B256-46438-8.

The states covered by the True Leaf lettuce recall include Alaska, Alabama, Arizona, California, Colorado, Connecticut, Florida, Illinois, Kentucky, Maryland, Minnesota, Missouri, Nevada, New York, Ohio, Oregon, Pennsylvania, Tennessee and Vermont.