A California food company has recalled some 30,000 pounds of lettuce feared tainted by listeria. The lettuce was distributed in 19 states and Canada, reports the Wall Street Journal. So far no illness linked to the lettuce has been reported, but 16 people have died from listeria in Colorado cantaloupe. Most of the chopped romaine lettuce sold by True Leaf Farms of San Juan Bautista was sold to food-service companies and likely ended up in restaurants and cafeterias. Random tests discovered listeria in a batch of the lettuce, and True Leaf voluntarily recalled all 90 cartons shipped to an Oregon distributor, reports AP. Officials are seeking the source of the contamination.