Kroger is recalling ricotta salata cheese “affected in QFC stores” because it may be contaminated with Listeria monocytogenes. This is part of the larger recall of the Frescolina brand ricotta salata made by Forever cheese that has sickened at least 14 people in 11 states and killed two. The outbreak was announced by the CDC on September 11, 2012.
The cheese comes from one batch that was produced in Italy and imported to the United States. The FDA found the outbreak strain of the bacteria in an uncut sample of the cheese. Since the cheese can have a four-month shelf-life, and it was sold between June 20 and August 9, 2012, some customers may still have the cheese in their refrigerators. It’s possible that cross-contamination has occurred at some point along the distribution chain, which may have contaminated other cheeses and deli products.
Ricotta salata is a hard cheese made from sheep’s milk. It is not the same as ricotta cheese, which is a soft spreadable cheese usually used to make cheesecake and lasagna.
Cheese is often a vehicle for Listeria bacteria because it is is a low-acid, high moisture product. And Listeria bacteria are often prevalent in the creamery environment, especially when they are located on farms. The best way to eliminate Listeria in cheese is to sample the surfaces in the creamery, including walls, floors, work surfaces, and racks. Listeria encloses in a capsule, which makes it resistant to many sanitizers. And the bacteria can grow at refrigerator temperatures. Listeria is not heat-resistant, so when heating and cooking will destroy it.
Listeria also has a very long incubation period in humans. The symptoms of listeriosis may not manifest until 70 days after exposure. Someone who ate the contaminated cheese in July may not show symptoms until September or October. If you or anyone you know has eaten cheese and develops Listeria symptoms, which include flu-like fever, muscle aches, upset stomach, diarrhea, stiff neck, headache, loss of balance, and confusion, see your healthcare provider immediately and tell her you ate ricotta salata cheese.