Clinical syndromes associated with Listeria infection include febrile gastroenteritis, sepsis, meningitis, encephalitis, and infections causing spontaneous abortions, stillbirth, and neonatal disease.

Listeria infections have been reported from California to Virginia, the Centers for Disease Control and Prevention (CDC) said in an update.

Listeria infections can cause miscarriages and stillbirths among pregnant women.

Although healthy individuals may suffer only short-term symptoms such as high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea, Listeria infections can cause miscarriages and stillbirths among pregnant women.

Listeria infections are acquired primarily through the consumption of contaminated foods, including soft cheese, raw milk, deli salads, and ready-to-eat foods such as luncheon meats and frankfurters.

Better understanding the cell biology of Listeria infections, including relevant virulence factors, may lead to better treatments for listeriosis and other intracytoplasmic parasite infections.

Listeria infections must be treated with injectable antibiotics - penicillin, ampicillin or gentamicin - or intravenous trimethoprim/sulfamethoxazole.

The report also stated that further deaths were being investigated to determine if they had also been caused by Listeria infection.

Listeria infections can cause pregnant women to miscarry; the first miscarriage attributed to the 2011 outbreak was reported in early October, in a woman living in Iowa.

The FDA made the public announcement for the recall after Listeria infection was confirmed by Jensen Farms at its main Colorado branch.