Listeria infection is a foodborne bacterial illness that can be very serious for pregnant women and people with impaired immune systems. Listeria infection is most commonly contracted by eating improperly processed deli meats and unpasteurized milk products.
Healthy people rarely become ill from listeria infection, but the disease can be fatal to unborn babies and newborns. People who have weakened immune systems also are at higher risk of life-threatening complications. Prompt antibiotic treatment can help curb the effects of listeria infection.
Listeria bacteria can survive refrigeration and even freezing. That's why people who are at higher risk of serious infections should avoid eating the types of food most likely to contain listeria bacteria.