Listeria: A group of bacteria capable of causing illness including potentially fatal infections in the elderly, newborns, pregnant women, and persons with a weakened immune system. Listeria monocytogenes is the form of Listeria most commonly responsible for infections.
Symptoms of listeriosis include fever, muscle aches, nausea and diarrhea. If infection spreads to the nervous system, symptoms such as headache, stiff neck, confusion, loss of balance, or convulsions can occur. Infection during pregnancy may appear mild but can lead to stillbirth, premature delivery and infection of the newborn.
Listeria contamination has been responsible for numerous recalls of food. Listeria infection may be spread through different methods including direct contact with infected lesions, food-borne transmission, and passage from mother to fetus in pregnancy or to the infant during birth.
Persons at risk can prevent the infection by avoiding certain high-risk foods and by handling food properly. You should thoroughly cook raw food from animal sources (such as beef, pork, or poultry), keep uncooked meats separate from vegetables, cooked foods and ready-to-eat foods, wash raw vegetables thoroughly before eating them, and avoid raw (unpasteurized) milk or foods made from raw milk.
Listeria are named after the English surgeon and apostle of antisepsis, Joseph Lister (1827-1912). Disease caused by Listeria bacteria is called listeriosis.
REFERENCE: Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.