The first documented case of Lysteria was in 1926.

There are 10 species of the Lysteria genus. L. fleischmannii, L. grayi, L. innocua, L. ivanovii, L. marthii, L. monocytogenes, L. rocourtiae, L. seeligeri, L. weihenstephanensis and L. welshimeri.

Listeria can be found in soil, which can lead to vegetable contamination.

Animals can also be carriers of Lysteria.

Listeria has been found in uncooked meats, uncooked vegetables, fruit such as cantaloupes and apples, pasteurized or unpasteurized milk, foods made from milk, and processed foods.