Transmission: The bacterium is found in soil and water. Vegetables can become contaminated from the soil or from manure used as fertilizer for the vegetables.

Animals may carry the bacteria without appearing sick, creating infected meat and dairy products.

People get listeriosis by eating food contaminated with the bacteria. Babies may be born with the disease if their mothers ate contaminate food during pregnancy.

Symptoms: A variety of symptoms may be present, including fever, difficulty breathing, vomiting, general tiredness, and irritability. Diarrhea is the most commonly reported symptom. Listeria infection may lead to pneumonia, meningitis or sepsis, which is an infection of the blood.

Prevention: Thoroughly cook raw food from animal sources. Thoroughly wash all vegetables before eating. Do not drink unpasteurized milk. Wash hands after handling raw meat, as well as all cutting boards, knives, etc. Eat perishable and ready-to-eat foods as soon as possible.

Pregnant women should be especially careful with food preparation and what they eat.

There have been documented cases of listeriosis being transmitted through a variety of foods: cold cuts, soft-ripened cheese, milk, undercooked chicken, uncooked hot dogs, shellfish, and coleslaw made from contaminated cabbage.