Listeria Infection

What is Listeria Infection?

A listeria infection, or listeriosis, occurs when a person eats food contaminated with the bacterium listeria monocytogenes especially foods like unpasteurized milk products and improperly processed meats. Although some people can get over a listeria infection without treatment, high-risk people can have complications, like meningitis, endocarditis, and encephalitis. High-risk people include women who are pregnant, people with weak immune systems, those with cancer, those with AIDS, alcoholics, diabetics, the elderly, and newborns.

What are the Symptoms of Listeria Infection?

Diarrhea is a common sign of listeriosis, as well as vomiting, nausea, fever, a stiff neck, headaches, confusion, and the loss of balance.

In high-risk persons and those with comprised immune systems, the development of complications like meningitis and septicemia and more serious symptoms, like seizures, can occur. Pregnant women may feel flu-like symptoms, and in worse cases, can have a miscarriage, premature delivery, stillbirth, or infected newborn.

Listeria Infection Causes

A listeria infection is caused by listeria monocytogenes, a bacterium with a rod shape. It is commonly found in many areas and is present in soil, in decaying plants and in the water. It is a common bacterium among domestic animals, wild animals, and livestock. Even if an animal isn’t showing symptoms of the infection, it can still pass along the bacteria to humans. This contamination is often passed along in the food that is made with the infected animals. It can also come from meat and dairy products that contaminate surfaces such as drains, floors, and tables.

Most cases of listeria infection in humans come from food that is contaminated with this bacteria. It can contaminate pre-packaged foods as well as raw vegetables, uncooked meat, soft cheeses, smoked seafood and milk and dairy products that have not been pasteurized. In babies, the infection can be passed along from the mother during pregnancy or during the delivery. Most people who are infected with listeria are those who are unhealthy or have a compromised immune system. This can include the elderly, newborns, cancer patients, pregnant women, those who are HIV positive, diabetics and people with kidney disease.

How is Listeria Infection Treated?

If a person has a mild case of listeriosis, then he or she does not need treatment and can let the infection run its course. However, high-risk persons should seek medical attention right away. For instance, pregnant women can often prevent an infection in the fetus if they have a doctor prescribe antibiotics. Newborns can also receive antibiotics for a listeria infection.

Listeria Infection Prevention

The easiest way to prevent a listeria infection is to be careful about what you eat. This isn’t guaranteed to prevent an infection, but washing food thoroughly before consuming it can reduce your chance of being infected with listeria. Wash your hands after handling food as well as after handling animals. Learn safe food-handling practices such as keeping raw meat away from other foods such as fruits and vegetables. When cooking raw foods, be sure to cook them thoroughly to kill any bacteria they may harbor. Keep food-preparation areas clean and sanitized to avoid contaminating other foods. Keep fluids from raw meats from coming into contact with any surfaces.

Last Reviewed:
October 06, 2016
Last Updated:
June 02, 2018