What is listeriosis?

Listeriosis is food poisoning caused by eating foods contaminated with the Listeria monocytogenes (L. monocytogenes) bacterium. In pregnant women, the infection can result in miscarriage, premature delivery, serious infection of the newborn, or even stillbirth.

Listeriosis affects mainly pregnant women, newborns, the elderly, and adults with impaired immune systems. Healthy adults and children sometimes are infected with L. monocytogenes, but they rarely become seriously ill. Babies can be born with listeriosis if their mothers eat contaminated food during pregnancy.

The symptoms of listeriosis include fever, muscle aches, and sometimes nausea or diarrhea. If infection spreads to the nervous system, symptoms such as headache, stiff neck, confusion, loss of balance, or convulsions can occur.

Listeriosis is diagnosed based on a medical history and physical exam. Your doctor will ask you questions about your symptoms, foods you have recently eaten, and your work and home environments. A blood test or spinal fluid test may be done to confirm the diagnosis.

If you are pregnant and get listeriosis, antibiotics can often prevent infection of the fetus or newborn. Babies who have listeriosis receive the same antibiotics as adults, although a combination of antibiotics is often used until your doctor is certain the cause is listeriosis.

An otherwise healthy person who is not pregnant typically does not need treatment. Symptoms will usually go away within a few weeks.