Listeriosis is a type of foodborne illness. It is caused by Listeria monocytogenes bacteria. This kind of bacteria is found in soil and water. You can get infected by eating uncooked vegetables and meats, unpasteurized dairy products, and processed foods such as cold cuts. The risk of serious illness is highest for pregnant women, newborns, and people who have weak immune systems.

In pregnant women, the infection can cause problems. These problems may include miscarriage, premature birth, or stillbirth. Babies can be born with the infection if their mothers eat contaminated food during pregnancy. Antibiotics can often prevent infection of the fetus or newborn.

Symptoms include fever, muscle aches, and sometimes nausea or diarrhea. In some cases, symptoms such as headache, stiff neck, and confusion can occur. Pregnant women may have only mild, flu-like symptoms.