Listeriosis is a dangerous infection caused by eating food contaminated with bacteria called Listeria monocytogenes (L. monocytogenes).

According to the U.S. Centers for Disease Control and Prevention, listeriosis is an important public health problem in the United States.

The bacteria (L. monocytogenes) that cause this disease are common in wild animals, domesticated animals, and in soil and water. The bacteria make many animals sick and commonly lead to miscarriage and stillbirth in domestic animals.

Vegetables, meats, and other foods you eat can get infected with the bacteria if they come in contact with contaminated soil or manure. Raw milk or products made from raw milk may carry these bacteria.

If you eat the contaminated products, you may get sick. Pregnant women, developing fetuses, newborns, and adults with weakened immune systems are at increased risk. The bacteria most often cause a gastrointestinal illness. In some cases, you can develop a blood infection (septicemia) or inflammation of the covering of the brain (meningitis).

Infection in early pregnancy generally leads to miscarriage. The bacteria may cross the placenta and infect the developing baby. Infections in late pregnancy may lead to stillbirth or death of the infant within a few hours of birth. About half of infants infected at or near term will die.