An illness caused by infection with bacteria and spread through contaminated food.

Listeriosis is caused by bacteria found in soil, water and animal stool. The bacteria spread to people through contaminated raw vegetables, meat, milk or foods made with contaminated milk. People with weakened immune systems are most at risk.

Symptoms show up a few days to 30 days after contact with the bacteria. Fever and chills, muscle aches, feeling sick to the stomach, or loose stools are symptoms.

Medicines that target bacteria, called antibiotics, treat serious listeriosis illness or listeriosis that happens during pregnancy. Milder illness may need treatment only to manage symptoms.