Listeriosis is a foodborne illness caused by Listeria monocytogenes, bacteria found in soil and water. It can be in a variety of raw foods as well as in processed foods and foods made from unpasteurized milk. Listeria is unlike many other germs because it can grow even in the cold temperature of the refrigerator.
Symptoms include fever and chills, headache, upset stomach and vomiting. Treatment is with antibiotics.
Anyone can get the illness. But it is most likely to affect pregnant women and unborn babies, older adults, and people with weak immune systems. To reduce your risk
Centers for Disease Control and Prevention