Listeria (listeriosis) is a potentially serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes.
In healthy people, Listeria is usually not serious but it can be dangerous in pregnant women. Pregnant women can also pass Listeria to the unborn baby, who can have severe illness and even die.
23 Foods with Listeria Risk
Pregnant women and people with weakened immune systems should avoid foods that may have a high risk of containing Listeria such as:
- Raw (unpasteurized) milk or foods that contain unpasteurized milk
- Soft and semi-soft cheeses
- Feta
- Brie
- Camembert
- Blue-veined cheeses
- Queso blanco
- Queso fresco
- Panela
- Hot dogs
- Deli meats
- Ready-to-eat meals
- Foods at ready-to-eat salad bars, sandwich bars, and delicatessens
- Refrigerated pâtés or meat spreads
- Refrigerated smoked seafood (often labeled lox, nova-style, kippered, smoked, or jerky)
- Salmon
- Trout
- Whitefish
- Cod
- Tuna
- Mackerel
- Unwashed raw fruits and vegetables (such as sprouts)
- Soft-serve ice cream
- Raw shellfish and seafood
What Are Symptoms of Listeria?
Symptoms of Listeria (listeriosis) vary depending on which part of the body is affected.
Symptoms of Listeria infection in the brain and spinal cord include:
- Fever
- Nausea
- Vomiting
- Headache
- Stiff neck
- Confusion or trouble thinking
- Weak muscles on one side of the body
- Trouble walking
- Shaky hands
- Seizures
Symptoms of Listeria infection in the bloodstream include:
- Fever
- Chills
- Low blood pressure
- Fast heart rate
- Dizziness
- Pain in joints and muscles
Symptoms of Listeria infection in the digestive system include:
- Fever
- Nausea and vomiting
- Watery diarrhea
- Headache
- Pain in joints and muscles
In pregnant women, symptoms of Listeria infection may include:
- Miscarriage
- Stillbirth
- Premature delivery
- Life-threatening infection of the newborn
What Causes Listeria?
Listeria infection (listeriosis) is usually caused by eating food contaminated with Listeria monocytogenes bacteria.
If Listeria infection occurs during pregnancy, the bacteria can spread to the baby through the placenta.
How Is Listeria Diagnosed?
Tests to diagnose Listeria (listeriosis) include:
- Blood tests
- Lumbar puncture (spinal tap)
- Stool tests
- Imaging tests of the brain
- Magnetic resonance imaging (MRI)
- Computerized tomography (CT) scan
What Is the Treatment for Listeria?
Healthy people with Listeria infection (listeriosis) don’t usually need treatment and the illness goes away in about 2 days.
Pregnant women, newborns, and people with serious infections are treated with antibiotics.
From 
https://www.uptodate.com/contents/listeria-the-basics?search=Listeria&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
https://bestpractice.bmj.com/topics/en-gb/914
https://www.cdc.gov/listeria/index.html
https://www.pregnancybirthbaby.org.au/listeria-food-poisoning
https://www.fda.gov/food/health-educators/listeria-food-safety-moms-be