What Happens If You Get Listeria?

Listeria (listeriosis) is a potentially serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. Symptoms include nausea and vomiting, among others. It is usually not serious in otherwise healthy people.

Listeria (listeriosis) is a potentially serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. 

In otherwise healthy people, Listeria is usually not serious but it can be dangerous in pregnant women. A pregnant woman can also pass Listeria to the unborn baby, who can have severe illness and even die.

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
• Headache
• Nausea and vomiting
• Stiff neck
• Confusion or trouble thinking
• Weak muscles on one side of the body, trouble walking, or shaky hands
• Seizures 

Symptoms of Listeria infection in the bloodstream include:

• Fever
• Chills
• Dizziness
• Low blood pressure
• Fast heart rate
• Pain in joints and muscles

Symptoms of Listeria infection in the digestive system include:

• Fever
• Watery diarrhea
• Nausea and vomiting
• 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

Listeria infection (listeriosis) is most often 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.

People at higher risk of getting very sick from Listeria include:

• Newborns
• Older people
• People with compromised immune systems, such as people who have AIDS, cancer, an organ transplant or stem cell transplant, or who take immunosuppressive medications 
• People who have diabetes or another serious medical condition

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

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.

Complications of Listeria (listeriosis) include: 

• Severe infection (sepsis)
• Meningitis
• Encephalitis
• Brain abscess
• Endocarditis
• Gastroenteritis 
• Pregnancy complications
  • Miscarriage
  • Stillbirth
  • Premature delivery
  • Life-threatening infection of the newborn
• Death in severe cases

Listeria (listeriosis) infection may be prevented by following food safety guidelines, such as:

• Do not consume unpasteurized milk and cheese or foods made with them
• Thoroughly wash produce before eating 
• Keep the refrigerator colder than 40° F (4.4° C) and the freezer below 0° F (-18° C)
• Cook meat and seafood until well done
• Cook eggs until the yolk is firm
• Wash hands, knives, and cutting boards after contact with raw food

Pregnant women and people with weakened immune systems should avoid foods such as:

• Raw milk
• Soft cheeses 
• Hot dogs
• Deli meats
• Refrigerated pâtés or meat spreads
• Smoked seafood (such as lox)