What Are the First Signs of Listeria?

Symptoms of Listeria can come on suddenly and some of the first signs of Listeria may include fever, muscle aches, severe headache, nausea, vomiting, stiff neck, confusion, loss of balance, and convulsions. Listeria may also cause serious complications in pregnant women.

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 woman can also pass Listeria to the unborn baby, who can have severe illness and even die.

The first symptoms and signs of Listeria (listeriosis) can start within a few days after eating contaminated food, but the incubation period for Listeria can be long and symptoms may develop one month or more after ingestion. 

Symptoms of Listeria can come on suddenly and some of the first signs of Listeria may include: 

• Fever
• Muscle aches
• Severe headache 
• Nausea
• Vomiting
• Stiff neck
• Confusion
• Loss of balance
• Convulsions

Symptoms of Listeria may vary depending on which part of the body is affected.

In addition to signs and symptoms above, symptoms of Listeria infection in the brain and spinal cord include:

• Weak muscles on one side of the body
• Trouble walking
• Shaky hands

Additional symptoms of Listeria infection in the bloodstream may include:

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

Additional symptoms of Listeria infection in the digestive system may include:

• Watery diarrhea
• Pain in joints and muscles

In pregnant women, symptoms of Listeria infection may include:

• Miscarriage
• Stillbirth
• Premature delivery
• Life-threatening infection of the newborn