If you develop a listeria infection, you might have: 
Fever
Chills
Muscle aches
Nausea
Diarrhea
 Symptoms might begin a few days after you've eaten contaminated food, but it can take 30 days or more before the first signs and symptoms of infection begin. If the listeria infection spreads to your nervous system, signs and symptoms can include: 
Headache
Stiff neck
Confusion or changes in alertness
Loss of balance
Convulsions
 Symptoms during pregnancy and in newborns During pregnancy, a listeria infection is likely to cause only mild signs and symptoms in the mother. The consequences for the baby, however, can be devastating — the baby can die in the womb or have a life-threatening infection within a few days of being born. Signs and symptoms of a listeria infection in a newborn can be subtle, but can include: 
Little interest in feeding
Irritability
Fever
Vomiting
Difficulty breathing
