Listeria infection
DEFINITION
Listeria infection is a foodborne bacterial illness that can be very serious for pregnant women and people with impaired immune systems. Listeria infection is most commonly contracted by eating improperly processed deli meats and unpasteurized milk products.
Healthy people rarely become ill from listeria infection, but the disease can be fatal to unborn babies and newborns. People who have weakened immune systems also are at higher risk of life-threatening complications. Prompt antibiotic treatment can help curb the effects of listeria infection.
Listeria bacteria can survive refrigeration and even freezing. That’s why people who are at higher risk of serious infections should avoid eating the types of food most likely to contain listeria bacteria.
CAUSES
Listeria bacteria can be found in soil, water and animal feces. Humans typically are infected by consuming:
- Raw vegetables that have been contaminated from the soil or from contaminated manure used as fertilizer
- Infected animal meat
- Unpasteurized milk or foods made with unpasteurized milk
- Certain processed foods — such as soft cheeses, hot dogs and deli meats that have been contaminated after processing
- Unborn babies can contract a listeria infection from the mother via the placenta.
SYMPTOMS
If you develop a listeria infection, you may experience:
- Fever
- Muscle aches
- Nausea
- Diarrhea
Symptoms may begin a few days after you’ve eaten contaminated food, but it may take as long as two months before the first signs and symptoms of infection begin.
If the listeria infection spreads to your nervous system, signs and symptoms may include:
- Headache
- Stiff neck
- Confusion or changes in alertness
- Loss of balance
- Convulsions
- Symptoms during pregnancy and for newborns
During pregnancy, a listeria infection is likely to cause only mild signs and symptoms in the mother. The consequences for the baby, however, may be devastating. The baby may die unexpectedly before birth or experience a life-threatening infection within the first few days after birth.
As in adults, the signs and symptoms of a listeria infection in a newborn can be subtle, but may include:
- Little interest in feeding
- Irritability
- Fever
- Vomiting
When to see a doctor
- If you’ve eaten a food that’s been recalled because of a listeria outbreak, pay close attention to any possible signs or symptoms of illness. If you experience fever, muscle aches, nausea or diarrhea, contact your doctor. The same goes for illness after eating a potentially contaminated product, such as foods made with unpasteurized milk or poorly heated hot dogs or deli meats.
- If you experience a high fever, severe headache, stiff neck, confusion or sensitivity to light, seek emergency care. These signs and symptoms may indicate bacterial meningitis, a life-threatening complication of a listeria infection.
