Listeria Infection


Listeria infection, a serious foodborne illness caused by bacteria, poses a significant risk to pregnant women, individuals over 65, and those with weakened immune systems, primarily through consumption of improperly processed deli meats and unpasteurized milk products. While healthy individuals seldom fall ill from this infection, it can be fatal for unborn babies, newborns, and the immunocompromised. The resilience of listeria bacteria, capable of surviving refrigeration and freezing, necessitates that those at higher risk of serious infections steer clear of foods most likely to harbor these bacteria. Prompt antibiotic treatment can mitigate the effects of listeria infection, highlighting the importance of vigilance and preventive measures.


Symptoms of listeria infection may manifest a few days after consuming contaminated food, with the incubation period potentially extending to 30 days or more.

  • Initial symptoms: First signs of infection include nausea, diarrhea, chills, muscle pain, and high temperature, or fever.
  • Neurological system: Signs and symptoms that the listeria infection may have progressed to the neurological system include headache, tight neck, confusion or shifts in attentiveness, dizziness, and seizures.
  • In newborn: Newborns with listeria infection may display subtle signs such as feeding disinterest, irritability, fever, vomiting, and breathing issues.
  • During pregnancy: Mothers may experience mild symptoms, but the consequences for the baby can be grave, ranging from intrauterine death to life-threatening infections shortly after birth.

If any of the signs and symptoms occur after consuming food recalled due to a listeria outbreak or suspected contamination, consult a healthcare provider for proper diagnosis and treatment.

In case of a high fever, severe headache, stiff neck, confusion, or sensitivity to light, seek emergency care as these may signal bacterial meningitis, a serious complication of listeria infection. Generally, be vigilant for signs of illness like fever, muscle aches, nausea, or diarrhea.


Listeria infection can result from consuming raw vegetables contaminated with soil or manure, tainted meat, unpasteurized milk or its products, and certain processed foods such as soft cheeses, hot dogs, and deli meats that might become contaminated after processing. Listeria bacteria, found in soil, water, and animal feces, can pose significant health risks to humans when ingested through various contaminated sources.

Risk factors

Although anyone can get a listeria infection, certain people are more prone to having it, such as:

  • Individuals with weakened immune systems: This vulnerable category faces an increased risk of infections and complications due to their compromised immune responses. This include people who:
    • Prescribed with drugs to prevent organ transplant rejection
    • Taking high-dose prednisone or specific rheumatoid arthritis medications
    • Aged over 65
    • Have acquired immunodeficiency syndrome (AIDS)
    • Recipients of chemotherapy
    • Has diabetes or kidney disease
  • Pregnant women: The consequences may include a life-threatening infection in baby, miscarriage, stillbirth, or premature birth. Generally, pregnant women exhibit a higher susceptibility to listeria infections compared to other healthy adults.