Listeria—full name Listeria monocytogenes—is a species of harmful bacteria that can cause digestive discomfort and even serious illness if ingested. It thrives in moist environments and can be found in soil, water and animal droppings, making improperly washed/prepared foods a common source of listeria outbreaks and infections. Some infections are mild; others can be lethal.
Hardy bacteria, listeria can survive high temperatures, refrigeration and even freezing. So if you suspect contamination, throw out any possibly tainted food and carefully sanitize all surfaces with disinfectant.
What Foods Are At Risk For Listeria Contamination?
All food has the potential to be contaminated with listeria bacteria, but certain foods do pose more risk.
Foods most commonly associated with listeria infection include:
- Raw fruits and vegetables contaminated from soil or manure
- Unpasteurized milk or foods made with unpasteurized milk, such as certain cheeses
- Ice cream
- Raw or smoked fish/seafood
- Raw or undercooked poultry
- Hot dogs, deli meats and other processed foods subject to cross-contamination
How To Prevent Listeria Infection
While food and safety regulations keep most harmful bacteria like listeria out of our food, there are some common sense preventative measures you can follow to protect against listeria infection.
- Thoroughly wash all fruits and vegetables before eating
- Cook poultry to its proper internal temperature
- Exercise caution or avoidance with unpasteurized products and raw foods
- Always heat deli meat until its steaming hot
- Check expiration dates before eating
- Refrigerate properly
- Avoid or consume ready-to-eat products promptly
Symptoms of Listeria Infection
The symptoms of listeria infection will vary depending on the health of the individual and the extent of the infection. People with compromised immune systems, people over 65, babies and small children, and people who are pregnant are at higher risk for serious symptoms.
Mild symptoms typically indicate that the listeria infection is contained to the intestines and digestive system, and include:
- Diarrhea
- Nausea & Vomiting
- Fever
- Muscles aches
But if the listeria infection worsens and spreads to the nervous system, more serious symptoms may include:
- Headache
- Stiff Neck
- Confusion
- Loss of Balance
- Convulsions
If you experience any of these symptoms, seek emergency care immediately. For those at highest risk, a listeria infection can even be fatal.
Pregnancy & Listeria Infection
While a listeria infection may only cause mild symptoms for the mother, it presents a serious risk to the pregnancy, and can often lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn. If a pregnant person suspects possible listeria ingestion or infection, seek treatment immediately.
Treatment for Listeria Infection
If you believe you have eaten food contaminated with listeria, watch for symptoms. If any develop, contact your healthcare provider.
Mild cases of listeria infection may need no treatment at all, aside from over-the-counter medications for symptom management, but it’s best to be safe and let your doctor make that call. For more serious cases, your healthcare provider can prescribe antibiotics to cure the infection.
If you are in one of the high-risk categories—babies, the elderly, pregnant women, people with compromised immune systems—your healthcare provider may recommend antibiotics for mild symptoms, to prevent the infection from becoming more serious in the first place.
If you develop high fever, headache, or neurological symptoms, such as confusion, loss of balance or light sensitivity, seek emergency care immediately.
To recover effectively remember:
- Take all medications as directed by your healthcare provider
- Get plenty of rest
- Drink lots of fluids
- Eat what you can but eat light
Written by Sarasota Memorial copywriter Philip Lederer, MA, who crafts a variety of external communications for the healthcare system. SMH’s in-house wordsmith, Lederer earned his Master’s degree in Public Administration and Political Philosophy from Morehead State University, KY, and should eat more (well-washed) fruits and vegetables.