• By Deb Balzer

Infectious Diseases A-Z: Prevent listeria infection

June 19, 2017

Public health officials are encouraging consumers to take steps to reduce their risk of listeria infection after recent outbreaks of the foodborne illness.

Watch: Dr. Nipunie Rajapakse explains listeria infection.

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"Listeria is a type of bacteria that can be found in food products, and can cause quite serious foodborne illness in certain populations," says Dr. Nipunie Rajapakse, a Mayo Clinic infectious diseases specialist. "We worry about it especially in pregnant women and their newborns, people who have weakened immune systems, and in the elderly."

Dr. Rajapakse says the most common foods that listeria infection is associated with are usually deli meats, hot dogs, and products that are refrigerated for a prolonged period of time. "Listeria is one of the few bacteria that likes to divide at low temperatures. That’s why we see this being a problem in foods that are refrigerated."

Symptoms of listeria infection include:

  • Fever
  • Muscle aches
  • Nausea
  • Diarrhea

But Dr. Rajapakse adds, "Listeria infection can present in different ways in different people. In newborns, it can present as what we call sepsis, or a systemic infection, or bloodstream infection. This can make newborn infants sleepy or lethargic. It can cause brain infections, blood infections, and make them quite sick overall. In other populations, such as pregnant women, or elderly or immunocompromised patients, the most worrisome form of listeria infection is meningitis, or infection around the surface of the brain. However, it can also cause bloodstream infections in those populations, as well."

Simple food safety precautions, such as good hand hygiene, scrubbing raw fruits and vegetables, and ensuring food is thoroughly cooked, can help prevent infection.

Women who are pregnant, and those with a weak immune system should take these precautions to avoid listeria infection:

  • Do not eat soft cheeses, unless it's clear from the packaging that the product was made using pasteurized milk.
  • Avoid hot dogs, luncheon meats and deli meats, unless they're reheated until steaming hot. Keep fluid from hot dog packages away from other foods, utensils and food preparation surfaces. Wash your hands after handling hot dogs, luncheon meats or deli meats.
  • Don't eat refrigerated pates or meat spreads. Canned or shelf-stable pates and meat spreads are acceptable.
  • Don't eat refrigerated smoked seafood. Such products may be labeled as nova style, lox, kippered or jerky. One exception is if you're using these products in a casserole or other cooked dish. Canned or shelf-stable smoked seafood products are acceptable.