Listeriosis (Listeria monocytogenes Infection)

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Listeriosis (Listeria monocytogenes infection) facts

  • Listeriosis is a disease caused by a gram-positive bacterium named Listeria that can penetrate and replicate inside human cells.
  • Symptoms of listeriosis are variable; most people who are infected have few or no symptoms; when symptoms of Listeria infection are present, they usually consist of
  • Some people may develop more severe symptoms such as
  • Death may occur.
  • Although most people have self-limited disease, people with risk factors such as an altered or depressed immune response (for example, pregnant females and their fetus or newborn, cancer patients, AIDS patients, people with diabetes, and alcoholics) are at higher risk for getting the disease and some are more likely to have more severe disease.
  • Listeriosis is usually diagnosed by discovering that a person was associated with an outbreak of Listeria-contaminated food or fluid or identified as a person associated with the source of a known listeriosis outbreak. Definitive diagnosis is done when Listeria bacteria are isolated from the patient's blood, cerebrospinal fluid, or other body fluid.
  • Most normal people spontaneously clear the infection and require no treatment. In contrast, people with risk factors should be treated quickly with IV antibiotics.
  • People are exposed to Listeria bacteria if they ingest contaminated food or fluid. Foods that are not cooked or fluids that are not treated or pasteurized are frequently the sources of infection. Pregnant females can transmit Listeria organisms to their fetus or to their newborn. In general, listeriosis is not contagious from person to person (except in pregnancy); the disease is transmitted to humans mainly by contaminated food or fluids.
  • Cooking foods, treating or pasteurizing fluids, and avoiding food and fluids that may be contaminated with animal or human waste may prevent infection.
  • The prognosis for most Listeria infections is excellent even if people have consumed contaminated foods or fluid; however, the prognosis rapidly declines in patients with risk factors if they are not quickly diagnosed and treated.
  • U.S. government agencies are responsible for maintaining safe foods and fluids for the U.S. population and may enforce regulations to ensure contaminated products are reported, removed, recalled, and production and sales stopped until processing meets acceptable standards of safety.
Medically Reviewed by a Doctor on 4/10/2015

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Food poisoning

Listeriosis Symptoms, Signs, and Diagnosis

What are Listeria infection symptoms and signs?

In most people, Listeria infection symptoms and signs mainly include the common symptoms of food poisoning such as

  • fever,
  • nausea and vomiting,
  • diarrhea,
  • abdominal pain and cramping,
  • back pain.

If Listeria causes more severe illness, patients may also experience

  • headache,
  • dizziness,
  • pain in joints and muscles,
  • confusion,
  • stiff neck,
  • seizures.