Listeriosis (Listeria monocytogenes Infection)

Listeria Summary
Listeria is a type of bacteria that can cause food poisoning. Listeriosis symptoms include diarrhea, nausea and fever. Pregnant women are 20 times more likely than other healthy adults to get listeriosis. Listeria infection is treated with antibiotics.
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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.
  • Most people who are infected have few or no symptoms; when symptoms are present, they usually consist of fever, muscle aches, nausea, or diarrhea. Some people may develop more severe symptoms such as meningitis, mental changes, brain abscesses, or death.
  • 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) 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.
  • 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.

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Listeria Sources, Intubation Period, Duration, Risks

Sources of Listeria

  • Ready-to-eat deli meats and hot dogs
  • Refrigerated pâtés or meat spreads
  • Unpasteurized (raw) milk and dairy products
  • Soft cheese made with unpasteurized milk, such as queso fresco, Feta, Brie, Camembert
  • Refrigerated smoked seafood
  • Raw sprouts

The incubation period for Listeria infection is 3-70 days.

Symptoms of Listeria infection include:

  • Fever, stiff neck, confusion, weakness, vomiting, sometimes preceded by diarrhea

The duration of illness from Listeria infection can be days to weeks.

Who's at Risk for Listeria Infection?

  • Older adults
  • Pregnant women
  • People with weakened immune systems
  • Organ transplant patients who are receiving drugs to prevent the body from rejecting the organ

People with certain diseases, such as:

  • HIV/AIDS or other autoimmune diseases
  • Cancer
  • End-stage renal disease
  • Liver disease
  • Alcoholism
  • Diabetes

SOURCE: Listeria.