December 22 21:17 2019 Print This Article

Listeriosis is an infection caused by Listeria monocytogenes bacteria. It can be a serious disease. The most common source of infection is contaminated food such as deli meats, unpasteurized milk or dairy products, soft cheeses, and paté. Despite being so widespread, most infections in humans result from eating contaminated foods. Listeriosis has recently been recognized as an important public health problem in the United States.

Infection is rare, but when it does occur it most frequently affects pregnant women in their last trimester, newborns, and children and adults whose immunity is weakened by diseases such as cancer or AIDS.In the United States, an estimated 1,850 persons become seriously ill with listeriosis each year. While many bacteria generally infect specific locations within the human body, Listeria may infect many different sites, such as the brain or spinal cord membranes or the bloodstream.

Listeria monocytogenes is a Gram-positive rod-shaped bacterium.Most people are not at increased risk for listeriosis. However, there are some people who are considered at risk because they are more susceptible to listeriosis. Animals and people can carry Listeria in their bodies without becoming sick. The disease affects primarily pregnant women, newborns, and adults with weakened immune systems.

Once infected, Listeria lives in the gastrointestinal tract.. In direct smears they may be coccoid, so they can be mistaken for streptococci. Longer cells may resemble corynebacteria. The true incidence of listeriosis in humans is not known, because in the average healthy adult, infections are usually asymptomatic, or at most produce a mild influenza-like disease. Most people are not at increased risk for listeriosis. However, there are some people who are considered “at risk” because they are more susceptible to listeriosis.

Causes of Listeria monocytogenes

The comman causes of Listeria monocytogenes include the following:

  • Listeriosis is caused by infection with the germ Listeria monocytogenes, which is found in the soil and in most animals.
  • Animals can carry the bacteria and can contaminate meats and dairy products.
  • Listeria bacteria can be transmitted through soil and water.
  • Unpasteurized (raw) milk or foods made from unpasteurized milk can be contaminated.
  • A number of strains of bacteria can cause acute bacterial meningitis.
  • The primary method of person-to-person transmission is neonatal infection in utero (through the placenta) or during passage through an infected birth canal.
  • Vegetables can become contaminated from the soil or from manure used as fertilizer.

Symptoms of Listeria monocytogenes

Some sign and symptoms related to Listeria monocytogenes are as follows:

  • Fulminant illness in the newborn causing death within a few hours of birth.
  • Fatigue.
  • High fever.
  • Loss of appetite.
  • Vomiting.
  • Headache.
  • Signs of meningeal irritation.
  • Poor feeding.
  • Increased pressure inside the skull (due to meningitis) may cause the skull’s “sutures” to become separated.
  • Lethargy.
  • Jaundice.
  • Occasionally abdominal pain.
  • Nausea.
  • Stillbirth is also a sign of Listeria monocytogenes.

Treatment of Listeria monocytogenes

Here is list of the methods for treating Listeria monocytogenes:

  • Listeriosis is usually treated with antibiotics (penicillin or erythromycin) administered in the hospital through an intravenous catheter (IV).
  • Trimethoprim-sulfamethoxazole is used as an alternative therapy.
  • Foreign food products such as nonpasteurized soft cheeses have also been implicated in outbreaks of listeriosis. Food should always be adequately cooked.
  • Pregnant women require prompt, vigorous treatment to combat fetal infection.
  • Babies with listeriosis receive the sameantibiotics as adults, although a combination of antibiotics isoften used until physicians are certain of the diagnosis.
  • Pregnant women should avoid consumption of soft cheeses, deli meats, and cold salads from salad bars.