Listeriosis

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Listeriosis
Classification and external resources
ICD-10 A32.
ICD-9 027.0
DiseasesDB 7503
MedlinePlus 001380
eMedicine med/1312  ped/1319

Listeriosis is a bacterial infection caused by a gram-positive, motile bacterium, Listeria monocytogenes.[1] Listeriosis is relatively rare and occurs primarily in newborn infants, elderly patients, and patients who are immunocompromised.[2]

In veterinary medicine, however, listeriosis can be a quite common condition in some farm outbreaks. It can also be found in wild animals. See : "listeriosis in animals".

Contents

[edit] Epidemiology

Incidence in 2004–2005 was 2.5–3 cases per million population and year in the USA, where pregnant women accounted for 30% of all cases.[3] Of all nonperinatal infections, 70% occur in immunocompromised patients. Incidence in the USA has been falling since the 1990s, in contrast to Europe where changes in eating habits have lead to an increase during the same time. In Sweden, it has stabilized at around 5 cases per annum and million population, with pregnant women typically accounting for 1–2 of some 40 total yearly cases. [4]

[edit] Pathogenesis

Listeria monocytogenes is ubiquitous in the environment. The main route of acquisition of Listeria is through the ingestion of contaminated food products. Listeria has been isolated from raw meat, dairy products, vegetables, and seafood. Soft cheeses, unpasteurized milk and unpasteurised pâté are potential dangers, however post-pasteurization outbreaks of infection from dairy have been from pasteurized milk.[1]

There are four distinct clinical syndromes:

  • Infection in pregnancy: Listeria can proliferate asymptomatically in the vagina and uterus. If the mother becomes symptomatic, it is usually in the third trimester. Symptoms include fever, myalgias, arthralgias and headache. Abortion, stillbirth and preterm labor are complications of this infection.
  • Neonatal infection (granulomatosis infantisepticum): There are two forms. One, an early-onset sepsis, with Listeria acquired in utero, results in premature birth. Listeria can be isolated in the placenta, blood, meconium, nose, ears, and throat. Another, late-onset meningitis is acquired through vaginal transmission, although it also has been reported with caesarean deliveries.
  • CNS infection: Listeria has a predilection for the brain parenchyma, especially the brain stem, and the meninges. It can cause cranial nerve palsies, encephalitis, meningitis, meningoencephalitis and abscesses. Mental status changes are common. Seizures occur in at least 25% of patients.
  • Gastroenteritis: L monocytogenes can produce food-borne diarrheal disease, which typically is noninvasive. The median incubation period is 1-2 days, with diarrhea lasting anywhere from 1-3 days. Patients present with fever, muscle aches, gastrointestinal nausea or diarrhea, headache, stiff neck, confusion, loss of balance, or convulsions.

[edit] Diagnosis and treatment

In CNS infection cases, L. monocytogenes can often be cultured from the blood, and always cultured from the CSF. There are no reliable serological or stool tests.

Bacteremia should be treated for 2 weeks, meningitis for 3 weeks, and brain abscess for at least 6 weeks. Ampicillin generally is considered antibiotic of choice; gentamicin is added frequently for its synergistic effects. Overall mortality rate is 20-30%; of all pregnancy-related cases, 22% resulted in fetal loss or neonatal death, but mothers usually survive.[citation needed]

[edit] Prevention

The main means of prevention is through the promotion of safe handling, cooking and consumption of food. This includes washing raw vegetables and cooking raw food throroughly, as well as reheating leftover or ready-to-eat foods like hot dogs until steaming hot. [5]

Another aspect of prevention is in giving advice to high-risk groups such as pregnant women and immunocompromised patients to avoiding unpasteurised pâtés and foods such as soft cheeses like feta, Brie, Camembert cheese, bleu. Cream cheese, yogurt, and cottage cheese are considered safe. In the United Kingdom, advice along these lines from the Chief Medical Officer posted in maternity clinics led to a sharp decline in cases of listeriosis in pregnancy in the late 1980s [6]

[edit] See also

[edit] References

  1. ^ a b Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9. 
  2. ^ Hof H (1996). Listeria Monocytogenes in: Baron's Medical Microbiology (Baron S et al, eds.), 4th ed., Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1. 
  3. ^ Center for Infectious Disease Research & Policy, University of MinnesotaListeriosis
  4. ^ Smittskyddsinstitutet – [1]
  5. ^ Listeriosis. CDC: Division of Bacterial and Mycotic Diseases. Retrieved on 2006-05-02.
  6. ^ Skinner et al. (1996). "Listeria: the state of the science Rome 29–30 June 1995 Session IV: country and organizational postures on Listeria monocytogenes in food Listeria: UK government's approach" 7: 245-247. Food control. 

[edit] External links