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Listeria

Listeria

  1. What is listeriosis?
  2. What effects does listeria have in human pregnancy?
  3. Is there any risk of later consequences?
  4. What are the symptoms of the disease in humans?
  5. How is the infection acquired?
  6. How common is this infection?
  7. What tests are available to confirm the diagnosis?
  8. Is there any effective treatment?
  9. Is there any vaccine?
  10. If one pregnancy is affected by listeria, are subsequent pregnancies likely to be at any risk?
  11. Is the infection common in sheep in Great Britain?
  12. What are the manifestations of disease in sheep?
1. What is listeriosis?

Listeriosis is a disease caused by the bacterium Listeria monocytogenes. This disease can cause serious disease in the unborn or newborn child. The disease may be transmitted by contact with infected animals or ingestion of contaminated food.

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2. What effects does listeria have in human pregnancy?

Infection may cause abortion or premature birth. Infection in utero or during delivery may lead to septicaemia and meningitis with a 50-100% mortality.

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3. Is there any risk of later consequences?

Infection in the newborn may take the form of disseminated granulomatous disease, involving many organs including respiratory tract, eyes and nervous system.

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4. What are the symptoms of the disease in humans?

Infection in pregnancy generally presents as a mild flu-like illness.

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5. How is the infection acquired?

Infection is acquired by ingestion and most cases are probably the result of consumption of infected food. If contact with ewes at lambing time is unavoidable, washing of the hands after handling animals should prevent any possibility of infection.

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6. How common is this infection

There are usually up to 25 cases of listeriosis in pregnancy reported annually in the UK, but it is not known how many of these, if any, are associated with contact with sheep.

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7. What tests are available to confirm the diagnosis?

The diagnosis may be made by culturing the organism from the mother's blood or faeces.

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8. Is there any effective treatment?

Listeria monocytogenes is sensitive to a number of antibiotics.

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9. Is there any vaccine?

No.

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10. If one pregnancy is affected by listeria, are subsequent pregnancies likely to be at any risk?

No. Chronic or recurrent infection in expectant mothers is not associated with foetal infection.

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11. Is the infection common in sheep in Great Britain?

Listeria infection accounts for only 1-2% of sheep abortion incidents reported and diagnosed in Great Britain each year. The numbers of abortions incidents recorded by Defra veterinary laboratories for 1991-2002 ranged from 22 - 82 incidents each year (31 in 2002).

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12. What are the manifestations of disease in sheep?

Abortion from 12 weeks of pregnancy onwards. There may be occasional deaths in ewes. Encephalitis due to listeria infection may also be seen in sheep, but is not generally associated with abortions.

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Page updated: Tuesday, November 22, 2005