Difference between revisions of "Porcine Reproductive and Respiratory Syndrome"
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| − | + | Also known as: PRRS | |
| + | ==Description== | ||
| + | *The syndrome is caused by a small enveloped RNA virus which belongs to the new [[Arteriviridae|Arteriviridae]] group | ||
| + | *Replicates in and destroys macrophages and endothelial cells causing vasculitis -> viraemia -> virus shedding (nasal secretions, faeces) | ||
| + | *Clinical signs: respiratory and reproductive failure, weaned pigs, tachypnoea, eyelid oedema, conjunctivitis | ||
| + | *Moderate to severe interstitial [[Lungs Inflammatory - Pathology#Infectious causes of pneumonia|pneumonia]] in the cranial lobe | ||
| + | *Superimposed bacterial infections are common | ||
| + | *Infectious disease in swine that emerged 10 years ago | ||
| + | *Today, PRRS is endemic in many if not all the pig-producing countries | ||
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| + | PRRS Porcine reproductive and respiratory syndrome virus (Lelystad virus). There is abortion late in gestation with respiratory tract illness in live piglets (interstitial pneumonia). | ||
| + | |||
| + | ==Virus== | ||
====Antigenicity==== | ====Antigenicity==== | ||
*Isolates vary in virulence | *Isolates vary in virulence | ||
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*Pigs: aka '''Blue Ear''' or '''Lelystad virus''' | *Pigs: aka '''Blue Ear''' or '''Lelystad virus''' | ||
| − | ==== | + | ==Transmission and Epidemiology== |
| + | *Discovered in Holland in 1990 | ||
| + | *'''Highly contagious''' | ||
| + | *Survives well on '''fomites''' | ||
| + | *Transfer may also be '''aerosol''' or via '''semen''' | ||
| + | *Exacerbated by immunosuppression (eg by porcine circovirus 2) | ||
| + | |||
| + | ==Pathogenesis== | ||
*Infects alveolar macrophages, followed by '''interstitial pneumonitis''' | *Infects alveolar macrophages, followed by '''interstitial pneumonitis''' | ||
*Persistent infection of '''[[Monocytes]]''' followed by '''leukopenia and thrombocytopenia''' | *Persistent infection of '''[[Monocytes]]''' followed by '''leukopenia and thrombocytopenia''' | ||
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*Transplacental spread leads to '''abortion, mummification, or resorption''' | *Transplacental spread leads to '''abortion, mummification, or resorption''' | ||
| − | ==== | + | ==Diagnosis== |
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| − | === | + | ===Clinical Signs=== |
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**Thumping respiration | **Thumping respiration | ||
**Abortions | **Abortions | ||
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**Eyelid oedema | **Eyelid oedema | ||
**Weak or dying piglets | **Weak or dying piglets | ||
| + | |||
| + | ===Laboratory Tests+ | ||
*'''ELISA''' for virus '''antibody''' | *'''ELISA''' for virus '''antibody''' | ||
*Rising antibody titres as a retrospective diagnosis (4X increase) | *Rising antibody titres as a retrospective diagnosis (4X increase) | ||
| − | + | ==Control== | |
*Certified '''Specific Pathogen Free''' units exclude by quarantine | *Certified '''Specific Pathogen Free''' units exclude by quarantine | ||
*Management: all in/all out, screening AI semen | *Management: all in/all out, screening AI semen | ||
*'''Vaccine''' available | *'''Vaccine''' available | ||
| + | ==Prognosis== | ||
| − | === | + | ==Links== |
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| + | ==References== | ||
[[Category:Arteriviridae]] | [[Category:Arteriviridae]] | ||
Revision as of 15:49, 27 August 2010
 |
This article is still under construction. |
Also known as: PRRS
Description
- The syndrome is caused by a small enveloped RNA virus which belongs to the new Arteriviridae group
- Replicates in and destroys macrophages and endothelial cells causing vasculitis -> viraemia -> virus shedding (nasal secretions, faeces)
- Clinical signs: respiratory and reproductive failure, weaned pigs, tachypnoea, eyelid oedema, conjunctivitis
- Moderate to severe interstitial pneumonia in the cranial lobe
- Superimposed bacterial infections are common
- Infectious disease in swine that emerged 10 years ago
- Today, PRRS is endemic in many if not all the pig-producing countries
PRRS Porcine reproductive and respiratory syndrome virus (Lelystad virus). There is abortion late in gestation with respiratory tract illness in live piglets (interstitial pneumonia).
Virus
Antigenicity
- Isolates vary in virulence
- Some are subclinical
Hosts
- Pigs: aka Blue Ear or Lelystad virus
Transmission and Epidemiology
- Discovered in Holland in 1990
- Highly contagious
- Survives well on fomites
- Transfer may also be aerosol or via semen
- Exacerbated by immunosuppression (eg by porcine circovirus 2)
Pathogenesis
- Infects alveolar macrophages, followed by interstitial pneumonitis
- Persistent infection of Monocytes followed by leukopenia and thrombocytopenia
- Mostly affects piglets
- In adults, cyanotic appearance due to vascular lesions
- Transplacental spread leads to abortion, mummification, or resorption
Diagnosis
Clinical Signs
- Thumping respiration
- Abortions
- Flushed skin
- Eyelid oedema
- Weak or dying piglets
===Laboratory Tests+
- ELISA for virus antibody
- Rising antibody titres as a retrospective diagnosis (4X increase)
Control
- Certified Specific Pathogen Free units exclude by quarantine
- Management: all in/all out, screening AI semen
- Vaccine available