Difference between revisions of "Bovine Parainfluenza - 3"

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Also known As: '''''Bovine PI-3'''''
 
  
== Introduction  ==
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|linktext =VIRUSES
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|sublink1=Paramyxoviridae
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|subtext1=PARAMYXOVIRIDAE
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This virus is of the family [[:Category:Paramyxovirinae|paramyxoviridae]] and its virulence varies with isolates. Alone, this virus does not usually produce severe disease in cattle, but with other agents such [[Bovine Respiratory Syncytial Virus]], [[Infectious Bovine Rhinotracheitis]] and bacteria such as [[:Category:Pasteurella and Mannheimia species|''Mannheimia'']] and [[:Category:Mycoplasmas|''Mycoplasmas'']], makes up the [[Enzootic Pneumonia - Calves|enzootic pneumonia complex]] which mostly affects calves.
 
  
Occurence of the disease is usually thought to be due to stress such as mixing of animals of different age groups, transport and winter housing. Poor hygiene also contributes to this.
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====Pathogenesis====
 
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*Virulence varies with isolates
The virus causes cessation of [[Respiratory System General Introduction - Pathology#Mucociliary_escalator|ciliary clearance]] and epithelial necrosis, which predisposes to secondary bacterial infections and can leading to clinical signs. This occurs due to replication in airway epithelial cells causing an initial [[bronchitis]], which may lead to bronchiolitis and then extension into alveoli, causing [[Bronchointerstitial Pneumonia|bronchointerstitial pneumonia]]. Early stages may show intracytoplasmic inclusions and the resulting exudate is predominantly neutrophilic.
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*Cessation of [[Respiratory System General Introduction - Pathology#Mucociliary escalator|ciliary clearance]] and epithelial necrosis predisposes to secondary bacterial infections -> cough
 
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*May cause [[Respiratory Viral Infections - Pathology#Parainfluenza- 3|rhinitis]] of cattle
== Signalment ==
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====Diagnosis====
 
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*Diseased lung tissue from dead animals or centrifuged cells from lung lavage
This affects any bovid of any age, but most commonly calves or cattle housed over winter.
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*Virus is too fragile for cell culture isolation (often inactivated in transport)
 
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*Antigen detection by ''' immunocytochemistry''' for intracytoplasmic viral inclusions containing labelled viral protein
== Clinical Signs ==
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*Serology: 4-fold rise in ELISA antibody in paired serum samples from several animals
 
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====Control====
This virus may cause [[rhinitis]] of cattle when acting alone and with secondary infections may cause signs such as coughing and nasal discharge. If involved in calf pneumonia complex, then signs relating to that will also be seen such as dyspnoea, coughing, increased respiratory rate and general malaise.
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*Improve managemental factors
 
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*All-in, all-out systems
== Diagnosis  ==
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*Some vaccination
 
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**Temperature sensitive mutant that replicates at 34<sup>o</sup>C but not at 37<sup>o</sup>C
In many cases, history and clinical signs are diagnostic, especially when in complex with other disease. If the agent is acting alone, many cattle will not show any clinical signs.
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**Re-infection is common
 
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====Secondary Concerns====
Diagnosis can be made from diseased lung tissue from dead animals or centrifuged cells from lung lavage. The virus is too fragile for cell culture isolation (often inactivated in transport). Antigen detection by '''immunocytochemistry''' for intracytoplasmic viral inclusions containing labelled viral protein can be performed. Serology can also be performed and a 4-fold rise in [[ELISA testing|ELISA]] antibody in paired serum samples from several animals is indicative of the disease. A first, acute phase sample should be taken and another sample taken around 2 weeks after this (convalescent stage).
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*With other agents causes [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|calf pneumonia ]]
 
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*Associated with poor management:
Positive confirmation lies in a [[Immunofluorescence|Fluorescent Antibody Test (FAT)]] to the specific virus on frozen sections of tissue.
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**Overcrowding
 
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**Poor ventilation
== Treatment and Control ==
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**High humidity
 
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**Deprivation of colostrum
Treatment can be given to help secondary bacterial infections.
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**Stress caused by transport or mixing of stock
 
 
Control measures include improving managemental factors, such as using all-in all-out systems, preventing mixing of groups of stock and increased ventilation in housing. Preventing overcrowding, humidity and stress are key factors. In calves it is important to ensure passive transfer occurs as a [[Failure of Passive Transfer|lack of colostrum]] will greatly increase the risk of disease.
 
 
 
Some vaccination does occur and is available in the UK. Immunity does not last and re-infection is common.
 
 
 
== References ==
 
 
 
Andrews, A.H, Blowey, R.W, Boyd, H and Eddy, R.G. (2004) '''Bovine Medicine '''(Second edition), ''Blackwell Publishing''
 
 
 
Blood, D.C. and Studdert, V. P. (1999) '''Saunders Comprehensive Veterinary Dictionary''' (2nd Edition), ''Elsevier Science''
 
 
 
Bridger, J and Russel, P (2007) '''Virology study guide, '''''Royal Veterinary College''
 
 
 
Merck & Co (2008) '''The Merck Veterinary Manual''' (Eighth Edition), ''Merial''
 
 
 
Radostits, O.M, Arundel, J.H, and Gay, C.C. (2000) '''Veterinary Medicine: a textbook of the diseases of cattle, sheep, pigs, goats and horses, '''''Elsevier Health Sciences''
 
 
 
 
 
{{review}}
 
 
 
{{OpenPages}}
 
 
 
[[Category:Paramyxovirinae]] [[Category:Cattle_Viruses]] [[Category:Respiratory_Diseases_-_Cattle]] [[Category:Expert_Review - Farm Animal]] [[Category:Respiratory_Viral_Infections]]
 

Revision as of 18:48, 13 October 2008



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VIRUSES
PARAMYXOVIRIDAE




Pathogenesis

  • Virulence varies with isolates
  • Cessation of ciliary clearance and epithelial necrosis predisposes to secondary bacterial infections -> cough
  • May cause rhinitis of cattle

Diagnosis

  • Diseased lung tissue from dead animals or centrifuged cells from lung lavage
  • Virus is too fragile for cell culture isolation (often inactivated in transport)
  • Antigen detection by immunocytochemistry for intracytoplasmic viral inclusions containing labelled viral protein
  • Serology: 4-fold rise in ELISA antibody in paired serum samples from several animals

Control

  • Improve managemental factors
  • All-in, all-out systems
  • Some vaccination
    • Temperature sensitive mutant that replicates at 34oC but not at 37oC
    • Re-infection is common

Secondary Concerns

  • With other agents causes calf pneumonia
  • Associated with poor management:
    • Overcrowding
    • Poor ventilation
    • High humidity
    • Deprivation of colostrum
    • Stress caused by transport or mixing of stock