Changes

Jump to navigation Jump to search
no edit summary
Line 1: Line 1: −
{{unfinished}}
+
{{OpenPagesTop}}
 +
Also known As: '''''Bovine PI-3'''''
   −
PI3
+
== Introduction  ==
   −
====Pathogenesis====
+
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.
*Virulence varies with isolates
  −
*Cessation of [[Respiratory System General Introduction - Pathology#Mucociliary escalator|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 34<sup>o</sup>C but not at 37<sup>o</sup>C
  −
**Re-infection is common
  −
====Secondary Concerns====
  −
*With other agents causes [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|calf pneumonia ]]
  −
*Associated with poor management:
  −
**Overcrowding
  −
**Poor ventilation
  −
**High humidity
  −
**Deprivation of colostrum
  −
**Stress caused by transport or mixing of stock
      +
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.
   −
*Causative agent: [[Paramyxoviridae#Bovine Parainfluenza - 3 (PI-3)|parainfluenza- 3 virus]] (PI3)
+
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.
*On its own causes [[Rhinitis#Infectious causes of rhinitis|rhinitis]]
  −
*Often part of multi-aetiology disease complex (e.g. [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|Enzootic pneumonia of calves]]), often followed by [[:Category:Pasteurella and Mannheimia species|''Pasteurella sp.'']] obscuring viral origin
  −
*Replicates in airway epithelial cells and results in an initial [[Bronchitis#Infectious causes of bronchitis or bronchiolitis|bronchitis -> bronchiolitis]] -> extension into [[Pneumonia Overview#Infectious causes of pneumonia|alveoli]], causing [[Bronchointerstitial Pneumonia|bronchointerstitial pneumonia]]  
  −
*Early stages may show [[Cellular Inclusions|intracytoplasmic inclusions]]
  −
*The resulting exudate is predominantly neutrophilic
  −
*Positive confirmation lies in a Fluorescent Antibody Test (FAT) to the specific virus on frozen sections of tissue
      +
== Signalment ==
    +
This affects any bovid of any age, but most commonly calves or cattle housed over winter.
   −
[[Category:Paramyxovirinae]]
+
== Clinical Signs ==
[[Category:Cattle Viruses]]
+
 
[[Category:Respiratory Diseases - Cattle]]
+
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.
[[Category:To_Do_-_Clinical/Viruses]]
+
 
[[Category:Respiratory_Viral_Infections]]
+
== Diagnosis  ==
 +
 
 +
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.
 +
 
 +
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).
 +
 
 +
Positive confirmation lies in a [[Immunofluorescence|Fluorescent Antibody Test (FAT)]] to the specific virus on frozen sections of tissue.
 +
 
 +
== Treatment and Control  ==
 +
 
 +
Treatment can be given to help secondary bacterial infections.
 +
 
 +
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]]
Author, Donkey, Bureaucrats, Administrators
53,803

edits

Navigation menu