Difference between revisions of "Bovine Parainfluenza - 3"
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*On its own causes [[Rhinitis#Infectious causes of rhinitis|rhinitis]] | *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 | *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 [[ | + | *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]] | *Early stages may show [[Cellular Inclusions|intracytoplasmic inclusions]] | ||
*The resulting exudate is predominantly neutrophilic | *The resulting exudate is predominantly neutrophilic | ||
Revision as of 18:30, 19 February 2011
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This article is still under construction. |
PI3
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
- Causative agent: parainfluenza- 3 virus (PI3)
- On its own causes rhinitis
- Often part of multi-aetiology disease complex (e.g. Enzootic pneumonia of calves), often followed by Pasteurella sp. obscuring viral origin
- Replicates in airway epithelial cells and results in an initial bronchitis -> bronchiolitis -> extension into alveoli, causing bronchointerstitial pneumonia
- Early stages may show 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