New page: {{unfinished}} {{toplink |linkpage =Viruses |linktext =VIRUSES |sublink1=Paramyxoviridae |subtext1=PARAMYXOVIRIDAE |pagetype =Bugs }} <br> ====Pathogenesis==== *More serious than [[Para...
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====Pathogenesis====
*More serious than [[Paramyxoviridae#Parainfluenza -3 (PI-3)|PI-3]]
*Causes [Respiratory Viral Infections - Pathology#Respiratory syncytial virus|respiratory infection]]
*Replicates in nasal epithelium -> throughout upper respiratory tract -> bronchial tree
*Syncytia form -> shed into bronchioles
*Complications include [[Lungs Ventilation - Pathology#Emphysema|emphysema]] and [[Lungs Circulatory - Pathology#Pulmonary oedema|oedema]], drop in milk yield in adult cattle
====Epidemiology====
**Subclinical reinfections are important in spreading disease
**More than 70% of cattle in the UK have antibodies to BRSV
====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 husbansry as in [[Paramyxoviridae#Parainfluenza -3 (PI-3)|PI-3]]
*Vaccines are available but not effective as need to stimulate [[Lymphocytes - WikiBlood#Cytotoxic CD8+|cytotoxic T-cells]]
====Secondary Concerns====
*<small>'''Reference''': Bryson, 1999, Update on calf pneumonia, CPD Veterinary Medicine, 1,3, 90-95</small>
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