title: Patterns of detection of respiratory viruses in nasal swabs from calves in Ireland: a retrospective study.
abstract: A retrospective analysis was conducted to investigate the prevalence and seasonality of bovine viral diarrhoea virus (BVDV), bovine coronavirus (BoCV), bovine herpesvirus-1 (BoHV-1), bovine respiratory syncytical virus (BRSV) and parainfluenza virus-3 (PI3V) in calves (aged three months and below) in Ireland. Results from real-time PCR testing, including cycle threshold values, conducted on nasal swabs (single or pooled) submitted from 1364 respiratory disease outbreaks between January 1, 2008 and December 31, 2012 were included in this study. One or more viruses were detected in 34.6 per cent of submissions, with BoCV detected most frequently (22.9 per cent), followed by BRSV (11.6 per cent), PI3 V (7.0 per cent), BoHV-1 (6.1 per cent) and BVDV (5.0 per cent). The detection rate of all viruses was higher when pooled multiple swabs were submitted from outbreaks rather than single swabs, with these differences being significant for all except BVDV. Two or more viruses were detected in 39.4 per cent of positive submissions, with BoCV and BRSV most commonly present as one of the two partners in detection. With the exception of BVDV, which was detected all year round, the others showed a clear seasonal pattern, being most commonly detected in winter and spring.
authors.affiliation: Virology Division, DAFM Veterinary Labs, Celbridge, Kildare, Ireland.
authors.forename: R
authors.initials: R
authors.lastname: O'Neill
authors.affiliation: Virology Division, DAFM Veterinary Labs, Celbridge, Kildare, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Mooney
authors.affiliation: Virology Division, DAFM Veterinary Labs, Celbridge, Kildare, Ireland.
authors.forename: E
authors.initials: E
authors.lastname: Connaghan
authors.affiliation: Virology Division, DAFM Veterinary Labs, Celbridge, Kildare, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Furphy
authors.affiliation: Animal Health Ireland, Main Street, Carrick on Shannon, Ireland.
authors.forename: D A
authors.initials: DA
authors.lastname: Graham
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000453:epidemiology; D017938:Coronavirus, Bovine / Q000302:isolation & purification*; D001908:Diarrhea Viruses, Bovine Viral / Q000302:isolation & purification*; D005260:Female; D007242:Herpesvirus 1, Bovine / Q000302:isolation & purification*; D007494:Ireland / Q000453:epidemiology; D008297:Male; D009296:Nasal Cavity / Q000821:virology*; D029101:Parainfluenza Virus 3, Bovine / Q000302:isolation & purification*; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D018112:Respiratory Syncytial Virus, Bovine / Q000302:isolation & purification*; D012189:Retrospective Studies; D012621:Seasons