title: A longitudinal study of the dynamics of bovine corona virus and respiratory syncytial virus infections in dairy herds.
abstract: The objective of this study was to examine the dynamics of bovine corona virus (BCV) and bovine respiratory syncytial virus (BRSV) infections in dairy herds over a 3-year period. The status of 79 dairy herds located in two Northern and two Southern Regions of Sweden were surveyed by measuring antibody concentrations to BCV and BRSV in pooled milk samples from primiparous cows, and in bulk-tank milk twice annually. In the Southern Regions the percentage of antibody-positive herds remained persistently high (75-100%), whereas in herds based in the Northern Region, the percentage of positive herds for BCV and BRSV was 38-80% and 0-80%, respectively, with antibody levels to BRSV decreasing over time. Pooled milk samples of 'home-bred' primiparous animals were found to be most useful in terms of monitoring herd status but could gradually be replaced by bulk-tank sampling once freedom from infection was established.
authors.affiliation: Department of Clinical Sciences, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07 Uppsala, Sweden. anna.ohlson@vxa.se
authors.forename: A
authors.initials: A
authors.lastname: Ohlson
authors.forename: S
authors.initials: S
authors.lastname: Alenius
authors.forename: M
authors.initials: M
authors.lastname: Tråvén
authors.forename: U
authors.initials: U
authors.lastname: Emanuelson
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D018352:Coronavirus Infections / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D017938:Coronavirus, Bovine; D005260:Female; D008137:Longitudinal Studies; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D012136:Respiratory Syncytial Viruses; D013548:Sweden / Q000453:epidemiology
keywords: Bovine corona virus; Bovine respiratory syncytial virus; Cattle; Herd monitoring; Longitudinal study; Serology