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.

Development of an equine coronavirus–specific enzyme-linked immunosorbent assay to determine serologic responses in naturally infected horses

“…1,12 In the present study, all 15 diseased and EqCoV qPCR-positive horses had evidence of specific antibodies to EqCoV in the convalescent serum samples, which reflects the high sensitivity of the S protein-based ELISA. The present ELISA was based on recombinant S protein of EqCoV because of the technical difficulty in growing large amounts of EqCoV.…”

Passive immunity to control Bovine coronavirus diarrhea in a dairy herd in Argentina

“…Regarding the prevalence of BCoV, serological surveys indicate that approximately 90% of the worldwide cattle population has Abs against BCoV 8 . However, Ohlson et al 31 observed that BCoV Ab-positive herds remained persistently high (75---100%) in Swedish Southern regions compared with Northern regions where the percentage of positive herds were lower (38---80%). In Argentina, 100% of the adult cattle population is estimated to be seropositive for Abs to CoVB (Dr. Parreño, personal communication).…”

“…The incidence of BCoV varies between 15% and 70% in naturally occurring outbreaks worldwide 25,27,31 . In the Southern hemisphere, Al Mawly et al 1 detected a BCoV prevalence of 14% during 2011 calving season in dairy farms in New Zealand.…”

Herd level estimation of probability of disease freedom applied on the Norwegian control program for bovine respiratory syncytial virus and bovine coronavirus

“…Transmission dynamics for BCV has not yet been investigated in Norway, although one study describes a regional outbreak of winter dysentery (Toftaker et al, 2017). Studies from Sweden have shown that recent BCV infection is common, indicating that the infection is easily transmitted (Beaudeau et al, 2010;Ohlson et al, 2013). Due to the constant risk of virus introduction, the assumption that a negative status is valid for a long time is questionable.…”