Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 6/2/1999
Publication Date: N/A
Technical Abstract: Respiratory bovine coronavirus (RBCV) infections were never detected or isolated in numerous etiological investigations of shipping fever epizootics. The RBCV were first isolated when our novel technology of virus isolation was developed and applied in 1993 during an initial screening of cattle arriving at feedlots with respiratory distress. This technology detects all known viruses infecting the respiratory tracts of cattle. Serological and antigen detection tests related this type of virus as a potential cause of other forms of respiratory tract diseases of young calves, but the involvement of RBCV in epizootics of shipping fever was not suspected. It is imperative that appropriate tests for RBCV detection be included in laboratory diagnostic approaches for problems of respiratory tract diseases among cattle. The gold standard for RBCV detection is isolation in G clone cell cultures while capture with panels of monoclonal antibodies also proved effective. Genetic tools with nested polymerase chain reactions are promising in detecting and differentiating RBCV from enteric bovine coronavirus (EBCV). The patterns of rapid spread and high rates of infection at the beginning of these epizootics furnish strong evidence for an inciting etiological role of RBCV for respiratory tract disease which affect the cattle in order buyer barns (OBB) and in feedyards. Significantly, cattle with antibodies against RBCV at the time of first sampling in the OBB remained clinically normal during these epizootics. The bovine herpesvirus-1 (BHV-1) infection virtually did not spread among the cattle while the RBCV spread rapidly. The cattle were vaccinated with a modified live virus vaccine containing BHV-1 and parainfluenza-3 (PI-3).