Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 1998
Publication Date: N/A
Technical Abstract: Bovine viral diarrhea virus (BVDV) can be segregated into two genotypes, BVDV1 and BVDV2. Acute uncomplicated infections with BVDV1 are usually associated with mild or subclinical disease. BVDV2 have been reported as the cause of severe acute disease characterized by fever, pneumonia, diarrhea, and sudden death in all age groups. While severe acute disease are associated with BVDV2, not all BVDV2 cause severe acute disease. We compared naturally occurring virulent and avirulent BVDV2. BVDV2 were designated virulent or avirulent based on their ability to cause fever, leukopenia, and thrombocytopenia in infected cattle. Virulent and avirulent viruses grew to the same titer in cell cultures; however, in vivo, virulent viruses replicated to a higher titer. The rate of uptake of virulent BVDV2 by lymphocytes was greater than the uptake of avirulent BVDV2. Phylogeny based on comparison of 5' UTR or sequences coding for viral structural polypeptides did not segregate virulent BVDV2 or avirulent into distinct subgroups.