Molecular epidemiology of two US orbiviruses: bluetongue virus and epizootic hemorrhagic disease virus.

The degree of relatedness between 4 US serotypes (10, 11, 13 and 17) of bluetongue (BT) virus (BTV) were determined by both oligonucleotide fingerprint analyses of double-stranded (ds) RNA as well as tryptic peptide analyses of viral coded polypeptides. Similar studies were undertaken using different alternate isolates of particular serotypes as well as 2 serotypes (1 and 2) of epizootic hemorrhagic disease (EHD) virus (EHDV), a closely related serogroup of orbiviruses. The results indicate that all BT viruses are genetically related to each other and although EHDV-1 and EHDV-2 originated from a common gene pool, the 2 serogroups, EHDV and BTV, are not genetically interactive.