Genomic sequencing of deer tick virus and phylogeny of powassan-related viruses of North America

Powassan (POW) virus is responsible for central nervous system infection in humans in North America and the eastern parts of Russia. Recently, a new f lavivirus, deer tick (DT) virus, related to POW virus was isolated in the U nited States, but neither its pathogenic potential in human nor the taxonom ic relationship with POW virus has been elucidated. In this study, we obtai ned the near-full-length genomic sequence of the DT virus and complete sequ ences of 3 genomic regions of 15 strains of POW-related virus strains. The phylogeny revealed 2 lineages, one of which had the prototype POW virus and the other DT virus. Both lineages can cause central nervous system infecti on in humans. By use of the combination of molecular definition of virus sp ecies within the genus Flavivirus and serological distinction in a 2-way cr oss-neutralization test, the lineage of DT virus is classified as a distinc t genotype of POW virus.