ABSTRACT
This chapter will address the biology, epidemiology and ecology, pathology, and diagnostics of Powassan Virus (POWV) and Deer Tick viruse lineage I and II. It says that the viruses are conserved over distance, as demonstrated by POWV isolated from a human case in Russia, in 2006, which was 99.8% similar to the strain that was isolated in Canada in 1958. In this chapter, POWV includes both lineage I and II. It says that the first reported case of POW encephalitis occurred in Ontario, Canada, in 1958. Upto 2005, many cases of POWV disease were reported in the United States and Canada. This chapter says that the first case of POW encephalitis was reported in Russia in 1973 and many cases were reported till 1989 and its symptoms in Russia included fever, headache, nausea, vomiting, fatigue, drowsiness, neurological and meningeal symptoms, paralysis, seizures, cerebellar ataxia, and spastic hemiparesis. A number of studies examining the pathogenesis of POWV have been published.
