Prevalence and genetic characterization of Powassan virus strains infecting Ixodes scapularis in Connecticut.
A total of 30 Powassan virus (POWV) isolates from Ixodes scapularis collected from Bridgeport and North Branford, CT in 2008, 2010, 2011, and 2012 and one earlier isolate from Ixodes cookei collected in Old Lyme, CT in 1978 were characterized by phylogenetic analysis of their envelope gene sequences. Powassan virus sequences segregated into two major groups termed the deer tick virus (DTV) and Powassan (POW) lineages. The lineage from I. cookei was POW. The remaining viruses from I. scapularis grouped with the DTV lineage. Powassan viruses from Bridgeport were nearly identical and clustered with a virus strain from a human in New York. Viruses from North Branford were homogeneous and grouped with viruses from Massachusetts, northwestern Connecticut, and Ontario. These findings suggest that POWV was independently introduced into these geographical locations in Connecticut and maintained focally in their respective environments. An improved method of isolation of POWV in vitro is described.
Department of Entomology and Center for Vector Biology and Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, CT 06504-1106, USA. John.F.Anderson@CT.Gov
John F
JF
Anderson
Philip M
PM
Armstrong
D000818:Animals; D003237:Connecticut; D004669:Encephalitis Viruses, Tick-Borne / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D018884:Ixodes / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D017422:Sequence Analysis, DNA