POWASSAN VIRUS IN Ixodes cookei AND MUSTELIDAE IN NEW ENGLAND

Prevalence and Genetic Characterization of Powassan Virus Strains Infecting Ixodes scapularis in Connecticut

“…Both of these subclades of the DTV lineage segregated from the POWV isolate from I. cookei collected in Old Lyme, CT in New London County. 11 This isolate was similar to other POW lineage viruses from New York and Ontario, Canada. These findings support previous studies reporting on the focal nature and distinct transmission cycles of the POW and DTV genotypes.…”

“…Not all of the methods used would have detected POWV, however, if present, the DTV lineage likely would have been isolated in suckling mice, a method successfully used to isolate the POW lineage from I. cookei collected in Old Lyme, CT in 1978. 11 Powassan virus was initially isolated from human brain tissue in suckling mice, which showed abnormal neurologic function. 2 Additional isolations of this virus from humans, wild animals, and from ticks were made similarly in the decades that followed.…”

“…2,13 Despite the absence of reported human POWV cases in Connecticut, human disease has been recognized in the adjoining state of New York, and the virus has been isolated from ticks in Connecticut. 11,12 In this study, we report 30 additional isolations of POWV from I. scapularis from two distinct geographical areas in Connecticut, an improved in vitro method for the isolation of this virus from ticks, the stability of two distinct genetic strains of POWV from two geographically separated populations over multiple years, and the focal nature of POWV.…”

“…[3][4][5][6][7] Powassan virus comprises two distinct genotypes, each with a distinct natural history and are known as POW (lineage 1) and deer tick virus (DTV) (lineage 2). [8][9][10] The POW lineage is maintained in an enzootic cycle involving mainly Ixodes cookei and Ixodes marxi and medium-sized mammals, such as red squirrels, Tamiasciurus hudsonicus, groundhogs, Marmota monax, and skunks, Mephitis sp., 1,11 whereas the DTV lineage has been isolated primarily from Ixodes scapularis. 1 Both lineages have been isolated from ticks, 11,12 and both have been isolated or detected in tissues from fatal human cases of encephalitis.…”

“…[8][9][10] The POW lineage is maintained in an enzootic cycle involving mainly Ixodes cookei and Ixodes marxi and medium-sized mammals, such as red squirrels, Tamiasciurus hudsonicus, groundhogs, Marmota monax, and skunks, Mephitis sp., 1,11 whereas the DTV lineage has been isolated primarily from Ixodes scapularis. 1 Both lineages have been isolated from ticks, 11,12 and both have been isolated or detected in tissues from fatal human cases of encephalitis. 2,13 Despite the absence of reported human POWV cases in Connecticut, human disease has been recognized in the adjoining state of New York, and the virus has been isolated from ticks in Connecticut.…”