Isolation of Francisella tularensis and Powassan virus from ticks (Acari: Ixodidae) in Ontario, Canada.

This study was undertaken to increase knowledge of the tick-borne arboviruses and of Francisella tularensis in Ontario, Canada. A total of 464 Ixodes cookei , 3 I. angustus , and 507 Dermacentor variabilis were collected and separated in 59 pools. Six isolates were obtained, including 5 isolates of F. tularensis from D. variabilis collected on the Six Nations Indian Reserve near Brantford in 1979 and 1 isolate of Powassan (POW) virus from a pool of I. cookei collected near Guelph in 1981. An additional isolate of POW virus was obtained from a yearling Woodchuck ( Marmota monax ) near Guelph. Complement-fixing antibodies to F. tularensis were demonstrated in a dog on the Six Nations Reserve. Hemagglutination-inhibiting and neutralizing antibodies to POW were demonstrated in Striped Skunk ( Mephitis mephitis ), Woodchuck, and dog sera from several parts of Ontario.