Isolation of Francisella Tularensis and Powassan Virus from Ticks (Acari: Ixodidae) in Ontario, Canada1

The Biological Survey of Canada: A Personal History

“…Ticks play a prominent role in the transmission of F. tularensis to humans, accounting for more than 50% of all cases, especially west of the Mississippi River (Eisen et al 2008 (Humphreys and Campbell 1947;Gordon et al 1983). In Ontario, F. tularensis has been isolated from Haemaphysalis leporispalustris (Ditchfield et al 1960) and Dermacentor variabilis (Artsob et al 1984) and from beavers, muskrats, and cats (Labzoffsky and Sprent 1952;Ditchfield et al 1960).…”

“…The pathogens responsible for Lyme disease, tularaemia, and Rocky Mountain spotted fever in humans have been isolated or detected in D. variabilis collected in Canada (Artsob et al 1984;Lindsay et al 1991;Artsob 1996); however, the probability of acquiring a tick-borne pathogen from this species is very low. Despite numerous reports in the United States of America (Anonymous 1996), paralysis of humans (or animals) caused by D. variabilis has never been reported in Canada (Gregson 1973).…”

“…In Canada, Ixodes cookei is primarily associated with the woodchuck, Marmota monax, where prevalence has been reported from 29-50% (McLean et al 1966;Ko 1972a;Artsob et al 1984;Farkas and Surgeoner 1990), though Martell et al (1969) found three of seven porcupines infested in Nova Scotia. In southern parts of its range, mediumsized mammals, especially raccoons and skunks, are important hosts (e.g., Sonenshine 1979b; Kollars and Oliver 2003).…”

“…Therefore, it may be of importance to human health. Its role in transmission of Powassan virus is well known (Main et al 1979), and as many as 23% of woodchucks in Ontario were shown to be seropositive (Artsob et al 1984). This species has not proven to be a good vector of the bacterium that causes Lyme borreliosis (Barker et al 1993), but there are indications that it may be a vector of other potential pathogens elsewhere in its range (Magnarelli and Swihart 1991).…”

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

“…The POW virus and DT virus strains used in this study are listed in Table 1. 1,[3][4][5][6][7][8][9][10] Two strains (ON58 and ON97) were isolated from human brain; strain WV77 was isolated from brain of a fox. Except for strain CO58, which was isolated from Dermacentor tick, the remainder of strains were isolated from Ixodid ticks.…”