First detection of Lyme disease spirochete Borrelia burgdorferi in ticks collected from a raptor in Canada

During a pan-Canadian tickhost study, we detected the spirochetal bacterium, Borrelia burgdorferi sensu lato, which causes Lyme disease, in ticks collected from a raptor. Lyme disease is one of a number of zoonotic, tick-borne diseases causing morbidity and mortality worldwide. Larvae of the avian coastal tick, Ixodes auritulus, were collected by wildlife rehabilitators from a Cooper's hawk, Accipiter cooperii, on Vancouver Island, British Columbia. Using PCR amplification of the linear plasmid ospA gene of B. burgdorferi, 4 (18%) of 22 larvae were positive. Since these engorged I. auritulus larvae had not had a previous blood meal and B. burgdorferi is rarely transmitted from infected female ticks to their progeny, we propose that Cooper's hawks are reservoircompetent hosts of B. burgdorferi. Our tick-host discovery provides the first report of bird-feeding ticks on a Cooper's hawk, and exhibits the premiere record of B. burgdorferi-positive ticks on a raptor. Not only are passerine (perching) and gallinaceous (chicken-like) birds involved in the wide dispersal of Lyme disease vector ticks, raptors are now also implicated in the dissemination of B. burgdorferi-infected ticks. Although I. auritulus does not bite humans, this tick species plays an integral role in the 4-tick enzootic cycle of B. burgdorferi along the West Coast of North America. In essence, raptors and I. auritulus ticks may help to amplify this infectious agent in nature, and increase the likelihood of people contracting Lyme disease, especially in coastal areas.