New records of the Lyme disease bacterium in ticks collected from songbirds in central and eastern Canada

This study highlights the collection of ticks from wild-caught birds in central and eastern Canada. Using polymerase chain reaction (PCR), 32 (33%) of 98 Ixodes species ticks tested were positive for the Lyme disease bacterium, Borrelia burgdorferi sensu lato (s.l.) Johnson, Schmid, Hyde, Steigerwalt, and Brenner (hereafter B. burgdorferi). Immature blacklegged ticks, Ixodes scapularis Say, which are competent vectors of B. burgdorferi, constituted the predominant Ixodes species tick collected from parasitized songbirds; specifically, 31(35%) of 89 I. scapularis nymphs were positive for B. burgdorferi. Notably, we report the first B. burgdorferi-positive I. scapularis (nymph) on a migratory passerine in Prince Edward Island; this is the first record of a tick on a bird in this maritime province. First-time records of B. burgdorferi-infected, I. scapularis nymphs on passerines in northwestern Ontario include rose-breasted grosbeak, Pheucticus ludovicianus (Linnaeus), eastern bluebird, Sialia sialis (L.), and indigo bunting, Passerina cyanea (L.). Similarly, we furnish a new host record in Canada for an I. scapularis (nymph) on a worm-eating warbler, Helmitheras vermivorus (Gmelin); this engorged nymph tested positive for B. burgdorferi. We document the first recorded collection of a B. burgdorferi-infected Ixodes muris Bishopp and Smith (female) on a songbird in Ontario. We provide the first account of a live culture of B. burgdorferi from an I. scapularis (nymph) collected from a brown-headed cowbird Molothrus ater (Boddaert) in Manitoba. We make available new host records for I. scapularis on a clay-coloured sparrow Spizella pallida (Swainson) and a Gambels white-crowned sparrow Zonotrichia leucophrys gambelii (Nuttall). An I. scapularis on a songbird during southward autumn migration in northwestern Ontario is a first record reported. As well, we document the first-ever account of a reptile-associated tick, a nymph of Amblyomma sabanerae Stoll, on a veery Catharus fuscescens (Stephens) in northwestern Ontario. Migratory songbirds play an integral role in the wide dispersal of B. burgdorferi-infected ticks, especially during northward spring migration. Clinicians need to be aware that people can be bitten by B. burgdorferi-infected ticks released by songbirds across Canada.