Lyme disease is reported across Canada, but pinpointing the source of infection has been problematic. In this three-year, bird-tick-pathogen study (2004-2006), 366 ticks representing 12 species were collected from 151 songbirds (31 passerine species/subspecies) at 16 locations Canada-wide. Of the 167 ticks/pools tested, 19 (11.4%) were infected with Borrelia burgdorferi sensu lato (s.l.). Sequencing of the rrf-rrl intergenic spacer gene revealed four Borrelia genotypes: B. burgdorferi sensu stricto (s.s.) and three novel genotypes (BC genotype 1, BC genotype 2, BC genotype 3). All four genotypes were detected in spirochete-infected Ixodes auritulus (females, nymphs, larvae) suggesting this tick species is a vector for B. burgdorferi s.l. We provide first-time records for: ticks in the Yukon (north of 60 degrees latitude), northernmost collection of Amblyomma americanum in North America, and Amblyomma imitator in Canada.
First reports of bird-derived ticks infected with B. burgdorferi s.l. include: live culture of spirochetes from Ixodes pacificus (nymph) plus detection in I. auritulus nymphs, Ixodes scapularis in New Brunswick, and an I. scapularis larva in Canada.
We provide the first account of B. burgdorferi s. l. in an Ixodes muris tick collected from a songbird anywhere.
Congruent with previous data for the American Robin, we suggest that the Common Yellowthroat, Golden-crowned Sparrow, Song Sparrow, and Swainson's Thrush are reservoir-competent hosts. Song Sparrows, the predominant hosts, were parasitized by I. auritulus harboring all four Borrelia genotypes. Our results show that songbirds import B. burgdorferi s.l.-infected ticks into Canada. Bird-feeding I. scapularis subadults were infected with Lyme spirochetes during both spring and fall migration in eastern Canada. Because songbirds disperse millions of infected ticks across Canada, people and domestic animals contract Lyme disease outside of the known and expected range.
-------------------- Suspected Lyme 07 Test neg One band migrating in IgG region unable to identify.Igenex Jan.09IFA titer 1:40 IND IgM neg pos 31 +++ 34 IND 39 IND 41 IND 83-93 + DX:Neuroborreliosis Posts: 5850 | From Kentucky | Registered: Dec 2008
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Pinelady
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I. scapularis ticks were detected on 517 individual birds sampled at 17 of 19 study sites and 609 larvae were collected from 276 individual birds collected from 11 sites.
We detected Borrelia burgdorferi DNA in 98 out of 609 (16.1%) bird-derived I. scapularis larvae collected from 52 of 276 (18.7%) individual birds.
We obtained unambiguous sequence data from 63 samples and found that eight of the nine major B. burgdorferi IGS groups are transmissible by birds, although not at equal frequencies. Comparison with genotype frequencies detected in 781 host-seeking I. scapularis nymphs collected throughout the eastern United States
suggests that some IGS types are over-represented in birds, possibly indicating host-specialization to avian rather than mammalian hosts.
However, genotype frequencies are known to vary in space and time, so site specific variation may also partly explain the observed genotype-host association patterns. ------------- Could it be the diversity lies in the host/vector and not in the spirochetes themselves? As described as stealth?
-------------------- Suspected Lyme 07 Test neg One band migrating in IgG region unable to identify.Igenex Jan.09IFA titer 1:40 IND IgM neg pos 31 +++ 34 IND 39 IND 41 IND 83-93 + DX:Neuroborreliosis Posts: 5850 | From Kentucky | Registered: Dec 2008
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