Infection Prevalence of Borrelia burgdorferi in Ticks Collected from Songbirds in Far-Western Canada
Worldwide, wild birds play a vital role
in the dispersal of ticks that harbour tick-borne pathogens, including Borrelia
burgdorferi, the Lyme disease bacterium. Passerine birds (order:
Passeriformes), commonly called songbirds, are hosts for certain hard-bodied
ticks (Ixodida: Ixodidae) that carry pathogenic microorganisms.
In this paper, the
authors aimed to determine: 1) the infection prevalence of B. burgdorferi in bird-feeding ticks and 2) pinpoint passerine
species that are most heavily involved in tick infestations and enzootic
maintenance of Lyme disease spirochetes. Ticks were
collected from wild-caught songbirds at various times.
Using PCR testing,
we found 124 (31%) of 405 ticks (4 species) to be infected with B. burgdorferi. Transstadial
transmission of B. burgdorferi occurred
from larva to nymph, plus nymph to adult, in the avian coastal tick, Ixodes
auritulus, collected from songbirds in British Columbia (B.C).
Collectively, all 3 motile life stages (larva, nymph, adult) of this tick had
an infection prevalence of 31% for B. burgdorferi,
which suggests vector competency. A Pacific Wren was highly infested with I. auritulus immatures, and
20 (44%) of 45 ticks (2 nymphs, 43 larvae) were infected with B. burgdorferi. This heavy
infestation shows the high potential to initiate a new population of ticks and
to disseminate Lyme spirochetes. Epidemiologically, B. burgdorferi-infected I. auritulus larvae collected from the Spotted
Towhee, Swainson’s Thrush, Pacific Wren, and Fox Sparrow suggested that these
avian hosts act as reservoirs for B. burgdorferi.
In conclusion,
resident and migratory songbirds are disseminators of borreliae. The present
study provides additional evidence to show that all 3 motile stages of I.
auritulus play a vital role in maintaining B.
burgdorferi in the environment along the Pacific Coast. Besides, because
songbirds widely disperse Lyme disease vector ticks, primary health providers
and the general public must be vigilant that outdoors people may be bitten by B. burgdorferi-infected
ticks throughout far-western Canada.
Article by John D. Scott, et al, from
Canada and USA.
Full access: http://t.cn/EVhwmB6
评论
发表评论