First Record of Ixodes affinis Tick Infected with Borrelia burgdorferi SL Collected from a Migratory Songbird in Canada

[Sproetje]

First Record of Ixodes affinis Tick (Acari: Ixodidae) Infected with Borrelia burgdorferi Sensu Lato Collected from a Migratory Songbird in Canada

Door: John D Scott, Kerry L Clark, Janet E Foley, Lance A Durden, Jodi M Manord and Morgan L Smith
Online: June 30, 2016
Uit: Journal of Bacteriology & Parasitology

http://www.omicsonline.org/open-access/ ... ?aid=76455

Introduction

Ixodes affinis Neumann (Acari: Ixodida: Ixodidae) is an obligate, blood-sucking ectoparasite that feeds on mammals and birds [1,2]. Biogeographically, this ixodid (hard-bodied) tick is native to Central and South America [3], and occurs in the United States from Florida to Virginia [2,4,5]. In the coastal plains of the Mid-Atlantic and southeastern United States, I. affinis parasitizes a wide array of mammals, including cotton mouse, Peromyscus gossypinus (LeConte); cotton rat, Sigmodon hispidus Say and Ord; marsh rice rat, Oryzmys palustris Harlan; southern short-tailed shrew, Blarina carolinensis (Bachman); gray squirrel, Sciurus carolinensis Gmelin; eastern cottontail, Sylvilagus floridanus (J.A. Allen); raccoon, Procyon lotor (Linnaeus); Virginia opossum , Didelphis virginiana (Kerr); domestic cat, Felis catus (L.); dog, Canis lupus familiaris L.; bobcat, Lynx rufus (Schreber); cougar, Puma concolor (L.); white-tailed deer, Odocoileus virginianus Zimmermann; and American black bear, Ursus americanus (Pallus) [2]. In particular, the cotton mouse and the cotton rat are major reservoir hosts for Borrelia burgdorferi sensu lato (s.l.) Johnson, Schmid, Hyde, Steigerwalt & Brenner in the southeastern United States [6]. Of biological and medical significance, I. affinis enhances the epidemiological cycle of B. burgdorferi s.l., especially within indigenous areas [7].

Songbirds (Passeriformes) are avian hosts of I. affinis and I. scapularis larvae and nymphs [1,5,8]. While en route to their breeding grounds, passerine migrants make landfall at Lyme disease endemic areas, and are often parasitized by host-seeking ticks. Since peak questing activity of I. scapularis and I. affinis nymphs coincides with peak northward songbird migration, ground-frequenting passerines are often parasitized by both of these nymphal species. In Canada, Scott et al. [8] reported I. affinis and I. scapularis on a Swainson's Thrush, Catharus ustulatus (Nuttall), in south-central Manitoba during northward spring migration. In a recent study, Heller et al. [5] reported I. affinis immatures on 6 different passerine species in southeastern Virginia, and one songbird-derived nymph was infected with B. burgdorferi s.l.

Based on tick-host-pathogen studies in the southeastern United States, researchers found that I. affinis is a competent vector of the Lyme disease bacterium, B. burgdorferi s.l. [6,7]. Globally, the B. burgdorferi s.l. complex consists of at least 23 genospecies or genomospecies. In North America, at least nine B. burgdorferi s.l. genospecies are present, namely B. americana , B. andersonii , B. bissettii , B. burgdorferi sensu stricto (s.s.), B. californiensis, B. carolinensis , B. garinii , B. kurtenbachii , and B. mayonii [9-16]. Of these genospecies, B. americana , B. andersonii , B. bissettii , B. burgdorferi s.s., B. garinii , and B. mayonii are known to be pathogenic to humans [16-20].

The aim of the present study was to expound on the movement of songbird-transported ticks in the Northern Hemisphere during northward spring migration, and report any novel tick-host associations in Canada. In addition, we wanted to determine whether any ticks on Neotropical and southern temperate songbirds are infected with B. burgdorferi s.l.

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In conclusion, we provide compelling proof that migratory songbirds transport I. affinis into Canada during northward spring migration. We document the first record of a B. burgdorferi s.s.- positive I. affinis in Canada and, synchronously, provide new host and distribution records for this tick species. Furthermore, we provide new evidence that I. affinis can be added to the list of competent enzootic vectors of B. burgdorferi s.l. in Canada. After I. affinis immatures are dispersed in Canada, they can moult during the summer and, if infected, transmit Lyme disease spirochetes to suitable vertebrate hosts. Additionally, I. scapularis immatures can act as a bridge vector to people and certain domestic animals. It is an inescapable fact that migratory songbirds are transporting ticks into Canada during northward spring migration, and some of these engorged ticks are infected with B. burgdorferi s.s., which is pathogenic to humans and certain domestic animals. Ultimately, it is firmly established that people do not have to frequent an endemic area to contract Lyme disease. Medical professionals, veterinarians, biomedical scientists, and public health officials should be vigilant that diverse variants of B. burgdorferi s.l. are introduced by songbird-transported Ixodes ticks, and pose a country-wide public health risk.

[Sproetje]

Een onderzoek uit 2005

Door: Morshed MG1, Scott JD, Fernando K, Beati L, Mazerolle DF, Geddes G, Durden LA.

Migratory songbirds disperse ticks across Canada, and first isolation of the Lyme disease spirochete, Borrelia burgdorferi, from the avian tick, Ixodes auritulus.

Abstract

During a 3-yr comprehensive study, 196 ixodid ticks (9 species) were collected from 89 passerine birds (32 species) from 25 localities across Canada to determine the distribution of avian-associated tick species and endogenous Lyme disease spirochetes, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt, and Brenner. We report the following first records of tick parasitism on avian hosts: the rabbit-associated tick, Ixodes dentatus Marx, from Manitoba and Ontario; the mouse tick, Ixodes muris Bishopp and Smith, from British Columbia; and the blacklegged tick, Ixodes scapularis Say, from New Brunswick. Moreover, we provide the first record of the Neotropical tick, Amblyomma humerale Koch (1 nymph), in Canada and its parasitism of any bird. This tick was compared morphologically with nymphs of other Neotropical Amblyomma spp., and genetically, using a 344-bp fragment of the 12S rDNA sequence of 41 New World Amblyomma species. The first collections of the western blacklegged tick, Ixodes pacificus Cooley and Kohls, from passerine species in Alberta and British Columbia, are also reported. Notably, we further report the first isolation of B. burgdorferi from the bird tick, Ixodes auritulus Neumann, collected from an American robin, Turdus migratorius L., on Vancouver Island. Furthermore, B. burgdorferi-positive I. auritulus larvae were collected from a reservoir-competent fox sparrow, Passerella iliaca (Merrem). Our findings indicate that ground-dwelling passerines, in particular, are parasitized by certain ixodid ticks and play an important role across Canada in the wide dispersal of B. burgdorferi-infected ticks and increased risk of Lyme disease exposure.