title: Searching for Lyme borreliosis in Australia: results of a canine sentinel study.
abstract: BACKGROUND
  Lyme borreliosis is a common tick-borne disease of the northern hemisphere that is caused by bacterial spirochaetes of the Borrelia burgdorferi (sensu lato) (Bbsl) complex. To date, there has been no convincing evidence for locally-acquired Lyme borreliosis on the Australian continent and there is currently a national debate concerning the nature and distributions of zoonotic tick-transmitted infectious disease in Australia. In studies conducted in Europe and the United States, dogs have been used as sentinels for tick-associated illness in people since they readily contact ticks that may harbour zoonotic pathogens. Applying this principle, we used a combination of serological assays to test dogs living in tick 'hot spots' and exposed to the Australian paralysis tick, Ixodes holocyclus, for evidence of exposure to B. burgdorferi (s.l.) antigens and other vector-borne pathogens.
  
  
  RESULTS
  Altogether, 555 dogs from four demographic groups were recruited into this study. One dog had evidence of exposure to Anaplasma spp. but no other dog was positive in screening tests. A total of 122 dogs (22.0%) had a kinetic ELISA (KELA) unit value > 100, and one dog with a high titre (399.9 KELA units) had been vaccinated against B. burgdorferi (sensu stricto) before travelling to Australia. Older dogs and those with a history of tick paralysis were significantly more likely to have a KELA unit value > 100. Line immunoassay analysis revealed moderate-to-weak (equivocal) bands in 27 (4.9%) dogs.
  
  
  CONCLUSIONS
  Except for a single dog presumed to have been exposed to Anaplasma platys, infection with Anaplasma spp. B. burgdorferi (s.l.), Ehrlichia spp., and Dirofilaria immitis, was not detected in the cohort of Australian dogs evaluated in this study. These results provide further evidence that Lyme borreliosis does not exist in Australia but that cross-reacting antibodies (false positive results) are common and may be caused by the transmission of other tick-associated organisms.
authors.affiliation: Vector and Water-Borne Pathogen Research Group, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia. P.Irwin@murdoch.edu.au.|College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia. P.Irwin@murdoch.edu.au.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Irwin
authors.affiliation: College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Robertson
authors.affiliation: Sydney School of Veterinary Science, University of Sydney, Sydney, New South Wales, 2006, Australia.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Westman
authors.affiliation: Pymble Veterinary Clinic, Philip Mall, Kendall Street, West Pymble, New South Wales, 2073, Australia.
authors.forename: Martine
authors.initials: M
authors.lastname: Perkins
authors.affiliation: Department of Infectious Diseases and Zoonoses, Bacteriology and Mycology, Ludwig-Maximilians-University Munich, 80539, Munich, Germany.
authors.forename: Reinhard K
authors.initials: RK
authors.lastname: Straubinger
mesh_terms: D000709:Anaplasma / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001315:Australia / Q000453:epidemiology; D025065:Borrelia burgdorferi / Q000276:immunology / Q000302:isolation & purification; D004283:Dog Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D004285:Dogs; D004536:Ehrlichia / Q000276:immunology; D016873:Ehrlichiosis / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay; D018884:Ixodes / Q000382:microbiology; D008193:Lyme Disease / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D000072739:Sentinel Species / Q000276:immunology / Q000382:microbiology* / Q000469:parasitology*; D012698:Serologic Tests; D017282:Tick-Borne Diseases / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D000907:Antibodies, Bacterial
keywords: Anaplasma; Australia; Borrelia burgdorferi (s.l.); Canine sentinel; Ehrlichia; Ixodes; Lyme borreliosis; Serology; Ticks; Vector-borne disease