Background: Borreliosis is a tick-borne disease caused by bacteria of the genus Borrelia. Borreliosis can be caused by species of either the Borrelia burgdorferi sensu lato complex or relapsing fever Borrelia. Borreliosis is commonly caused by B. burgdorferi sensu stricto in North America, and is referred to as Lyme disease, B. afzelii in Europe and B. garinii in Eurasia. Although a Lyme-like illness has been reported in Australia no local Borrelia species has been identified in ticks, the most common vector. This study aimed to investigate the presence of Borrelia spp. in Australians diagnosed with a Lyme-like illness.
Method: Whole blood and serum samples from five study participants diagnosed with a Lyme-like illness were investigated by PCR and serology. Three participants were from New South Wales, and one each from Queensland and Western Australia. Nested PCR using primers directed against 16S rRNA gene were used to detect Borrelia DNA. Immunoblots (Euroimmun, Germany) using Borrelia whole cell sonicates or recombinant proteins were used to detect IgM and IgG antibodies against Borrelia.
Results: 16S rRNA amplicons (462bp) were sequenced and all were consistent with B. garinii. Immunoblot results detected IgG antibodies against at least one and up to three specific Borrelia antigens in all participants. Although the serology is suggestive of exposure to a Borrelia species it does not constitute a positive under Australian criteria.
Conclusions: Although there is evidence of IgG antibodies developed against specific Borrelia antigens in all study participants, none met the criteria for a positive Borrelia diagnostic immunoblot. PCR results detecting B. garinii would suggest a current or recent infection. All participants have a travel history and may have acquired the infection overseas. Further investigation targeting other genes of Borrelia will provide further insight.