Lyme Borreliosis in Australia

Summary

Since the first clinical description of the Lyme syndrome in Australia in 1982, there have been continuing efforts, so far with little success, to demonstrate that a genuinely indigenous Lyme borreliosis exists in the country. Ixodes sp. ticks are abundant throughout coastal regions of the eastern seaboard and while they have been found to contain fastidious, slowly growing borreliae, none have proved so far to be B. burgdorferi. Neither has B. burgdorferi been isolated nor detected in humans or other vertebrates.

On the assumption that Lyme borreliosis in Australia will be similar to its northern hemisphere equivalent we are assembling a register of likely chronic, late stage LB patients. Representative clinical and serological data for five candidate patients are provided in this presentation. As well as excluding other likely causes of disease, we have tested these patients for evidence of antibody specific to the B. burgdorferi antigens 41 kDa (flagellin) 34 kDa (OspB) and 31 kDa (OspA) of each of the three strains B31, ACA-1 and NBS-16, using an immunoblotting technique. Two patients were antibody positive for all flagellin antigens, and for the OspA of ACA. We conclude that the illness experienced by these patients is highly likely to have been caused by exposure to astrain of B. burgdorferi that has antigenic epitopes in common with European rather than US strains. The antibody response of the remaining patients is varied, but all had antibody to the OspA antigen of at least one test strain; no reaction to OspB was detected.

These results persuade us that at least one, and perhaps several, types of B. burgdorferi are circulating in Australia. The exact nature of these agents awaits their successful isolation, in the meantime it may be possible by further immunoblotting, using a variety of other B. burgdorferi isolates, to develop an identikit image of the antigenie makeup of the cause of Australian LB.