Lyme Borreliosis is a common tick-borne disease of the northern hemisphere caused by the spirochaetes of the
Borrelia burgdorferi sensu lato (B. burgdorferi s. l.) complex. It results inmulti-organ diseasewith arthritic, cardiac,
neurological and dermatological manifestations. In the last twenty-five years there have been over 500 reports of
an Australian Lyme-like syndrome in the scientific literature. However, the diagnoses of LymeBorreliosis made in
these cases have been primarily by clinical presentation and laboratory results of tentative reliability and the true
cause of these illnesses remains unknown. A number of animals have been introduced to Australia that may act as
B. burgdorferi s. l. reservoirs in Lyme-endemic countries, and there are some Australian Ixodes spp. and
Haemaphysalis spp. ticks whose geographical distribution matches that of the Australian Lyme-like cases. Four
published studies have searched for Borrelia in Australian ticks, with contradicting results. The cause of the
potential Lyme-like disease in Australia remains to be defined. The evidence to date as to whether these illnesses
are caused by a Borrelia species, another tick borne pathogen or are due to a novel or unrelated aetiology is
summarised in this review.