Emerging tropical diseases in Australia. Part 3. Australian bat lyssavirus

Since its discovery in a juvenile black flying fox (Pteropus alecto) in 1996, Australian bat lyssavirus (ABLV) has become the cause of a potentially important emerging disease for health authorities in Australia, with two human deaths (one in 1996 and one in 1998) attributed to the virus in the north-eastern state of Queensland. In Australia, the virus has been isolated from all four species of flying fox found on the mainland (i.e. P. alecto, P. scapulatus, P. poliocephalus and P. conspicillatus) as well as a single species of insectivorous bat (Saccolaimus flaviventris). Australian bat lyssavirus belongs to the Lyssavirus genus and is closely related, genetically, to the type strain of Rabies virus (RABV). Clinically, patients infected with ABLV have displayed the 'classical' symptoms of rabies and a similar disease course. This similarity has led to the belief that the infection and dissemination of ABLV in the body follows the same pathways as those followed by RABV. Following the two ABLV-related deaths in Queensland, protocols based on the World Health Organization's guidelines for RABV prophylaxis were implemented and, presumably in consequence, no human infection with ABLV has been recorded since 1998. ABLV will, however, probably always have an important part to play in the health of Australians as the density of the human population in Australia and, consequently, the level of interaction between humans and flying foxes increase.