Australian bat lyssavirus is a species of lyssavirus endemic to bats in Australia that causes fatal rabies-like encephalitis in bats, humans and other mammals.
Explanation
Australian bat lyssavirus (ABLV) belongs to the genus Lyssavirus within the family Rhabdoviridae. It was first identified in 1996 after a sick black flying fox (Pteropus alecto) and a yellow-bellied sheath-tailed bat (Saccolaimus flaviventris) were found to be infected. Like other lyssaviruses, ABLV is an enveloped virus with a negative-sense single-stranded RNA genome of about 12 kilobases encoding the nucleoprotein, phosphoprotein, matrix protein, glycoprotein and RNA-dependent RNA polymerase. Phylogenetically, ABLV is closely related to classic rabies virus and clusters within phylogroup I lyssaviruses. Distinct genetic variants are associated with frugivorous bats (flying foxes) and insectivorous bats, indicating multiple maintenance cycles. Surveillance studies have detected viral RNA and antibodies in flying fox populations throughout eastern and northern Australia, with prevalence usually below 1 %, suggesting enzootic circulation. The virus replicates in neural tissue and is shed in saliva, enabling transmission through bites or scratches. Experimental infection of mice and cell cultures shows that the virus is neutralised by antibodies raised against current rabies vaccines, supporting the use of standard rabies vaccines and immunoglobulin for prophylaxis.
Human and Animal Cases
Three human infections with ABLV have been documented. In 1996 a wildlife carer contracted the virus after being bitten by a flying fox and developed fatal encephalitis; a similar case occurred in 1998. The most recent fatality was reported in 2013 when an eight‑year‑old child was scratched by an infected bat. Spillover infections have also been recorded in horses; outbreaks in 2013 and 2015 resulted in several equine deaths and required quarantine measures. ABLV has been detected in at least one dog in Australia. Public health authorities recommend that people avoid handling bats unless trained and vaccinated. Bat carers and veterinarians working with bats should receive pre‑exposure rabies vaccination. Following any bat bite or scratch, immediate wound cleansing and post‑exposure prophylaxis with rabies vaccine and human rabies immunoglobulin are advised. ABLV is a rare but deadly lyssavirus maintained in Australian bat populations. Although human cases are uncommon, the outcome is invariably fatal without prompt prophylaxis. Education, vaccination of high‑risk groups and strict adherence to post‑exposure protocols are essential to prevent transmission. Related Terms: Rabies virus, European Bat Lyssavirus 1, European Bat Lyssavirus 2, Duvenhage virus, Lagos bat virus