This page features videos on the clinical progression of Australian bat lyssavirus in a bat – November 2020, as well as atypical scrapie in sheep.
Lyssavirus in a bat
In November 2020, a little red flying fox was rescued after falling into a bush in the Port Douglas region. Clinical progression over 16 hours was documented in a series of videos. These videos are thought to be the only visual records of the progression of disease due to naturally acquired Australian bat lyssavirus (ABLV) infection in a bat.
A short report on the detection of ABLV in this bat has been published in the Feature section of Animal Health Surveillance Quarterly Vol 25. Issue 4. Page 7.
ABLV-infection is endemic in Australian flying foxes and causes an invariably fatal encephalitis. Clinical infection is associated with a wide range of central nervous system signs that usually progress rapidly to death (or euthanasia). The clinical signs and progression in this bat are typical of ABLV infection in bats.
Incidence of Australian bat lyssavirus in Queensland
The short story about this bat is in the Queensland section of the State and Territory Report AHSQ 22(4) (page 13 of the state and territory report file, page 29 on the full PDF)
The full published scientific paper about this incident is at Barrett. J. et.al (2020). An unprecedented cluster of Australian bat lyssavirus in Pteropus conspicillatusindicates pre-flight flying fox pups are at risk of mass infection. Zoonoses and Public Health. 67(4), 435-442. https://doi.org/10.1111/zph.12703
Douglas pup 3 on day 18 in care, demonstrating unusual movement of the tongue and mouth and paresis of the wing, which is not being held in the normal ‘wrapped’ position.
Video: Alicia Knudsen
Atypical scrapie
These videos are thought to be the only visual records of clinical atypical scrapie in Australian sheep.
A short report on the detection of atypical scrapie in these two Australian sheep is in the Feature section of Animal Health Surveillance Quarterly Vol 25. Issue 4. Page 4.
July 2020 – Video (13 secs) of clinical signs of atypical scrapie in a five-and-a-half-year-old merino ewe at a property in the Flinders region, Queensland, Australia. Clinical signs include overt ataxia with a wide-based stance, swaying from side to side, circling to the right, and an inability to circle to the left without tripping over and falling into the fence. The wool is in good condition with no wool damage to suggest rubbing or ‘scraping’.
August 2020 – Video (1 minute) of clinical signs of atypical scrapie in a seven year old merino ewe at a property in the Western Downs, Queensland, Australia. Clinical signs include incessant circling to the right, being in light condition (in comparison to cohort not shown video) and failing to escape via on open gate.
Australia is free of classical scrapie, with many controls in place to prevent its entry and the National Transmissible Spongiform Encephalopathy Surveillance Project (NTSESP) to detect it in the unlikely event that it should occur.
Detection of atypical scrapie in sheep does not change Australia’s favourable, OIE recognised, trade status and demonstrates that the NTSESP is effective.