Calicivirus infected dead hare found in the nature reserve east of The Fair (W.Pix)
On the 10 April Friends of Mt Majura volunteer Waltraud Pix found a dead European brown hare in the nature reserve east of The Fair, North Watson (Canberra Nature Map at https://canberra.naturemapr.org/Community/Sighting/3394564). The animal had no external injuries and showed the stretched limbs and head typical of animals killed by calicivirus and Waltraud submitted the animal to CSIRO for testing.
Robyn Hall, CSIRO, confirmed that the hare was positive for the recombinant variant of the caliciviros strain RHDV2, reported here (https://www.ncbi.nlm.nih.gov/pubmed/29226567 / https://www.biorxiv.org/content/early/2017/08/09/173930).
Robyn wrote
“…the rabbit caliciviruses used for biocontrol purposes in Australia (RHDV1 and RHDVa-K5) are specific for European rabbits (Oryctolagus cuniculus). However, the RHDV2 virus can also infect a number of hare species, including the European brown hare found in Australia.
So far, we have detected a limited number of hares (<10) infected with RHDV2 in Australia, although none previously from the ACT. However, we only rarely receive hare samples. The extent of RHDV2 infection in Australian hare populations is currently unknown. Hares are considered a pest animal in Australia.
The recombinant strain refers to a virus with the outer shell of RHDV2 and the inner virus machinery of an RHDVa virus. Because this virus has the outer shell of RHDV2 it behaves in very much the same way i.e. it can infect hares and young rabbit kittens whereas RHDV1 and RHDVa viruses can’t. This variant was first detected in NSW in 2016 and has since been detected in a number of rabbits and hares in NSW, the ACT, and Victoria (one case). It continues to be dominant in the local Canberra, Yass, Michelago, Carwoola area.”
CSIRO has completed further testing and can confirm this is the recombinant RHDV2 virus form as described above.
Waltraud 11 May 2018
