Arch Virol (1999) 144: 135–145
Sequence analysis of rabbit haemorrhagic disease virus (RHDV)
in Australia: alterations after its release
, J. R. E. Hardy
, and B. D. Cooke
The University of Adelaide, Department of Crop Protection, Waite Campus,
Glen Osmond, Australia
CSIRO, Division of Wildlife and Ecology, Lyneham, Australia
Accepted June 26, 1998
Summary. Liver samples from rabbits killed by RHDV, collected from ﬁve States
in Australia in 1996 and 1997 were analysed by RT-PCR. A 398 bp fragment of
the capsid protein (VP60) gene was ampliﬁed by PCR and directly sequenced.
The alignment of the nucleotide and amino acid sequences and their comparison
with the original strain of the virus released in Australia indicated genetic changes
after two years have been small with 98.2% to 100% identity. The constructed
phylogenetic tree suggests slight differences in nucleotide substitutions in various
States but there is no clear evidence of clustering of sequences according to their
geographic origin. In practical terms, sequencing of viral RNA provides a means
of testing the efﬁcacy of further releases and subsequent spread of the virus if
such a strategy is employed as a means of enhancing RHD as a biological control
of the wild rabbit in Australia.
Rabbit haemorrhagic disease virus (RHDV) which belongs to the family Cali-
civiridae causes disseminated intravascular coagulation resulting in severe mor-
tality in European rabbits (Oryctolagus cuniculus L.) [5, 7]. The virus was origi-
nally reported in China  then spread to Europe . The virus is characterised
by having an icosahedral, non-enveloped nucleocapsid displaying cup-shaped
depressions on the surface and a major capsid protein of about 60 kDa in size
(VP60) [15, 16]. The genome of the virus consists of a positive single-stranded
RNA molecule of 7437 nucleotides and a subgenomic RNA of approximately
2.2 kb RNA which codes for VP60 [9, 10].
Present address: School of Biological Sciences, Flinders University, Adelaide, Australia.