The virus is transmitted directly from possum to possum, probably through faeces and urine. It cannot be spread through the air. It is not possible to determine precisely how long wobbly possum disease has been present in New Zealand, because appropriate tests have not been available, but anecdotal evidence of possums acting strangely suggests may have been present in this country for many years. The Ministry of Agriculture will commission tests on historic possum samples stored in serum banks to try to determine how long it might have been here, but it is unlikely we will be able to establish this for certain. It is also unlikely that we will ever be able to determine how it may have come here.
Possums are New Zealand's number one introduced animal pest.
Not only do they destroy huge tracts of native bush, they are also be main vector for the spread of bovine tuberculosis in this country. The research into WPD was commissioned by MAF as part of this quest for new means to control possums. In Australia, they are a native animal and protected in most states and territories. The tests results from Germany provide an initial indication that the viruses which cause the two diseases are alike, and are related antigenetically. This means that the immune system sees them as similar.