"While the suspected disease appears to affect only possums at this stage, we strongly recommend that people wear gloves if handling them," DOC Otago Conservancy animal pest ranger Bruce Kyle said today.
"It does not appear to have affected livestock or other wildlife, so it looks like a possum-specific disease at this stage."
Possums are probably one of the worst things to ever come to New Zealand. They destroy thousands of hectares worth of forest and like many introduced animals are also opportunistic predators of the indigenous wildlife, particularly our native birds. It's encouraging to see a new pathogen develop among these animals as a result, because it provides the promise of being able to drop possum numbers considerably and bring previously out of control populations to a manageable number.Of course, this really isn't something that should be surprising. When a population gets to a large enough number, there is a considerable selection pressure applied on numerous microbes to take advantage of the new 'ecology' that has opened up as a result. With possum densities as they are, such a new pathogen wouldn't find things to difficult to spread to new individuals and further selection for higher virulence would be the result. Both of these phenomena are already well established in human pathogens, for example emerging new viral diseases such as HIV and the dramatic increase in virulence of Vibrio cholerae after a water treatment plant broke down.
Overall with a bit of luck, this new organism will be able to ravage the possum population and bring numbers down to at least somewhat manageable levels.
