ERADICATION OF CONTAGIOUS BOVINE PLEUROPNEUMONIA IN AUSTRALIA
Contagious bovine pleuropneumonia is a disease that only affects bovine animals that was first recognised in Germany in 1693, and it is a disease that most of today’s microbiologists will never have encountered. The causative organism is Mycoplasma mycoides subspecies mycoides. Susceptible cattle become infected by inhaling the droplets that are disseminated by the coughing of actively infected animals. The infected cattle may apparently recover, but approximately 25% will become carriers, and if stressed by adverse conditions will become highly infectious to any susceptible bovine host.
Pleuropneumonia first occurred in Australia in 1858, with the importation of five head of cattle from England, which included one infected heifer, onto a Victorian property This heifer died three weeks later, and the owner was advised he should destroy his entire herd – but the heifer had already infected a bullock team grazing on an adjoining property. Within a year the disease had spread rapidly via the overland road to New South Wales, and from there it spread into Queensland, across the north of Australia and later to Western Australia. Tasmania remained the only unaffected area of Australia. The worst affected area was in the north of Australia where in the 1930s 3 million cattle roamed over up to 5 million square kilometres which were mostly unfenced.
It took until 1973, using a modified test to screen cattle, that was developed in Alice Springs from the original standard test; and a cattle movement system developed by the Northern Territory Chief Veterinary Officer who had been an Army colonel using his military knowledge, to eradicate the damage done by one imported animal.