Bovine tuberculosis - the New Zealand problem

Control strategies based on the slaughter of cattle identified as infected by skin testing have been successful in eradicating bovine tuberculosis from several countries. In contrast, identical control methods have not achieved eradication in New Zealand. The reason for the persistence of tuberculosis in New Zealand is the presence of a wildlife reservoir of infection. While possums are the principal wildlife reservoir of bovine tuberculosis, feral pigs and wild deer may also be a source of infection for domestic animals. Current control programmes in which possums are poisoned are successful in reducing but not eliminating the spread of infection to cattle and farmed deer. The development of vaccines and the biological control of possums is the focus of active research in New Zealand. These are long-term research projects that will take many years before they can be sufficiently developed to be used to eradicate bovine tuberculosis from this country.