Following the last reported outbreaks of virulent Newcastle disease in New South Wales (reported in EMPRES Bulletin No. 10), the situation again deteriorated in December 1999. At least five new incidents were identified in the following three months and the virus was found as far as 300 km north of Sydney, in addition to its presence in the outskirts of Sydney. As was reported in EMPRES Bulletin No. 10, the outbreaks are caused by virulent mutants of an endemic Australian low-virulence virus; there is, however, no known connection between the farms. Recent research suggests that these virulent viruses have been present in the Australian poultry flock for longer than was originally thought, and a survey is being undertaken to determine the true prevalence and the distribution of the virus.
The Consultative Committee on Emergency Animal Diseases (CCEAD) has determined that this particular virus is non-eradicable in New South Wales in the short to medium term. Stamping out is no longer carried out but the flocks are still quarantined, and consultations between the government and the poultry industries are continuing to develop a long-term management strategy for dealing with the disease. The national plan, to be managed by the industry, will incorporate vaccination within a risk management context, in the absence of disease. There is still a commitment by the Agricultural and Resource Management Council of Australia and New Zealand (ARMCANZ) to a full stamping out programme in the event of an incursion of virulent Newcastle disease virus of exotic origin.
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