Epidemiology of an avian influenza outbreak in Victoria in 1985

In May 1985 an outbreak of avian influenza, a disease exotic to the Australian poultry industry, occurred on a farm in central Victoria. The outbreak was contained on that farm by immediate depopulation and disinfection measures. A description of the epidemiology of the outbreak was made during and after the event by interviewing involved personnel and by an extensive sampling and surveillance program both on the affected farm and across Victoria. Although the origin of the infection was not established, it is considered most likely that wild birds introduced the virus. The infection status of wild bird populations in the area has not been ascertained but sampling surveys of the poultry industry indicated that there were no other infected flocks in the state. The infection may have entered the affected flock as long as 2 weeks prior to the clinical outbreak although the exact timing could not be ascertained. The spread of disease on the farm appeared to be largely due to humans acting as mechanical vectors.