Responding to avian influenza in poultry farms in Victoria, Australia.

Objective: To describe a multi-agency public response to an outbreak of avian influenza virus in poultry farms in Victoria, Australia, in 2024. Methods: After detecting an outbreak of high-pathogenicity avian influenza at a poultry farm and notifying the Victorian health department, Agriculture Victoria identified a further seven infected premises through tracing and surveillance activities. Testing at the Australian Centre for Disease Preparedness identified high-pathogenicity H7N3 at seven premises in the Golden Plains Shire, and high-pathogenicity H7N9 at a property in the Terang region in the Corangamite Shire. The Victorian health department established a multi-agency incident management team, and we defined, identified and managed contacts and suspected cases. Public health actions included influenza vaccination, antiviral prophylaxis, active surveillance of high-risk contacts, and supporting infection prevention and control measures. Findings: We identified a total of 212 (165 high- and 47 low-risk) unique human contacts with residence locations spread across 25 local government areas. We identified 20 suspected cases from six of the eight infected premises, all of whom tested negative for influenza A. Of the 172 unique high-risk contacts and suspected cases, local health services and clinics reported that 19.2% (33) received antiviral medication and 27.3% (47) received the seasonal influenza vaccine. Conclusion: Our rapid, coordinated, multi-agency response was a success; however, governments, agricultural industries and health workers must strengthen preparedness and response strategies across national, state, regional and local levels to improve surveillance, foster collaboration and address gaps in preventive health care.