A spatial transmission model for evaluating interventions during highly pathogenic avian influenza outbreaks

Epidemiological models are crucial tools for projecting future trends in infectious disease outbreaks and evaluating different control measures. A team from the 2026 WiLiMan-ID consortium developed a spatially explicit avian influenza transmission model to assess the effectiveness of various control strategies during a hypothetical avian influenza outbreak. The study found that the most effective control measures varied depending on the stage of the outbreak.

During the initial phase of the outbreak, when the number of available culling teams was limited, two different strategies resulted in similar numbers of premises with notified infections over the next 28 days. The first strategy involved fast reactive culling without preventive measures, while the second approach combined slower reactive culling with preventive culling efforts.

However, as more culling teams became available later in the outbreak, the strategy focusing on preventive culling proved to be significantly more effective in reducing the number of notified infected premises.

The researchers also demonstrated that the benefits or drawbacks of a particular strategy depend on the policy makers' objectives. Preventive culling can effectively limit transmission, but it comes at the cost of culling healthy poultry on premises that have not yet been infected. This trade-off between limiting transmission and the costs associated with intervention demonstrates the importance of carefully defining policy objectives and reassessing control measures at different stages of an outbreak to ensure their continued relevance and effectiveness.