Optimizing contact tracing for avian influenza in poultry flocks

Area of Science:

• Veterinary Epidemiology
• Infectious Disease Modeling

Background:

• Contact tracing is crucial for managing infectious diseases but is resource-intensive.
• Current methods rely on fixed time windows, often reducing efficiency.
• Highly pathogenic avian influenza (HPAI) causes significant economic damage in poultry.

Purpose of the Study:

• To estimate the precise timing of initial farm infections with HPAI.
• To improve the efficiency of contact tracing for HPAI outbreaks.
• To develop a tool for real-time support to policymakers.

Main Methods:

• A stochastic mechanistic model was fitted to daily mortality data from 63 infected poultry farms.
• Approximate Bayesian computation was used for parameter estimation.
• An online application was developed for real-time estimation.

Main Results:

• Estimated time of first infection ranged from 3.4 to 19.9 days prior to the last observation.
• Estimates were independent of poultry species and country.
• The developed application provides realistic date ranges for initial infections.

Conclusions:

• Accurate estimation of infection timing enhances contact tracing efficiency.
• The online tool supports policymakers in managing HPAI outbreaks.
• Improved contact tracing can mitigate the socio-economic impact of avian influenza.