Assessing the particle types involved in the airborne transmission of avian influenza virus and estimating the risk with optimized mathematical models.

Abstract

Since October 2021 Europe is experiencing the largest highly pathogenic avian influenza virus (HPAIV) epidemic so far, causing enormous losses of wild birds and poultry. Despite strict biosecurity measures, farms keep getting infected. Airborne transmission at the wild-domestic interface and between farms is one the routes that is thought to play a role in these introductions. Poultry farms emit large amounts of particulate matter (PM) into the environment that can serve as vectors for (HP)AIV (RNA). Moreover, airborne spread may impose a risk for public health, as some variants of the virus are zoonotic. Current risk assessment models predict risks based on particles with standard aerodynamic diameters, but behaviour of feather (material) and other organic material, and the viability of HPAIV associated with different particles is largely unknown. The aim of this project is to gain insight into the behaviour of and distribution of infectious virus over different particle types and to improve risk assessment models for airborne transmission. Model input parameters will be collected from the literature, laboratory, and field experiments. Current mathematical models will be adapted, parameterized with the collected data, and validated. This model will serve as a tool for policymakers and will allow for improved risk-based control measures to reduce opportunities of HPAIV to be transmitted from wild birds to poultry and vice versa, between poultry farms and to mammalian hosts, including humans.