Assessing the risk of highly pathogenic avian influenza (HPAI) spread associated with the permitted movement of duck hatching eggs out of or within control areas in the United States

In the United States (U.S.), permitted continuity of business (COB) movements are key to safely moving at-risk but uninfected poultry and poultry products out of or within highly pathogenic avian influenza (HPAI) control areas (CAs) (i.e., 10km areas established around infected premises). Presently, most state animal health agencies use the Secure Poultry Supply (SPS) to guide permitted product movements which provides heightened biosecurity practices and surveillance derived from science-based risk assessments. There is currently SPS guidance available for egg laying, broiler, turkey, and upland game bird live bird and product movements, and, in 2023, efforts to conduct risk assessments focused on movements of duck-specific products began. Using a framework adapted from the World Organisation for Animal Health’s Import Risk Analysis methods, the risk of duck hatching eggs moving out of or within an HPAI CA spreading virus to other poultry premises was evaluated. Disease pathways including the likelihood of duck eggs becoming contaminated before movement and the likelihood of day-old ducklings at a hatchery becoming infected were systematically evaluated using input from a public-private duck sector workgroup and information from peer-reviewed literature related to host-virus-environment interactions. Additionally, within-barn HPAI transmission and active surveillance simulation models were built to evaluate surveillance protocols for monitored duck breeder flocks. Models were parameterized using mortality data from U.S. duck companies and scientific literature describing the pathogenicity of H5 clade 2.3.4.4 HPAI viruses in ducks. Here, we discuss risk assessment results as well as challenges in developing HPAI transmission simulation models for ducks.

Kaitlyn St. CharlesSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Sylvia Wanzala-MartinSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Peter BonneySecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Amos SsematimbaSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Department of Mathematics, Faculty of Science, Gulu University, P.O. Box 166, Gulu, UgandaRosemary MarusakSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Mickey LeonardSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Marie CulhaneSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108Carol CardonaSecure Food Systems Team, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108

Biosecurity, mitigation, control, and post-epidemic considerations in poultry