Abstract Title
Origin, spread, and interspecies transmission of dominant epidemic H9N2 avian influenza viruses with increased threat
Abstract
The H9N2 subtype of avian influenza viruses (AIVs) is widely prevalent in poultry and wild birds globally, with occasional transmission to humans. Among multiple lineages, the BJ/94 lineage of H9N2 has emerged as a significant public health concern in recent years; however, its evolutionary dynamics and transmission patterns remain poorly understood. In this study, we demonstrate that over a span of approximately 30 years (as of March 2023), the BJ/94 lineage H9N2 AIVs has undergone significant alterations in its geographical distribution, interspecies transmission dynamics, and viral reassortment patterns, thereby augmenting the associated public health risks. These changes primarily occurred through the emergence of its dominant genotype G57. In the initial decade, the G57 genotype emerged in East China via gene exchange between BJ/94 and G1 lineages. Subsequently, this genotype rapidly adapted to chickens and disseminated from East China to encompass the entire country (2002-2012). Since 2013, the G57 genotype virus expanded beyond China's borders into eight other countries while concurrently reassorting with multiple subtypes of AIVs to form multiple novel zoonotic reassortants. Chickens play a pivotal role in the generation and circulation of the G57 virus, with ducks and minor poultry likely assuming an increasingly significant role. China along with Vietnam have become hotspots for international dissemination of this genotype. Notably, the fact that this virus has spread to wild birds, mammals and humans suggests that the BJ/94 lineage H9N2 virus may further surpass geographical and species limitations, leading to more extensive and severe consequences.
Co-Author(s)
Yong Zhou,1,† Yudong Li,1,† Hongzhuang Chen,1 Sicheng Shu,1 Honglei Sun,1 Yipeng Sun,1 Jinhua Liu,1 Lu Lu,2,* and Juan Pu1,*
1National Key Laboratory of Veterinary Public Health and Safety, Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China; 2Roslin Institute, University of Edinburgh, Edinburgh, UK
†These authors contributed equally to this work
*Corresponding author: pujuan@cau.edu.cn; lu.lu@ed.ac.uk
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in poultry