Constellation-based Classification of Avian Reovirus in Turkeys Reveals Shared Virus Origins Among Different Meat-type Farms

Cheng-Shun HsuehMichael A. Zeller^*Amro HashishOlufemi FasinaPablo PineyroOluwatobiloba AminuMohamed El-GazzarYuko Sato^*

• Iowa State University, Ames, United States

The US poultry industry suffers significant economic losses due to Avian Reovirus (ARV) infections, which mainly cause arthritis/tenosynovitis in turkeys and chickens. The emergence of outbreaks since 2012 highlights the urgent need for improved epidemiological tools. Given the distinct evolutionary history and limited resolution of existing typing methods for ARV, this study introduced a novel genotyping scheme to enhance source tracing and control strategies especially for ARV in turkeys. A dataset of 199 ARV sequences from turkey hosts was curated and organized based on branch distances from maximum likelihood phylogenetic trees using TreeCluster. The grouping performance was evaluated and optimized according to established criteria described in this study. As a result, a constellation-based genotyping approach was established, prioritizing the M2, S1 σC-encoding region, and L3 genomic segments due to their non-random reassortment and biological significance. The proposed scheme identified 8 major genotypes and revealed clear epidemiological links between turkey breeder and meat-type farms, as well as common shared sources among different meat-type farms, suggesting both vertical and horizontal transmission pathways. Additionally, reassortment events were detected using our novel typing scheme, highlighting the complex evolutionary dynamics of this segmented virus. By correlating genotypic patterns with epidemiological data, this study provides a foundation for improved ARV monitoring and disease management. These findings emphasize the need for and allows for the development of comprehensive genetic surveillance and offer valuable insights for controlling ARV outbreaks in the poultry industry, particularly turkey.