Heterogeneous Permissiveness of Chicken Cells and Tissues to Oropouche Viruses

Massive outbreaks of a reassortant Oropouche virus (OROV) spread across Latin America and the Caribbean in 2023-2025. OROV is a reemerging arbovirus belonging to the trisegmented RNA peribunyavirus family. Viral transmission occurs in sylvatic and urban cycles involving humans and other vertebrates with Culicoides biting midges as the main vector in urban settings. Anti-OROV antibodies have been found in domestic and wild birds in Brazilian OROV-endemic areas. However, no studies exist on the permissiveness of OROV in avian models, and the contribution of birds to the OROV spread remains largely unexplored. Our research indicates that chicken embryonic fibroblasts and chicken tissue explants from the liver, heart, and lung are selectively infected by OROV strains isolated by our group in South America, including the novel OROV reassortant. This work contributes to the development of avian models to investigate new determinants in the infection and transmission of an important arbovirus in the Americas.