Detection of Zoonotic Arboviruses in Ruffed Grouse (Bonasa umbellus) in the Upper Midwest, USA, 2018-2022

Arthropod-borne viruses (arboviruses) are a taxonomically varied group of viruses that affect the health of many avian species, including the ruffed grouse (Bonasa umbellus), a popular upland game bird whose numbers are in decline in portions of its range. Hunter-harvested ruffed grouse tissue samples were tested for arboviruses during the 2018-2022 hunting seasons in Michigan, Minnesota, and Wisconsin, USA. A low percentage of harvested ruffed grouse were infected with West Nile virus (8/1892; 0.4%), eastern equine encephalitis virus (18/1892; 1.0%), and Highlands J virus (4/1892; 0.2%), and approximately half (16/30) of those infected had histologic cardiac lesions consistent with arboviral infection. Some ruffed grouse may be adversely affected following infection with these viruses, highlighting the need for increased awareness and continued surveillance, particularly in the face of additional stressors such as climate change, which may alter virus-vector-host dynamics, host susceptibility to arbovirus infections, and geographical distributions.