Atypical Pathogenicity of Avian Influenza (H3N1) Virus Involved in Outbreak, Belgium, 2019, Steensels, Mieke, Lagacé-Wiens Philippe, Van Borm Steven, van den Berg Thierry, Corrigan Tim, Roupie Virginie, Rauw Fabienne, and Lambrecht Bénédicte , Emerging Infectious Diseases, 08/2020, Volume 26, Issue 8, (2020)