We isolated highly pathogenic avian influenza (HPAI) H5N5 and H5N1 viruses from crows in Hokkaido, Japan, during winter 2023-24. They shared genetic similarity with HPAI H5N5 viruses from northern Europe but differed from those in Asia. Continuous monitoring and rapid information sharing between countries are needed to prevent HPAI virus transmission.
Keywords: H5N1; H5N5; Japan; crows; highly pathogenic avian influenza virus; influenza; respiratory infections; subtype; viruses; zoonoses.