H5N1 avian influenza virus expands its range.
D000818:Animals; D001208:Asia / Q000453:epidemiology; D001717:Birds; D004196:Disease Outbreaks / Q000662:veterinary*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000635:transmission; D011200:Poultry; D012426:Russia / Q000453:epidemiology