A型流感病毒的自然感染已在多种动物有所报道 ,包括人、猪、马、海洋哺乳动物和鸟类等动物。这种破坏性传染病有时发生于人类。尽管从哺乳动物中只分离到较少的HA和NA亚型组合病毒 ,但是在鸟类中分离到了大部分HA和NA亚型组合。 Natural infections with influenza A viruses have been reported in many animals, including animals such as humans, pigs, horses, marine mammals and birds. This devastating disease sometimes occurs in humans. Although only a few combinations of HA and NA subtypes were isolated from mammals, most combinations of HA and NA subtypes were isolated in birds.