Birds act as a reservoir for the virus, meaning the virus can replicate at high enough levels to cause significant viremia, or elevated viral blood counts, which allows for transmission to other uninfected mosquitoes.

鸟类是此病毒的宿主，意味着病毒可在其体内以较高的水平复制，以至于导致病毒血症，继而传播给其它未受感染的蚊子。