concept for spread of h5n1 virus from birds to other animals showing a chicken and a cow's head on dark background

virus view transmitted transmission strain spreading spread side sickness sick showing safety research public pathology pathogenic pandemic outbreak microbiology medical livestock infectious infections infection infected hygiene health head h5ni h5n2 h5n1 generative food flu fever farm facing epidemic disease dark cows cow control contagion concept chicken birds bird biology background animals animal