UK researchers have homed in on a human gene implicated in thwarting most bird flu viruses from infecting people. Bird flu chiefly spreads among wild birds such as ducks and gulls and can also infect farmed birds and domestic poultry such as chickens, turkeys and quails. Although the viruses largely affect birds, they can spill into bird predators, and in rare cases, humans typically in close contact with infected birds.
A human immune system protein called butyrophilin helps to stop bird flu from infecting people, but some viruses currently circulating have mutations that might overcome this barrier