Highly pathogenic avian influenza is an acute respiratory infectious disease caused by some viral strains of avian influenza virus A. Its severity is highly diverse ranging from common cold-like symptoms to septicemia, shock, multiple organ failure, Reye syndrome, pulmonary hemorrhage, and other complications leading to death. According to the laws, human infection of highly pathogenic avian influenza has been legally listed as class B infectious diseases in China. And it has been stipulated that it should be managed according to class A infectious diseases in China.