THE NEED OF A GLOBAL TASK FORCE FOR INFLUENZA

摘要

Influenza A-viruses are divided into two distinct groups based on their ability tocause disease in birds: low pathogenic and highly pathogenic avian influenza (LPAI andHPAI). Only viruses of the H5 and H7 subtype have been shown to cause HPAI.Migratory birds are the reservoir of influenza A-viruses and are the source of LPAIviruses that may mutate into HPAI viruses in domestic poultry, causing severe diseaseoutbreaks with high mortality in these animals. Since 1997, it has become clear that avianinfluenza viruses may infect humans: in Hong Kong 18 people became infected with theHPAI H5N1 virus and 6 of them died. In 2003, a massive outbreak of HPAI amongstpoultry in The Netherlands, caused by a H7N7 virus, resulted in 89 clinical cases amongfarmers and poultry workers, one of which was fatal. The ancestors of this H7N7 virushad been found in migratory ducks prior to the outbreak. The virus had probably spilledover as a LPAI H7N7 virus to free-range chickens, in which it mutated to an HPAI virus.