Why is there concern about the H5N1 avian influenza, or “bird flu,” outbreak in Asia and other countries?
Although it is unpredictable when the next pandemic will occur and what strain may cause it, the continued and expanded spread of a highly dangerous avian H5N1 virus across eastern Asia and other countries represents a significant threat. Avian H5N1 influenza infection in humans was first recognized in 1997 when this virus infected 18 people in Hong Kong, causing 6 deaths. Concern has increased in recent years as avian H5N1 infections have killed large numbers of poultry flocks and other birds in Asia and Europe. Since 2003, more than 100 human H5N1 cases have been reported in Azerbaijan, Cambodia, China, Indonesia, Iraq, Thailand, Turkey, and Vietnam, and more than half of the victims have died.