Medical News & Perspectives.

Discusses the pandemic threat posed by avian influenza in Hong Kong, China. How the virus jumped species; Destruction of four million chickens due to a detection of the influenza virus in Hong Kong poultry; Conditions for nonoccupational exposure; Consideration of the outbreak in 1997; Characteristics of surveillance measures on the borders; Views about the pandemic from Nancy Cox, the chief of the influenza branch of the National Center for Infectious Diseases at the U.S. Centers for Disease Control and Prevention.