A Federal health official said that the Earth may be on the brink of a world-wide epidemic from a bird flu virus.

The head of the Centers for Disease Control, Dr. Julie Gerberding, said that scientists expect the virus which has swept through chickens and other poultry in Asia will change into a flu that can be transmitted among humans.

The official said the virus may become as deadly and infectious as viruses that killed millions during three influenza epidemics of the 20th century.