In 1969, modern drugs and powerful vaccines prompted U.S. Surgeon General W.H. Stewart to declare it was time to “close the books on infectious diseases.” Now, the director of the U.S. Centers for Disease Control and Prevention says the proclamation was hasty.

David Satcher, speaking at Eastern Virginia Medical School Tuesday, said his agency and the medical community in general must refocus their efforts to combat a growing number of viruses and bacteria.