Introduction
Introduction
Modern medicine once appeared well on the road to conquering infectious diseases. Over the past half-century, the discovery of antibiotics and new vaccines has eradicated smallpox and greatly reduced the virulence of scourges of polio and other formerly common diseases. But more recently, mysterious, new outbreaks have humbled scientists and alarmed the world. The early 1980s saw the emergence of AIDS and its relentless transformation into a global killer. Now, more limited but equally lethal new diseases - among them Ebola hemorrhagic fever - are demonstrating the limits of modern medicine's control over infectious diseases. At the same time, drug-resistant strains of more familiar maladies, such as tuberculosis, pose a new generation of threats to public health.