The age-old chess game of host and disease, continually evolving, has changed radically in our time. The basic cause lies in our destruction of remote ecosystems, thereby unleashing new viruses. With our own bodies widely available to them, these new infectious organisms can easily traverse the "global village". AIDS, breast cancer, cholera, malaria, asthma, and even re-emergent tuberculosis threaten us. Virulent new microbes are taking hold, despite our best drugs and, sometimes, even because of them. Conventionally treated as if static, our microscopic enemies are in fact capable of mutation and rapid change. Flourishing as world population expands, they often evolve beyond the reach of current antibiotics. Originally published as Evolutionary Medicine, this new paperback edition issues a warning to the medical establishment. Breakout shows the potential threat of emerging viruses and drug-resistant bacteria and suggests public health strategies for countering them.