The flu is nothing to sneeze at. Up to 500,000 people die of influenza each year--36,000 in the United States alone. Throughout history, flu epidemics have killed more people than the plague or smallpox, making the flu the most deadly disease known to humanity. This book provides information about the flu, how it spreads, and how it is prevented and treated. Past flu epidemics are described, and a look into the future examines the potential of a bird flu epidemic as well as promising new research.