The prevention and treatment of medical conditions forms the basis of health classes, and the debates over the cost, availability, and ethics of research and treatment recur frequently in events and critical thinking classes. This series provides material for these classes. This volume covers a common infectious disease that afflicts millions every year—the flu—but one that has the potential of being at the center of a new pandemic, similar to the one that killed millions during 1918. Influenza examines all aspects of this disease, including: • The influenza virus and how it leads to infection in humans. • The definition of epidemics and pandemics, and a description of the Influenza Pandemic of 1918. • The clinical signs and symptoms of influenza, and how it impacts special populations, such as the elderly and HIV-infected patients • The treatment and prevention of the flu The volume includes a glossary of important terms and a bibliography of accessible works that discuss the disease.