Infectious agent: Variola virus
Description of illness: An infectious disease that spreads from direct and prolonged face-to-face contact and is spread by humans only. Symptoms vary based on stage of the disease progression and can include high fever, head and body aches, rash/sores on the tongue and mouth. Due to the success of vaccination efforts, smallpox was eradicated in 1980, with no known case of naturally occurring outbreaks since 1977. Since eradication, the vaccine is no longer required but the virus that causes smallpox can be used in biological attacks.