Yellow fever is the name given to a disease that is caused by the yellow fever virus. The virus is a member of the flavivirus group. The name of the disease is derived from the appearance of those infected, who usually present a jaundiced appearance (yellow-tinted skin).

The agent of infection of yellow fever is the mosquito. The agent was first identified in 1900 when the United States Army Yellow Fever Commission (also referred to as the Reed Commission after its leader, Walter Reed) proved that the mosquito species Aedes aegypti was responsible for spreading the disease. Until then, yellow fever was regarded as requiring direct person-to-person contact or contact with a contaminated object.

The disease has caused large outbreaks involving many people in North America, South America, and Africa, stretching back at least to the 1700s. At that time the disease was often fatal. The availability...