II.

History

It is probable that the disease initially appeared in Africa and that it was brought to America at the time of the slave trade. The disease was first described in medical terms during the 17th century, when an outbreak was observed in the Yucatán Peninsula, Mexico. Ultimately yellow fever spread to the U.S., Spain, and other countries.

In 1881 the Cuban physician Carlos Finlay advanced the hypothesis that yellow fever is transmitted by mosquito bites. Finlay's theory was verified in 1901 by the work of several investigators, notably the American bacteriologist Walter Reed, who also proved the agent to be a virus. The disease was brought under control by advanced methods of sanitation, including drainage of mosquito breeding grounds and quarantine of ships arriving from infected areas.