Walter Reed (1851-1902), American military surgeon and head of the U.S. Army Yellow Fever Commission, is widely known as the man who conquered yellow fever by tracing its origin to a particular mosquito species.

Walter Reed was born on Sept. 13, 1851, at Belroi, Va., the son of a Methodist minister. After attending private schools, Reed entered the University of Virginia, where he received his medical degree in 1869, after completing only 2 years. He then went to New York, where he received a second medical degree from the Bellevue Hospital Medical College in 1870. After working for the Board of Health of New York and of Brooklyn, Reed was commissioned an assistant surgeon in the U.S. Army with the rank of first lieutenant in June 1875. Then followed 11 years of frontier garrison duty, further study at Johns Hopkins Hospital while on duty in Baltimore, and an assignment as professor of bacteriology and clinical microscopy at the newly organized Army Medical School in Washington in 1893.

When yellow fever made its appearance among American troops in Havana, Cuba, in 1900, Reed was appointed head of the commission of U.S. Army medical officers to investigate the cause and mode of transmission. After some months of fruitless work in searching for the cause of the disease, Reed and his associates decided to concentrate upon determining the mode of transmission. Carlos Juan Finlay first advanced the theory that yellow fever was transmitted by mosquitoes (he blamed it on the Stegomyia fasciata, later known as the Aedes aegypti) and proved it by experiments, but physicians generally did not credit the possibility. Walter Reed confirmed Finlay's findings by using human subjects. In fact, there was no alternative to experimentation with humans; Reed and his associates argued persuasively that the results would justify the procedure. Mosquitoes that had been fed on yellow fever-infected blood were applied to several of Reed's associates, including Dr. James Carroll, who developed the first experimental case of the disease.

Then followed a series of controlled experiments with soldier volunteers. In all, 22 cases of experimental yellow fever were produced: 14 by mosquito bites, 6 by injections of blood, and 2 by injections of filtered blood serum. At the same time, in order to eliminate the possibility of transmission by contact, Dr. Robert P. Cook and a group of soldiers slept in a detached building in close contact with the clothing and bedding of yellow fever patients from the camp hospital. Since no case of illness resulted from any of these contacts, the theory was conclusively proved.

The value of the commission's work quickly became evident. In 1900 there had been 1,400 cases of yellow fever in Havana; by 1902, after the attack, mounted because of the commission's report, on the mosquito had been under way for over a year in Cuba and the Panama Canal Zone, there was not a single case. Now that its mode of transmission is known, there is no danger of yellow fever in any country with adequate control facilities.

Reed returned to Washington, D.C., in February 1901 and resumed his teaching duties at the Army Medical School. In 1902 Harvard University and the University of Michigan gave him honorary degrees. Only a few days before his death in Washington on Nov. 22, 1902, he was appointed librarian of the Army Medical Library. The Walter Reed Hospital in Washington was named in his honor.

Further Reading

• Howard A. Kelly, Walter Reed and Yellow Fever (1906; 3d ed. rev. 1923), includes a bibliography of Reed's writings. See also Albert E. Truby, Memoir of Walter Reed: The Yellow Fever Episode (1943).
• Bean, William Bennett, Walter Reed: a biography, Charlottesville: University Press of Virginia, 1982.