Walter Reed was born in Virginia in 1851. In 1869, after a year of medical school, Reed graduated from the University of Virginia with a degree in medicine. He then studied at Bellevue Medical Hospital in New York. He joined the Army Medical Corps in 1875 and spent most of the next two decades at frontier posts, but did post-graduate education at Johns Hopkins and other places. In 1893, Reed began serving as curator of the Army Medical Museum and professor of bacteriology and clinical microscopy at the Army Medical School. As part of the Surgeon General's Office staff in Washington, Reed was assigned to investigate typhoid fever in 1898 and then yellow fever a year later.
Reed spent the war studying typhoid fever. In 1899 during the wake of the Spanish-American War, Reed and Dr. James Carroll (also of the Army Medical Museum) investigated the bacteria thought to cause the disease and concluded that it did not. In May 1900, Reed headed the Yellow Fever Board, investigating the cause of the fever. The team, including Reed and Carroll also included Dr. Jesse Lazear and Cuban-born probably-immune Dr. Aristides Agramonte. The men who all knew each other convened at Columbia Barracks near Havana, Cuba. Their first accomplishment was to again rule out the recently-proposed bacterial theory. After a prison outbreak when one prisoner was infected and died but the eight other prisoners were not infected, Reed suggested a method of transmission by mosquitoes, which were already known to transmit malaria. Finlay was contacted and provided mosquitoes for testing and Dr. Lazear, who had previously worked with mosquitoes, began experiments in a lab at the Barracks with them while Reed returned to Washington to finish the Typhoid Board's report. Since no animals were known to get the fever, the Yellow Fever Board concluded that the ethical experiment would be to try to infect themselves. By having a mosquito bite them, Lazear successfully infected Dr. Carroll and a volunteer soldier named Pvt. William Dean in August. Lazear though may also have been testing himself for he was infected and died on September 25, 1900. He had reported being bitten by accident in Havana, but his notes implied he might have experimented on himself; Reed was not sure if Lazear was infected accidentally or purposefully, but accepted the accidental theory. Lazear's notebooks enabled Reed to study the data Lazear compiled when he returned from the States. Transmission by mosquito was obvious to the Board at that point and Reed reported that they were the cause in October - after 5 months of work, not a year as stated in the movie. The Washington Post called the hypothesis "the silliest beyond compare," but in November, Camp Lazear was established as a quarantine site to prove the theory beyond a doubt. Fourteen American soldiers volunteered and recent Spanish immigrants were hired using the first "informed consent" form. Private John Kissinger was the first to get the fever, and Charles Sontag, the last. No one in the experiment died, Spanish or American. Congress eventually authorized gold medals for the American volunteers. Using volunteers, the team also tested the fomite theory with articles fouled with the effusions from yellow fever victims including the dead men's clothes (although they were allowed to eat outside). This theory was proven wrong - "burst like a bubble" in Reed's words.
Reed realized that the Aedes aegypti mosquito (which has been renamed three times) carried yellow fever but only under certain conditions. The female mosquito must bite a yellow fever victim during the first three days of an attack, incubate the virus in its body for at least twelve days and then bite another person to pass on the disease. Reed's team was the first to prove the mechanics of infection of yellow fever. Since there was no cure or vaccine, soldiers continued to die from the disease, but Gorgas' mosquito control efforts meant by the summer of 1901, Havana was free of yellow fever. This discovery enabled the United States to essentially eradicate yellow fever within its borders after one last epidemic in New Orleans in 1905. In Panama, William Gorgas was able to suppress the disease so the Panama Canal could be built, although he was able to use methods such as oiling water so the mosquitoes suffocated. The disease proved easy to conquer because the Aedes aegypti mosquito is an urban mosquito and breeds only in small pools of stagnant water such as fish ponds or even flower jars. Although a vaccine was developed in the 1930s, yellow fever is still prevalent in tropical climes due to both a different mosquito vector and the fact that jungle yellow fever, as it is occasionally known, can live in monkeys as well as human hosts.
Reed died in 1902, of appendicitis, at Washington Barracks hospital, now on Fort McNair in the District. The hospital named in his honor opened in 1909, and the Museum he headed is open to the public on its grounds until the hospital closes and the Museum moves in 2011.