Photograph of Major Walter Reed en route to Cuba. 1900. Courtesy of Historical Collections and Services, The Claude Moore Health Sciences Library, University of Virginia.

Walter Reed earned his medical degree from the University of Virginia in 1869 at the age of eighteen. Several years later he joined the Army Medical Corps, served as surgeon at frontier outposts and did post-graduate study in the new science of bacteriology. When malaria struck U.S. troops in Cuba, Reed, who had investigated an outbreak near Washington in 1895, was appointed head of the Army Yellow Fever Commission.

Photograph of Dr. Henry Rose Carter. No date. Courtesy of Historical Collections and Services, The Claude Moore Health Sciences Library, University of Virginia.

At the time, yellow fever was believed to spread by contact with an infected person or his possessions. In 1900 alumnus Henry Rose Carter, a quarantine officer with the U.S. Marine Hospital Service, published an article demonstrating an incubation period that pointed to a host carrier. Reed was skeptical of the popular theory and Carter's work helped convince him to focus on the mosquito as a possible transmitter. In a series of controlled experiments, including one involving future student John J. Moran, Reed and his colleagues proved that the disease was spread by mosquito bites and not by contact with infected clothes and beddin

Photograph of Lt. Col. Jefferson Randolph Kean. No date. Courtesy of Historical Collections and Services, The Claude Moore Health Sciences Library, University of Virginia.

Reed returned to Washington, and another alumnus, Major Jefferson Randolph Kean, chief sanitary officer of Havana, launched a massive mosquito eradication campaign, covering stagnant bodies of water with oil, screening drinking water barrels, and fumigating the houses of victims. The measures were successful immediately. In 1901 cases dropped precipitously from 1400 in Havana alone to 37 throughout Cuba. In 1902 no cases were reported.