' Skip To Content
The Great Fever | Article

Jesse Lazear (1866-1900)

When Jesse Lazear died from yellow fever, he left a wife, a newborn child, and an infant. He also left a lasting contribution to the scientific understanding of the disease.

HSL University of Virginia

Path to Cuba
Born in Baltimore County in 1866, Lazear graduated from the city's Johns Hopkins University in 1889. Three years later, he earned his M.D. from Columbia University in New York. Aristides Agramonte, a classmate with whom he would serve on the U.S. Army Yellow Fever Board, called him "the type of the old southern gentleman, kind, affectionate, dignified, with a high sense of honor, a staunch friend and a faithful soldier." After studying abroad, Lazear married his wife Mabel in 1896. He joined the medical staff of Johns Hopkins Hospital, teaching and researching in the laboratory of clinical pathology. The work spurred him to further his study of malaria and yellow fever. He found the opportunity with the U.S. Army.

On Track of the "Real Germ"
With the title of acting assistant surgeon with the U.S. Army Medical Corps, Lazear reported for duty to Camp Columbia, Cuba, in February 1900. He proceeded to study the bacteriology of tropical diseases, particularly malaria and yellow fever. In May, a new board was created to study such diseases on the island. Lazear became one of its four members -- the only one with experience in mosquito research. He began growing mosquito larvae from the laboratory of Dr. Carlos Finlay, who had long argued that mosquitoes transmitted yellow fever. In Lazear's breakthrough discovery, mosquitoes that had fed on an active case of yellow fever 12 days before did indeed transmit the disease to two volunteers during experiments in late August. "I rather think I am on the track of the real germ," Lazear wrote on September 8, 1900.

Final Sacrifice
About a week later, Lazear fell ill. He had not told his colleagues that he experimented on himself but notes he took at the time gave evidence that he did. Lazear died of yellow fever on September 25, 1900, at age 34. "He was a splendid, brave fellow," wrote Walter Reed, the head of the Yellow Fever Board, "and I lament his loss more than words can tell; but his death was not in vain. His name will live in the history of those who have benefited humanity." In tribute to their fallen comrade, members of the Yellow Fever Board in November opened "Camp Lazear," where follow-up experiments cemented the link between mosquitoes and yellow fever.

Camp Lazear | HSL University of Virginia

Today Lazear is remembered in the place he began his career, with a brass plaque at Johns Hopkins Hospital commemorating his sacrifice: "With more than the courage and devotion of the soldier, he risked and lost his life to show how a fearful pestilence is communicated and how its ravages may be prevented."

Support Provided by: Learn More