In the late 19th century, the crucial question with regard to yellow fever was, "How is the disease spread?" Observations from the numerous outbreaks in American and Cuba supported the idea that unsanitary conditions fostered the disease. Many believed that direct contact with an infected person, as well as contact with any infected clothing or bedding, could result in infection.
Carlos Finlay , a Cuban doctor and researcher, theorized that mosquitoes were responsible for transmitting the disease by biting an infected person and carrying the disease to an uninfected person. But he was unable to prove this theory with scientific certainty.
Walter Reed's team tested Finlay's theory in the summer of 1900 and uncovered a critical detail: test subjects who contracted yellow fever were bitten by mosquitoes that had been infected at least 12 days earlier. Reed surmised that the virus incubated within the mosquitoes before it became an infectious agent. Reed devised the Camp Lazear experiment to account for an incubation period.
Exclusive Corporate Funding is provided by: