ABSTRACT
In 1900 there was an epidemic of yellow fever among the US troops stationed in Havana after the Spanish–American war. Fifteen years earlier it had been suggested by Charles Finlay 1 that mosquitoes carried the disease from man to man, but this had been largely ignored and the US Secretary of War appointed a four-man medical board of Walter Reed and three assistants, Carroll, Agramonte and Lazear, ‘to pursue scientific investigations with reference to the infectious disease prevalent on the island of Cuba. 2 Following the theory of Finlay, they hatched mosquitoes from eggs, induced the insects to bite patients with known yellow fever and then maintained colonies of presumably infected mosquitoes for experiments. Some of these bit Carroll, Lazear and a volunteer from the US Army, Private Dean, and all contracted yellow fever. Carroll and Dean recovered but unfortunately Lazear died. However, it had been shown that mosquitoes carried the disease from man to man.
