Walter Reed and the Yellow Fever Experiments

Major Walter Reed constructed two huts (arrows) - one contaminated with fomites, the other clean but filled with mosquitoes - to determine how yellow fever was transmitted.Credit: National Library of Medicine

The loss of many lives to yellow fever during the 1898 Spanish American War prompted an investigation into how people caught the disease. Major Walter Reed is credited with proving, through a series of experiments with volunteers, that mosquitoes, not contaminated objects, are to blame.