Yellow Fever

Abstract

Other than smallpox, perhaps no disease has influenced major events shaping the development of North and Central America than yellow fever. This fatal disease—with 50 % mortality—destroyed the economies of many Southern American cities. Yellow fever inhibited the attempts of the French to establish an empire in the Western Hemisphere, using Haiti as a base. This resulted in the sale of the Louisiana Territories to the U.S., resulting in doubling the size of the country. Attempts to build a canal across the Isthmus of Panama failed because of disease, and yellow fever killed more troops in Cuba than were casualties of hostilities in the Spanish–American War. These events led to the formation of a U.S. commission, headed by Walter Reed, to investigate the causes of yellow fever. Carlos Finlay, a Cuban scientist, had suggested some 20 years before the establishment of the commission, that mosquitoes transmitted yellow fever. This was tragically confirmed when two members of the commission allowed themselves to be bitten by yellow fever-loaded mosquitoes. One died and the other suffered chronic illness. Reed established a camp with volunteers to test the hypothesis and proved without a doubt that the insects spread the disease. Later commissions confirmed these results and a virus was eventually isolated, although not without other casualties among the researchers. Max Theiler, at the Rockefeller Institute, developed a vaccine which is used to this day. Outbreaks of yellow fever still occur in Africa and areas of South America.