<P> The planets were in the same line as the sun and earth and this produced, besides Cyclones, Earthquakes, etc., a denser atmosphere holding more carbon and creating microbes . Mars had an uncommonly dense atmosphere, but its inhabitants were probably protected from the fever by their newly discovered canals, which were perhaps made to absorb carbon and prevent the disease . </P> <P> In 1848, Josiah C. Nott suggested that yellow fever was spread by insects such as moths or mosquitoes, basing his ideas on the pattern of transmission of the disease . Carlos Finlay, a Cuban doctor and scientist, proposed in 1881 that yellow fever might be transmitted by mosquitoes rather than direct human contact . Since the losses from yellow fever in the Spanish--American War in the 1890s were extremely high, Army doctors began research experiments with a team led by Walter Reed, and composed of doctors James Carroll, Aristides Agramonte, and Jesse William Lazear . They successfully proved Finlay's" mosquito hypothesis". Yellow fever was the first virus shown to be transmitted by mosquitoes . The physician William Gorgas applied these insights and eradicated yellow fever from Havana . He also campaigned against yellow fever during the construction of the Panama Canal . A previous effort of canal building by the French had failed (in part due to mortality from the high incidence of yellow fever and malaria, which killed many workers). </P> <P> Although Dr. Walter Reed has received much of the credit in United States history books for "beating" yellow fever, he had fully credited Dr. Finlay with the discovery of the yellow fever vector, and how it might be controlled . Reed often cited Finlay's papers in his own articles, and also credited him for the discovery in his personal correspondence . The acceptance of Finlay's work was one of the most important and far - reaching effects of the Walter Reed Commission of 1900 . Applying methods first suggested by Finlay, the United States government and Army eradicated yellow fever in Cuba and later in Panama, allowing completion of the Panama Canal . While Reed built on the research of Finlay, historian François Delaporte notes that yellow fever research was a contentious issue . Scientists, including Finlay and Reed, became successful by building on the work of less prominent scientists, without always giving them the credit they were due . Reed's research was essential in the fight against yellow fever . He is also credited for using the first type of medical consent form during his experiments in Cuba, an attempt to ensure that participants knew they were taking a risk by being part of testing . </P> <P> Like Cuba and Panama, Brazil also led a highly successful sanitation campaign against mosquitoes and yellow fever . Beginning in 1903, the campaign led by Oswaldo Cruz, then director general of public health, not only resulted in eradicating the disease, but also reshaped the physical landscape of Brazilian cities, such as Rio de Janeiro, as well . During rainy seasons, Rio de Janeiro had regularly suffered floods, as water from the bay surrounding the city overflowed into Rio's narrow streets . Coupled with the poor drainage systems found throughout Rio, this created swampy conditions in the city's neighborhoods . Pools of stagnant water stood year long in city streets and proved to be a fertile ground for disease - carrying mosquitoes . Thus, under Cruz's direction, public health units known as "mosquito inspectors" fiercely worked to combat yellow fever throughout Rio by spraying, exterminating rats, improving drainage, and destroying unsanitary housing . Ultimately, the city's sanitation and renovation campaigns reshaped Rio de Janeiro's neighborhoods . Its poor residents were pushed from city centers to Rio's suburbs, or to towns found in the outskirts of the city . In later years, Rio's most impoverished inhabitants would come to reside in favelas . </P>

Who is credited with the discovery of the cause of yellow fever
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