Yellow fever by their newly discovered canals, which were perhaps made to absorb carbon and prevent the disease. 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
Yellow fever on the African continent. In 2008, the largest number of recorded cases was in Togo. In 2016, a large outbreak originated in Angola and spread to neighboring countries before being contained by a massive vaccination campaign. In March and April, 11 cases were reported in China, the first appearance of the disease in Asia in recorded history. Phylogenetic analysis has identified seven genotypes of yellow fever viruses, and they are assumed to be differently adapted to humans and to the vector "A. aegypti". Five genotypes (Angola, Central/East Africa, East Africa, West Africa I, and West Africa II) occur only in