Yellow fever is caused by yellow fever virus, an enveloped RNA virus 40–50 nm in width, the type species and namesake of the family Flaviviridae. It was the first illness shown to be transmissible by filtered human serum and transmitted by mosquitoes, by Walter Reed around 1900. 
The evolutionary origins of yellow fever most likely lie in Africa. The virus as well as the vector Aedes aegypti, a mosquito species, were probably brought to the western hemisphere and the Americas by slave trade ships from Africa after the first European exploration in 1492.
This reaction, known as yellow fever vaccine-associated acute viscerotropic disease (YEL-AVD), causes a fairly severe disease closely resembling yellow fever caused by virulent strains of the virus. The risk factors for YEL-AVD are not known, although it has been suggested that it may be genetic.
Yellow fever peaked in 1842, killing hundreds of people. There was an outbreak in Philadelphia in 1793. Yellow fever is spread through the bite of an infected mosquito. The name of the mosquito which commonly carries the virus is Aedes Aegypti. The female carries the disease. The yellow fever originated in Central Africa.
Yellow Fever is the sixth album by the American blues rock band Hot Tuna, recorded and released in 1975 as Grunt BFL1-1238. The album was also released in Quadraphonic as Grunt BFD1-1238. The album rose to #97 on the Billboard charts. 1 Track listing
Yellow Fever is a play by R. A. Shiomi which takes place on Powell Street in Japantown, Vancouver, a gathering place for the local Japanese-Canadian culture. Set in the 1970s, the Sam Spade -like main character, Sam Shikaze, must work to unravel the mysteries that surround him.
Rockefeller Yellow Fever Commission researchers first isolate the causative agent of yellow fever disease, the yellow fever virus, from a Ghanaian patient named Asibi. The Asibi yellow fever virus strain is still widely used by scientists today.
Yellow fever epidemics became seen as a national crisis. When in 1855 a French doctor published an 813-page history of yellow fever in Philadelphia, covering outbreaks from 1699 to 1854, he devoted only a few pages to the 1793 epidemic.
Yellow fever has been a source of several devastating epidemics. Cities as far north as New York, Philadelphia, and Boston were hit with epidemics. In 1793, one of the largest yellow fever epidemics in U.S. history killed as many as 5,000 people in Philadelphia—roughly 10% of the population.