Yellow fever was the first illness shown to be transmissible by filtered human serum and transmitted by mosquitoes, by Walter Reed around 1900. The positive-sense, single-stranded RNA is around 11,000 nucleotides long and has a single open reading frame encoding a polyprotein. Host proteases cut this polyprotein into three structural (C, prM, E) and seven nonstructural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5); the enumeration corresponds to the arrangement of the protein coding genes in the genome. Minimal yellow fever virus (YFV) 3'UTR region is required for stalling of the host 5'-3' exonuclease XRN1. The UTR contains PKS3 pseudoknot structure which
Yellow fever the Louisiana Purchase to the US in 1803. In 1804, Haiti proclaimed its independence as the second republic in the Western Hemisphere. The yellow fever epidemic of 1793 in Philadelphia, which was then the capital of the United States, resulted in the deaths of several thousand people, more than 9% of the population. The national government fled the city, including President George Washington. Additional yellow fever epidemics struck Philadelphia, Baltimore, and New York City in the 18th and 19th centuries, and traveled along steamboat routes from New Orleans. They caused some 100,000–150,000 deaths in total. In 1853, Cloutierville, Louisiana, had