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
1793 Philadelphia yellow fever epidemic atmosphere that might last 50 years and make deadly epidemics almost certain. 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. General 20th-century US histories, such as the 10-volume "Great Epochs in American History," published in 1912, used short excerpts from Carey's account. The first history of the epidemic to draw on more primary sources was J. H. Powell's "Bring Out Your Dead" (1949), but he did not use