Sequencing of Yellow Fever Virus.

The yellow fever virus (YFV) is a single-stranded positive-sense RNA virus with a genome of approximately 11 kb. Currently, seven strains have been described: five in Africa (West Africa I and II, East Africa, East/Central Africa, and Angola) and two in the Americas (South America I and II). Phylogenetic studies have provided evidence that the YFV circulating in the Americas is derived from an ancestor of the West African lineage that emerged in Africa and was imported into the American East Coast of West Africa during the slave trade.