Dengue fever the same genus include yellow fever virus, West Nile virus, Zika virus, St. Louis encephalitis virus, Japanese encephalitis virus, tick-borne encephalitis virus, Kyasanur forest disease virus, and Omsk hemorrhagic fever virus. Most are transmitted by arthropods (mosquitoes or ticks), and are therefore also referred to as arboviruses ("ar"thropod-"bo"rne viruses). The dengue virus genome (genetic material) contains about 11,000 nucleotide bases, which code for the three different types of protein molecules (C, prM and E) that form the virus particle and seven other non-structural protein molecules (NS1, NS2a, NS2b, NS3, NS4a, NS4b, NS5) that are found in infected host cells only
Yellow fever probably transferred to North and South America with the importation of slaves from Africa, part of the Columbian Exchange following European exploration and colonization. The first definitive outbreak of yellow fever in the New World was in 1647 on the island of Barbados. An outbreak was recorded by Spanish colonists in 1648 in the Yucatán Peninsula, where the indigenous Mayan people called the illness "xekik" ("blood vomit"). In 1685, Brazil suffered its first epidemic, in Recife. The first mention of the disease by the name "yellow fever" occurred in 1744. McNeill argues that the environmental and ecological disruption caused by