Virology<unk>  virus <unk> V), is a member of the genus Alphavirus, and family Togaviridae. It was first isolated in 1953 in Tanzania and is an RNA virus with a positive-sense single-stranded genome of about 11.6kb. It is a member of the Semliki Forest virus complex and is closely related to Ross River virus, O'nyong'nyong virus, and Semliki Forest virus. Because it is transmitted by arthropods, namely mosquitoes, it can also be referred to as an arbovirus (arthropod-borne virus). In the United States, it is classified as a category B priority pathogen, and work requires biosafety level III precautions. Transmission<unk>  is generally transmitted from mosquitoes to humans. Less common modes of transmission include vertical transmission, which is transmission from mother to child during pregnancy or at birth. Transmission via infected blood products and through organ donation is also theoretically possible during times of outbreak, though no cases have yet been documented. The incubation period ranges from one to twelve days, and is most typically three to seven.<unk>  is related to mosquitoes, their environments, and human behavior. The adaptation of mosquitoes to the changing climate of North Africa around 5,000 years ago made them seek out environments where humans stored water. Human habitation and the mosquitoes' environments were then very closely connected. During periods of epidemics humans are the reservoir of the virus. Because high amounts of virus are present in the blood in the beginning of acute infection, the virus can be spread from a viremic human to a mosquito, and back to a human. During other times, monkeys, birds and other vertebrates have served as reservoirs. Three genotypes of this virus have been described, each with a distinct genotype and antigenic character: West African, East/Central/South African, and Asian genotypes. The Asian lineage originated in 1952 and has subsequently split into two lineages – India (Indian Ocean Lineage) and South East Asian clades. This virus was first reported in the Americas in 2014. Phylogenetic investigations have shown that there are two strains in Brazil – the Asian and East/Central/South African types – and that the Asian strain arrived in the Caribbean (most likely from Oceania) in about March 2013. The rate of molecular evolution was estimated to have a mean rate of 5 × 10−4 substitutions per site per year (95% higher probability density 2.9–7.9 × 10−4).<unk>  is spread through bites from Aedes mosquitoes, and the species A. aegypti was identified as the most common vector, though the virus has recently been associated with many other species, including A. albopictus. Research by the Pasteur Institute in Paris has suggested<unk>  virus strains in the 2005-2006 Reunion Island outbreak incurred a mutation that facilitated transmission by the Asian tiger mosquito (A. albopictus). Other species potentially able to transmit<unk>  virus include Ae. furcifer-taylori, Ae. africanus, and Ae. luteocephalus.
Chikungunya
Zika fever
Yellow fever
Dengue fever
Trench fever
Rocky Mountain spotted fever
Cuban fever
Blackwater fever