This document discusses flaviviruses, which are enveloped, single-stranded RNA viruses that are icosahedral in shape and include dengue virus and yellow fever virus. These viruses are transmitted by mosquitoes and have pigs, bats, horses and humans as hosts. Control and prevention methods include eliminating mosquito breeding areas, controlling adult and larvae populations, avoiding prime mosquito hours, and using repellents. For human infections, there is no specific treatment and the disease is typically self-limiting. Some flaviviruses can infect equine and swine.