Yellow fever and several species of mosquitoes. In cities, it is spread primarily by "Aedes aegypti", a type of mosquito found throughout the tropics and subtropics. The virus is an RNA virus of the genus "Flavivirus". The disease may be difficult to tell apart from other illnesses, especially in the early stages. To confirm a suspected case, blood sample testing with polymerase chain reaction is required. A safe and effective vaccine against yellow fever exists, and some countries require vaccinations for travelers. Other efforts to prevent infection include reducing the population of the transmitting mosquito. In areas where yellow fever is common
Yellow fever vaccine fever certificate of vaccination for travelers. Increases in cases of yellow fever in endemic areas of Africa and South America in the 1980s were addressed by the WHO Yellow Fever Initiative launched in the mid-2000s. The initiative was supported by the Gavi Alliance, a collaboration of the WHO, UNICEF, vaccine manufacturers, and private philanthropists such as the Bill & Melinda Gates Foundation. Gavi-supported vaccination campaigns since 2011 have covered 88 million people in 14 countries considered at "high-risk" of a yellow fever outbreak (Angola was considered "medium risk"). Activities of the Yellow Fever Initiative are managed through an international coordinating