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
2016 Angola and DR Congo yellow fever outbreak mission to Angola was its first deployment. The team included "emergency medical teams, public health and medical coordination experts, mobile biosafety laboratories, medical evacuation planes and logistical support teams". Efforts to prevent international spread are confounded by the practice of selling falsified yellow fever vaccination certificates. The fake cards are sold to people who are required to have proof of vaccination after travel to areas where yellow fever is endemic. On 11 February 2016, the Pasteur Institute (WHO) in Senegal warned of fake yellow fever vaccine on the international market. With help from the World Health Organization (WHO), the Angolan