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
History of yellow fever word of an epidemic would cause a quarantine to be placed on the city, and their trade would suffer. In such epidemics, steamboats frequently carried passengers and the disease upriver from New Orleans to other cities along the Mississippi River. The epidemic was dramatized and featured in the plot of the 1938 film "Jezebel", starring Bette Davis. Yellow fever was a threat in New Orleans and south Louisiana virtually every year, during the warmest months. Among the more prominent victims were: Spanish colonial Governor Manuel Gayoso de Lemos (1799); the first and second wives (d. 1804, 1809) of territorial Governor