Yellow fever cycle, both in Africa and South America, a sylvatic cycle (forest or jungle cycle) is present, where "Aedes africanus" (in Africa) or mosquitoes of the genus "Haemagogus" and "Sabethes" (in South America) serve as vectors. In the jungle, the mosquitoes infect mainly nonhuman primates; the disease is mostly asymptomatic in African primates. In South America, the sylvatic cycle is currently the only way humans can become infected, which explains the low incidence of yellow fever cases on the continent. People who become infected in the jungle can carry the virus to urban areas, where "A. aegypti" acts as a vector.
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