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
1793 Philadelphia yellow fever epidemic was also advocated by Dr. Edward Stevens, who in mid-September claimed it had cured Alexander Hamilton, Secretary of the Treasury, of the fever. Rush searched the medical literature for other approaches. Benjamin Franklin had given him letters sent by Dr. John Mitchell, related to treating patients during a 1741 yellow fever outbreak in Virginia. (Franklin never published the letters.) Mitchell noted that the stomach and intestines filled with blood and that these organs had to be emptied at all costs. "On this account," Mitchell argued, "an ill-timed scrupulousness about the weakness of the body is of bad consequences in these