Yellow fever reach the stomach of the mosquito, and if the virus concentration is high enough, the virions can infect epithelial cells and replicate there. From there, they reach the haemocoel (the blood system of mosquitoes) and from there the salivary glands. When the mosquito next sucks blood, it injects its saliva into the wound, and the virus reaches the bloodstream of the bitten person. Transovarial and transstadial transmission of the yellow fever virus within "A. aegypti", that is, the transmission from a female mosquito to her eggs and then larvae, are indicated. This infection of vectors without a previous blood meal
Yellow fever many to outbreaks in 1804, 1814, and 1828. Barcelona suffered the loss of several thousand citizens during an outbreak in 1821. Urban epidemics continued in the United States until 1905, with the last outbreak affecting New Orleans. In Colonial times and during the Napoleonic Wars, the West Indies were known as a particularly dangerous posting for soldiers due to yellow fever being endemic in the area. The mortality rate in British garrisons in Jamaica was seven times that of garrisons in Canada, mostly because of yellow fever and other tropical diseases such as malaria. Both English and French forces posted