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
1793 Philadelphia yellow fever epidemic vector of the 1793 plague in Philadelphia (and other Atlantic ports) was the British merchant ship "Hankey", which had fled the West African colony of Bolama (an island off West Africa, present day Guinea-Bissau) the previous November, trailing yellow fever at every port of call in the Caribbean and eastern Atlantic seaboard. See: "The Ship of Death: The Voyage That Changed the Atlantic World". After two weeks and an increasing number of fever cases, Dr. Benjamin Rush, a doctor's apprentice during the city's 1762 yellow fever epidemic, saw the pattern; he recognized that yellow fever had returned. Rush alerted his