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 authorized. After an extensive debate in the newspapers, the State Assembly denied the petition. The recurrences of yellow fever kept discussions about causes, treatment and prevention going until the end of decade. Other major ports also had epidemics, beginning with Baltimore in 1794, New York in 1795 and 1798, and Wilmington in 1798, making yellow fever a national crisis. New York doctors finally admitted that they had had an outbreak of yellow fever in 1791 that killed more than 100 people. All the cities that suffered epidemics continued to grow rapidly. The widespread recognition that the epidemics were based along