Can you get yellow fever from someone who has it?

Answer 1

No the virus lives in the gut of mosquitos. but if a mosqito bites the other person and then sucks your blood some time later there might be enough virus to infect you... The yellow fever virus is mainly transmitted through the bite of the yellow fever mosquito Aedes aegypti, but other mosquitos can also serve as a vector for the virus. Like other Arboviruses which are transmitted via mosquitos, the yellow fever virus is taken up by a female mosquito which sucks the blood of an infected person. Viruses thus 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 mosquitos) and from there the salivary glands. When the mosquito sucks blood the next time, it injects its saliva into the wound, and thus the virus reaches the blood of the bitten person. There are also indications for a vertical infection of the yellow fever virus with A. aegypti, i.e. the transmission from a female mosquito to her clutch and thus the larva. This infection of vectors without a previous blood meal seems to play a role in single, sudden breakouts of the disease.