4. Human Interaction with Vectors

A diagram explaining the transfer of vectors through mosquitos

In all cases of the spread of diseases, the bite is the essential part of transmission of a vector from a host to carrier, and from a carrier to host. If neither the carrier or host are infected, the disease is not transmitted in any way, and only blood and saliva are exchanged. This is a completely different story when the human is infected- then the pathogen can be transferred to the carrier, and, in a few days, the infectious mosquito can transfer the vector by biting another person through its saliva.