CAN MOSQUITOES TRANSMIT DISEASES LIKE AIDS? Mosquitoes suck whole blood together with all its contained viruses, bacteria and other pathogens, including HIV. Luckily for humans, the HIV virus cannot be spread by mosquitoes . This is because of several reasons accounting for the inability of mosquitoes to transmit HIV. First of all, the feeding mechanism of mosquitoes does not promote transmission, it is not like a hypodermic needle injecting blood . The sucking "snout" of a mosquito is has six mouthparts. Four of these are used for piercing the skin that the mosquito is biting. The other two mouth parts consist of two tubes. One tube sends saliva into the host and the other sends blood up into the mosquito. This two tube system does not allow for mixing. It is one major reason why mosquitoes are unable to transmit HIV. Only saliva is injected into humans when a mosquito bites and thus HIV positive blood that a mosquito may have previously ingested is never tr