When a mosquito bites a person infected with HIV and later a healthy person, the infection doesn't spread why?
HIV does not survive long outside the human body (such as on surfaces), and it cannot reproduce outside a human host. It is not transmitted

* By mosquitoes, ticks, or other insects.
* Through saliva, tears, or sweat.
* By hugging, shaking hands, sharing toilets, sharing dishes, or closed-mouth or “social” kissing with someone who has HIV.
* Through other sexual activities that don’t involve the exchange of body fluids (for example, touching).
* Through the air. [1]
Mosquitoes can't transmit HIV to humans because the proboscis tube in their mouth that they use to bite humans injects saliva into the bite, but not blood [1]. HIV can't be transmitted through saliva, so it can't be transmitted through a mosquito bite [1, 2]. Even if some HIV were still in a mosquito's body when it bit you, there wouldn't be enough of it to transmit to you [2]. Mosquitoes lack the receptor HIV uses to recognize immune cells, so they can't get an HIV infection [3]. Instead, the virus just gets broken down and digested in the mosquito's stomach [3]. Thus, mosquitoes can't transmit HIV to humans [3].