system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why hasn't AIDS spread through the country, through mosquito bites?

I would assume they are basically needles, and they spread other blood based diseases. Why not the HIV virus?
gpt
That is actually a really good question. When a mosquito bites someone, it does not inject its own blood or the blood of an animal or person it has bitten into the next person it bites. The mosquito does inject saliva, which acts as a lubricant so that it can feed more effectively. Yellow fever and malaria can be transmitted through the saliva, but HIV does not reproduce in insects, so the virus doesn't survive in the mosquito long enough to be transmitted in the saliva.