There’s an idea that because HIV is fragile and can’t tolerate exposure to oxygen, that means the instant blood leaves the body it’s totally safe.
Some HIV conspiracy nutters even think this is “proof” that HIV could not have come from people slaughtering monkeys for meat, because if you’re butchering an infected animal, its blood touches the air, and then if you cut yourself and you are exposed to the animal’s blood, well, the blood touched air so it can’t infect you.
So let’s think about this.
The virus has a fragile capsid—the outer shell—that’s destroyed on contact with air. A naked virus on its own that is exposed to air is inactivated.
Ah, but blood is a liquid.
A naked virus inside a drop of liquid is not exposed to air until the liquid evaporates!
And are viruses usually naked?
Viruses are tiny strands of RNA or DNA wrapped in a case made of protein molecules. They reproduce by entering a cell and taking over the cell, hijacking it to manufacture more viruses.
A virus inside a cell is not exposed to air until the cell dries out and ruptures.
A virus inside a cell inside a drop of liquid is pretty well protected from air.
Now, once the liquid dries out, the cell shrivels and then ruptures and it’s adios, muchachos. But as long as the blood is still wet, it’s potentially infectious.
A needle that has been on the ground for hours has dried out. Whatever blood was on or in it, it’s long past the point of being infectious. To my knowledge, there has never once been a case of HIV infection from a dirty needle sitting out for hours.
However, if the blood is still wet? Yes, it can still infect you. Air is not Magic HIV Death Cooties. The umpire doesn’t call “safe!” the instant blood leaves the body, direct fluid contact with wet, HIV-positive blood can infect you.
