Why isn’t HIV airborne like other diseases ? or at least transmit it through saliva ?

Question

Aren’t organisms trying to find the most hosts so it can have more chances to survive ? sure it would kill all its hosts in short time but organisms don’t rationalize like we do, so why won’t it seek to become way more transmissible ?

In: 7

Answer 1

Saying organisms like viruses are “trying to” or “seek to” do certain things is not accurate. As far as current scientific understanding goes, they do not have any kind of thoughts or planning that would allow them to “try” or “seek.” They have a single purpose in their existence, to spread and multiply, and they go through random mutations that cause them to change over time. The changes that lead to higher rates of spreading and multiplying will be more likely to stick around and continue to spread and multiply. This does not mean they will always move toward maximum infectiousness or maximum reproduction rate, only that they will naturally tend to move in these directions if there are no other things to consider (like being able to avoid or disable an infected host’s defenses).

HIV happens to have evolved in such a way that it can’t survive in the air or in saliva for very long, so it just can’t transmit well by those methods. It does however to a VERY effective job of reproducing and evading the defenses of our immune systems, which is why very few people have ever been fully cured of HIV. When it does infect someone, it sticks around for ages and can spread through sexual contact indefinitely, whereas other viruses like the flu eventually get beaten by the immune system and a person does not stay infected forever.

It’s all a matter of randomness and mutations. HIV is an effective virus (by which I mean it’s successful at spreading and multiplying) despite not being easily spread through air and saliva. There’s a possibility that some strain of HIV could become airborne, but that’s also just a matter of randomness and chance and probably taking a long long long time for many mutations to pile up that make it able to survive in those conditions long enough to infect people.