Hands up those who know what the biggest killer in the world is?
No, not drugs, not bullets. No, not even the United States.
Actually the correct answer is Malaria, that rather nasty disease spread by mosquito bites. It kills more people than heroin, AIDS and Uncle Sam combined. Why is this?
Yes it's the mosquito doing it, being able to spread Malaria anywhere a mosquito can live, mostly in hot climates.
Now consider AIDS, a really rubbish disease that not only can't live outside a host for more than 10 seconds, but then doesn't kill you. It instead destroys your immune system and lets something else come along to give you an early appointment with the Grim Reaper.
However, it is still one of the most contagious diseases around without a cure, but thankfully isn't transferred by mosquitos, because the mosquito's gut destroys it.
Unfortunatly, viruses are brilliant are building resistances to practically anything that stops them.
When the day comes that AIDS finds a way to survive living in a mosquito, we may be in real trouble.