AIDS is caused by the Human Immunodeficiency Virus (HIV) which basically pisses off your T cells so much that they run out and when another infection occurs you have no T cells to fight it off.
HIV does cause AIDS. It's (unfortunately) been proven by Koch's postulates when there was an accident in a research lab and some researchers infected themselves with pure HIV and subsequently got AIDS.
HIV is transmitted by sexual contact (a**l, vaginal, or oral), from mother to child through pregnancy or through birthing or through breast feeding, or by contaminated needles. You can only get HIV by swapping bodily fluids with a person who's infected. Will you get it by standing next to someone or through normal skin to skin contact? No. Will you get it by rubbing your open wound on their open wound? Probably. Also that's gross.
In 2009 according to the WHO, there were 33.3 million people living with AIDS, 2.6 million people acquired AIDS, and 1.8 million people died from AIDS.
This epidemic is the worst in Sub-Saharan Africa. Only about 10% of the world's population lives in Sub-Saharan Africa; however, that 10% contains about 70% of all people infected with HIV.
So, what can you do to help? Well, we love languages, right? So we're the perfect people to TELL OTHER PEOPLE ABOUT IT! Increasing education about how HIV is spread and about safe sex is one of the best ways to prevent AIDS.

Thank you for reading to my rant, and I do hope you help spread awareness.
If you'd like more information you can go to this CDC run website.
(All of my information comes from my professors or from the WHO website on HIV/AIDS).
