Scientists discovered viruses that were sexually transmitted between chimpanzees. One of these was able to be spread to humans. Scientists believe that this virus was HIV, and that humans got HIV from chimpanzees. Scientists also learned that HIV causes AIDS. There are many theories for how HIV and AIDS spread between humans. One theory says in the 1950's, syringes cost a lot of money, and colors didn't want to buy a lot f them. So, some doctors would use the same syringe on multiple patients, without sterilizing them in between. This would allow virus to easily be transmitted between people. Another theory says that hunters would get HIV from eating chimps they killed, or from the blood of the chimps going into a cut on a hunters body.
Aids has infected 70 million people, and over the next decade, will infect 40 million more.
As of right now, there is not a cure for AIDS. However, many organizations are giving money to scientists to help them find a cure for it. One of these organizations, PEPFAR, was created by George W Bush. Scientists have learned that antiretroviral therapy makes AIDS less deadly. It is being used to help keep people alive. Also, medical services are becoming more available, which allows more people to be treated. Many years ago, these medical services weren't as wide spread as they are now.