HOW DID HIV COME INTO EXISTENCE?
The origin of HIV/AIDS is mystery for the scientists. The disease is a kind of puzzle. The first case of HIV/AIDS was discovered in USA in early 1980s. One of the interesting questions about HIV/AIDS is that how did it came into existence?? It is believed that it originated in Africa. But how?

It is believed that HIV is a descendent of SIV (simian immunodeficiency virus) which is found in chimpanzees. However, the virus has some significant difference from the HIV.

Certain viruses can be transferred from one species to another. And this kind of viral transfer between animal and human is called zoonosis. It is strongly believed that by zoonosis only HIV came into existence.