It is believed that the HIV

It is believed that the HIV virus inherits its properties from a virus SIV (Simian Immunodeficiency Virus), which is found in monkeys. The AIDS virus also has developed its own characteristics along with those which it inherits from SIV. The SIV virus has exactly same genetic structure as that of HIV and both the viruses are transmitted same way from one host to another. The SIV virus causes AIDS in monkeys and has exactly same effects on them but it does not show any such effect on humans, whereas HIV causes AIDS in humans but not in monkeys. There are again many interesting stories/guesses/hypothesis as how the HIV virus born from the SIV virus? And how SIV virus got mixed in the human blood?

The AIDS virus was first discovered around year 1980 in the United States. A group of young gay men and also some drug users; were getting ill often, and there was no trace of the disease that they were suffering from. Most of the diseases they were falling prey of were related to the immune system. As it was not known that how much time the disease takes to surface? And how the disease spreads? The virus of AIDS found new home for itself from one man to another in the same group and also those who came in sexual contact or used the same syringe which was used by infected person. After some months, people from the group began to die, the diseases which killed all those people, were some of the common diseases which affects human at much extent if they have a damaged immune system. The T cells, also known as CD4 cells which help human body in fighting with the diseases were found damaged and there level was lowered in the patients suffering from the mysterious disease. It was outbreak of the new disease and it was identified and named AIDS (Acquired Immune Deficiency Syndrome) in 1981. Doctors started research in order to find out the possible causes of the disease. First, it was not known whether AIDS was caused by viral infection or something else until two doctors Luc Montagnier and Robert Gallo found the virus causing AIDS. The virus was named Human Immunodeficiency Virus (HIV).