The sample was retrospectively analysed and HIV detected. The first verified case of HIV is from a blood sample taken in 1959 from a man living in what is now Kinshasa in the Democratic Republic of Congo. Studies of some of the earliest known samples of HIV provide clues about when it first appeared in humans and how it evolved. 8 When and where did HIV start in humans? As a result, it infects far fewer people, and is mainly found in a few countries in West Africa like Mali, Mauritania, Nigeria and Sierra Leone. It is far rarer, and less infectious than HIV-1. 7 The crossover to humans is believed to have happened in a similar way (through the butchering and consumption of monkey meat). HIV-2 comes from SIVsmm in sooty mangabey monkeys rather than chimpanzees. The most studied strain of HIV is HIV-1 Group M, which is the strain that has spread throughout the world and is responsible for the vast majority of HIV infections today. This explains why there is more than one strain of HIV-1. This supports the hunter theory because every time SIV passed from a chimpanzee to a human, it would have developed in a slightly different way within the human body, and produced a slightly different strain. There are four main groups of HIV strains (M, N, O and P), each with a slightly different genetic make-up. 5 Normally, the hunter's body would have fought off SIV, but on a few occasions the virus adapted itself within its new human host and became HIV-1. In this scenario, SIVcpz was transferred to humans as a result of chimps being killed and eaten, or their blood getting into cuts or wounds on people in the course of hunting.
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The most commonly accepted theory is that of the 'hunter'. 4 How did HIV cross from chimps to humans? This is the strain that can also infect humans. The two different SIV strains then joined together to form a third virus (SIVcpz) that could be passed on to other chimps. These smaller monkeys infected the chimps with two different strains of SIV. They discovered that the chimps had hunted and eaten two smaller species of monkeys (red-capped mangabeys and greater spot-nosed monkeys). The same scientists then conducted more research into how SIV could have developed in the chimps. The researchers who discovered this connection concluded that it proved chimpanzees were the source of HIV-1, and that the virus had at some point crossed species from chimps to humans.
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In 1999, researchers found a strain of SIV (called SIVcpz) in a chimpanzee that was almost identical to HIV in humans. HIV-1 is closely related to a strain of SIV found in chimpanzees, and HIV-2 is closely related to a strain of SIV found in sooty mangabeys. Research found that HIV is related to SIV and there are many similarities between the two viruses. In a similar way, the Simian Immunodeficiency Virus (SIV) attacks the immune systems of monkeys and apes. HIV is a type of lentivirus, which means it attacks the immune system. You can find out more about the origins and history of HIV through our interactive timeline, where you can read, watch, listen and explore key events from the history of the epidemic. There is now a wealth of evidence on how, when and where HIV first began to cause illness in humans. The origin of the Human Immunodeficiency Virus (HIV) has been a subject of scientific research and debate since the virus was identified in the 1980s.
![the story of the human body reddit the story of the human body reddit](https://img3.grunge.com/img/gallery/the-mystery-of-spontaneous-human-combustion/rise-to-flame-1500581127.jpg)
This was probably as a result of chimps carrying the Simian Immunodeficiency Virus (SIV), a virus closely related to HIV, being hunted and eaten by people living in the area. HIV crossed from chimps to humans in the 1920s in what is now the Democratic Republic of Congo.