There is now a wealth of evidence on how, when and where HIV first began to cause illness in humans. You can find out more about the origins and history of HIV through our interactive timelinewhere you can read, watch, listen and explore key events from the history of the epidemic. 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. They discovered that the chimps had hunted and eaten two smaller species of monkeys red-capped mangabeys and greater spot-nosed monkeys.
HIV-1 from chimpanzees and gorillas to humans[ edit ] Scientists generally accept that the known strains or groups of HIV-1 are most closely related to the simian immunodeficiency viruses SIVs endemic in wild ape populations of West Central African forests.
Exactly when the zoonosis occurred is not known. Some molecular dating studies suggest that HIV-1 group M had its most recent common ancestor MRCA that is, started to spread in the human population in the early 20th century, probably between and Sample analyses resulted in little data due to the rarity of experimental material.
The researchers, however, were able to hypothesize a phylogeny from the gathered data. They were also able to use the molecular clock of a specific strain of HIV to determine the initial date of transmission, which is estimated to be around They all seem to derive from independent transmissions from sooty mangabeys to humans.
Groups C and D have been found in two people from Liberiagroups E and F have been discovered in two people from Sierra Leoneand groups G and H have been detected in two people from the Ivory Coast.
These HIV-2 strains are probably dead-end infectionsand each of them is most closely related to SIVsmm strains from sooty mangabeys living in the same country where the human infection was found. The resulting exposure to blood or other bodily fluids of the animal can result in SIV infection.
Since rural Africans were not keen to pursue agricultural practices in the jungle, they turned to non-domesticated meat as their primary source of protein. This over-exposure to bushmeat and malpractice of butchery increased blood-to-blood contact, which then increased the probability of transmission.
A study published in also discussed that bushmeat in other parts of the world, such as Argentina, may be a possible location for where the disease originated. The primary point of entry, according to researchers, is somewhere in the jungles of Argentina or Brazil. This suggests that the zoonotic transmission of the virus may have happened in this area.
However these relationships do not explain more detailed patterns of biogeography, such as why epidemic HIV-2 groups A and B only evolved in the Ivory Coastwhich is one of only six countries harboring the sooty mangabey. All of them propose that the simultaneous epidemic emergences of four HIV groups in the late 19th-early 20th century, and the lack of previous known emergences, are explained by new factor s that appeared in the relevant African regions in that timeframe.
These new factor s would have acted either to increase human exposures to SIV, to help it to adapt to the human organism by mutation thus enhancing its between-humans transmissibilityor to cause an initial burst of transmissions crossing an epidemiological threshold, and therefore increasing the probability of continued spread.
Sharpand their colleagues proposed that "[the epidemic emergence of HIV] most likely reflects changes in population structure and behaviour in Africa during the 20th century and perhaps medical interventions that provided the opportunity for rapid human-to-human spread of the virus".
A largely masculine labor force was hastily recruited to work in fluvial and sea ports, railways, other infrastructures, and in plantations.
This disrupted traditional tribal values and favored casual sexual activity with an increased number of partners. In the nascent cities women felt relatively liberated from rural tribal rules  and many remained unmarried or divorced during long periods,   this being rare in African traditional societies.
Michael Worobey and colleagues observed that the growth of cities probably played a role in the epidemic emergence of HIV, since the phylogenetic dating of the two older strains of HIV-1 groups M and Osuggest that these viruses started to spread soon after the main Central African colonial cities were founded.
Several historical sources support the view that bushmeat hunting indeed increased, both because of the necessity to supply workers and because firearms became more widely available.Then in , an international team of researchers reported that they had discovered the origins of HIV-1, the predominant strain of HIV in the developed world.
A subspecies of chimpanzees native to west equatorial Africa had been identified as the original source of the virus. The common narrative holds that the spread of HIV and AIDS among humans can be traced back to one flight attendant in the s.
But while that individual certainly did spread the virus, he was. Genetic studies of the virus suggested in that the most recent common ancestor of the HIV-1 M group dates back to the Belgian Congo city of Léopoldville The Origins of AIDS, the virus can be traced to a central African bush hunter in , with colonial medical campaigns using improperly sterilized syringe and needles playing a key.
The origins and evolution of HIV Version Anne Fischer Formerly of the Max Planck Since , when it first began to spread widely, HIV has caused the deaths of 25 million people worldwide.
HIV, the virus that causes AIDS, can be transmitted through: • unprotected sex (in semen or vaginal fluid);. The Origin of the AIDS Virus. Rick Sowadsky From Rick AIDS was identified as a new disease in Human immunodeficiency virus (HIV) was co-discovered several years later by Luc Montagnier.
According to Pépin's book, The Origins of AIDS, the virus can be traced to a central African bush hunter in , with colonial medical campaigns using improperly sterilized syringe and needles playing a key role in enabling a future epidemic. Pépin concludes that AIDS spread silently in Africa for decades, fueled by urbanization and prostitution since the initial cross-species infection.