Tiki Tam Tam
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The question of exactly where the transfer took place, and where the 'epidemic' officially first developed has always been controversial. Some have suggested that it is dangerous to even try to find out, as AIDS has frequently been blamed on an innocent person or group of individuals in the past. However, scientists remain keen to find the true origin of HIV, as most agree it is important to understand the virus and its epidemiology in order to fight it.
So did it definitely come from Africa?
Given the evidence we have already looked at, it seems highly likely that Africa was indeed the continent where the transfer of HIV to humans first occurred (monkeys from Asia and South America have never been found to have SIVs that could cause HIV in humans). In May 2006, the same group of researchers who first identified the Pan troglodytes troglodytes strain of SIVcpz, announced that they had narrowed down the location of this particular strain to wild chimpanzees found in the forests of Southern Cameroon. By analysing 599 samples of chimp droppings (P. T. troglodytes are a highly endangered and thus protected species that cannot be killed or captured for testing), the researchers were able to obtain 34 specimens that reacted to a standard HIV DNA test, 12 of which gave results that were virtually indistinguishable from the reactions created by human HIV. The researchers therefore concluded that the chimpanzees found in this area were highly likely the origin of both the pandemic Group M of HIV-1 and of the far rarer Group N. The exact origins of Group O however remain unknown.
HIV Group N principally affects people living in South-central Cameroon, so it is not difficult to see how this outbreak started. Group M, the group that has caused the worldwide pandemic, was however first identified in Kinshasa, in the Democratic Republic of Congo. It is not entirely clear how it transferred from Cameroon to Kinshasa, but the most likely explanation is that an infected individual travelled south down the Sangha river that runs through Southern Cameroon to the River Congo and then on to Kinshasa, where the Group M epidemic probably began.
Just as we do not know exactly who spread the virus from Cameroon to Kinshasa, how the virus spread from Africa to America and beyond also remains a mystery. It is quite possible that separate 'pockets' of the virus could have been developing in a number of different countries years before the first cases were ever officially identified, making it virtually impossible to trace one single source.
What caused the epidemic to spread so suddenly?
There are a number of factors that may have contributed to the sudden spread of HIV, most of which occurred in the latter half of the twentieth century.
Travel
Both national and international travel undoubtedly had a major role in the initial spread of HIV. In the US, international travel by young men making the most of the gay sexual revolution of the late 70s and early 80s would certainly have played a large part in taking the virus worldwide. In Africa, the virus would probably have been spread along truck routes and between towns and cities within the continent itself. However, it is quite conceivable that some of the early outbreaks in African nations were not started by Africans infected with the 'original' virus at all, but by people visiting from overseas where the epidemic had been growing too. The process of transmission in a global pandemic is simply too complex to blame on any one group or individual.
Much was made in the early years of the epidemic of a so-called 'Patient Zero' who was the basis of a complex "transmission scenario" compiled by Dr. William Darrow and colleagues at the Centre for Disease Control in the US. This epidemiological study showed how 'Patient O' (mistakenly identified in the press as 'Patient Zero') had given HIV to multiple partners, who then in turn transmitted it to others and rapidly spread the virus to locations all over the world. A journalist, Randy Shilts, subsequently wrote an article based on Darrow's findings, which named Patient Zero as a gay Canadian flight attendant called Gaetan Dugas. For several years, Dugas was vilified as a 'mass spreader' of HIV and the original source of the HIV epidemic among gay men. However, four years after the publication of Shilts' article, Dr. Darrow repudiated his study, admitting its methods were flawed and that Shilts' had misrepresented its conclusions.
While Gaetan Dugas was a real person who did eventually die of AIDS, the Patient Zero story was not much more than myth and scaremongering. HIV in the US was to a large degree initially spread by gay men, but this occurred on a huge scale over many years, probably a long time before Dugas even began to travel.
The Blood Industry
As blood transfusions became a routine part of medical practice, an industry to meet this increased demand for blood began to develop rapidly. In some countries such as the USA , donors were paid to give blood, a policy that often attracted those most desperate for cash; among them intravenous drug users. In the early stages of the epidemic, doctors were unaware of how easily HIV could be spread and blood donations remained unscreened. This blood was then sent worldwide, and unfortunately most people who received infected donations went on to become HIV positive themselves.
In the late 1960's haemophiliacs also began to benefit from the blood clotting properties of a product called Factor VIII. However, to produce this coagulant, blood from hundreds of individual donors had to be pooled. This meant that a single donation of HIV+ blood could contaminate a huge batch of Factor VIII. This put thousands of haemophiliacs all over the world at risk of HIV, and many subsequently contracted the virus.
Drug Use
The 1970s saw an increase in the availability of heroin following the Vietnam War and other conflicts in the Middle East , which helped stimulate a growth in intravenous drug use. This increased availability and together with the development of disposable plastic syringes and the establishment of 'shooting galleries' where people could buy drugs and rent equipment, provided another route through which the virus could be passed on.
It is likely that we will never know exactly how or when the AIDS actually originated. Scientists investigating the possibilities often become very attached to their individual 'pet' theories and insist that theirs is the only true answer, but the spread of AIDS could quite conceivably have been induced by a combination of many different events. Whether through injections, travel, wars, colonial practices or genetic engineering, the realities of the 20th Century have undoubtedly had a major role to play. So perhaps what we should be focussing on now is not how the AIDS epidemic originated, but how we can treat those affected by it, continue to prevent the spread of HIV and change our world to ensure a similar pandemic is never allowed to occur again.
Hope that helps to know about AIDS.
So did it definitely come from Africa?
Given the evidence we have already looked at, it seems highly likely that Africa was indeed the continent where the transfer of HIV to humans first occurred (monkeys from Asia and South America have never been found to have SIVs that could cause HIV in humans). In May 2006, the same group of researchers who first identified the Pan troglodytes troglodytes strain of SIVcpz, announced that they had narrowed down the location of this particular strain to wild chimpanzees found in the forests of Southern Cameroon. By analysing 599 samples of chimp droppings (P. T. troglodytes are a highly endangered and thus protected species that cannot be killed or captured for testing), the researchers were able to obtain 34 specimens that reacted to a standard HIV DNA test, 12 of which gave results that were virtually indistinguishable from the reactions created by human HIV. The researchers therefore concluded that the chimpanzees found in this area were highly likely the origin of both the pandemic Group M of HIV-1 and of the far rarer Group N. The exact origins of Group O however remain unknown.
HIV Group N principally affects people living in South-central Cameroon, so it is not difficult to see how this outbreak started. Group M, the group that has caused the worldwide pandemic, was however first identified in Kinshasa, in the Democratic Republic of Congo. It is not entirely clear how it transferred from Cameroon to Kinshasa, but the most likely explanation is that an infected individual travelled south down the Sangha river that runs through Southern Cameroon to the River Congo and then on to Kinshasa, where the Group M epidemic probably began.
Just as we do not know exactly who spread the virus from Cameroon to Kinshasa, how the virus spread from Africa to America and beyond also remains a mystery. It is quite possible that separate 'pockets' of the virus could have been developing in a number of different countries years before the first cases were ever officially identified, making it virtually impossible to trace one single source.
What caused the epidemic to spread so suddenly?
There are a number of factors that may have contributed to the sudden spread of HIV, most of which occurred in the latter half of the twentieth century.
Travel
Both national and international travel undoubtedly had a major role in the initial spread of HIV. In the US, international travel by young men making the most of the gay sexual revolution of the late 70s and early 80s would certainly have played a large part in taking the virus worldwide. In Africa, the virus would probably have been spread along truck routes and between towns and cities within the continent itself. However, it is quite conceivable that some of the early outbreaks in African nations were not started by Africans infected with the 'original' virus at all, but by people visiting from overseas where the epidemic had been growing too. The process of transmission in a global pandemic is simply too complex to blame on any one group or individual.
Much was made in the early years of the epidemic of a so-called 'Patient Zero' who was the basis of a complex "transmission scenario" compiled by Dr. William Darrow and colleagues at the Centre for Disease Control in the US. This epidemiological study showed how 'Patient O' (mistakenly identified in the press as 'Patient Zero') had given HIV to multiple partners, who then in turn transmitted it to others and rapidly spread the virus to locations all over the world. A journalist, Randy Shilts, subsequently wrote an article based on Darrow's findings, which named Patient Zero as a gay Canadian flight attendant called Gaetan Dugas. For several years, Dugas was vilified as a 'mass spreader' of HIV and the original source of the HIV epidemic among gay men. However, four years after the publication of Shilts' article, Dr. Darrow repudiated his study, admitting its methods were flawed and that Shilts' had misrepresented its conclusions.
While Gaetan Dugas was a real person who did eventually die of AIDS, the Patient Zero story was not much more than myth and scaremongering. HIV in the US was to a large degree initially spread by gay men, but this occurred on a huge scale over many years, probably a long time before Dugas even began to travel.
The Blood Industry
As blood transfusions became a routine part of medical practice, an industry to meet this increased demand for blood began to develop rapidly. In some countries such as the USA , donors were paid to give blood, a policy that often attracted those most desperate for cash; among them intravenous drug users. In the early stages of the epidemic, doctors were unaware of how easily HIV could be spread and blood donations remained unscreened. This blood was then sent worldwide, and unfortunately most people who received infected donations went on to become HIV positive themselves.
In the late 1960's haemophiliacs also began to benefit from the blood clotting properties of a product called Factor VIII. However, to produce this coagulant, blood from hundreds of individual donors had to be pooled. This meant that a single donation of HIV+ blood could contaminate a huge batch of Factor VIII. This put thousands of haemophiliacs all over the world at risk of HIV, and many subsequently contracted the virus.
Drug Use
The 1970s saw an increase in the availability of heroin following the Vietnam War and other conflicts in the Middle East , which helped stimulate a growth in intravenous drug use. This increased availability and together with the development of disposable plastic syringes and the establishment of 'shooting galleries' where people could buy drugs and rent equipment, provided another route through which the virus could be passed on.
It is likely that we will never know exactly how or when the AIDS actually originated. Scientists investigating the possibilities often become very attached to their individual 'pet' theories and insist that theirs is the only true answer, but the spread of AIDS could quite conceivably have been induced by a combination of many different events. Whether through injections, travel, wars, colonial practices or genetic engineering, the realities of the 20th Century have undoubtedly had a major role to play. So perhaps what we should be focussing on now is not how the AIDS epidemic originated, but how we can treat those affected by it, continue to prevent the spread of HIV and change our world to ensure a similar pandemic is never allowed to occur again.
Hope that helps to know about AIDS.
