Probably HIV started as a virus in monkey or apes that mutated enough to be transmitted to humans. Many animals have immunodeficiency viruses. There's a feline "AIDS" in cats and the SIV virus in monkeys. That's "simian immunodeficiency virus."
One suspect is the African Green Monkey, an animal that is both social and aggressive and comes into villages and bites people. If that SIV had mutated enough to become the human type (HIV), once spread to humans it would be spread by human to himan contact. It only takes one infected human having sex with another to start the process.
There is evidence that the virus has been around much longer than we thought. We became aware of it in the 1980's but they have recovered what seems to be the virus in specimens from the 1950's.
2006-07-09 21:00:28
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answer #1
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answered by Anonymous
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From infected monkeys in Africa, that bit a human or humans. An Aids version viruses is carried in monkeys, but monkeys dont get sick from it because they have had it for a long time, and their imune system has learned to adapt to it.
2006-07-10 03:53:51
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answer #2
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answered by Anonymous
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The AIDS epidemic was discovered June 5, 1981, when the U.S. Centers for Disease Control and Prevention reported a cluster of Pneumocystis carinii pneumonia (now classified as Pneumocystis jiroveci pneumonia) in five homosexual men in Los Angeles.[96] Originally dubbed GRID, or Gay-Related Immune Deficiency, health authorities soon realized that nearly half of the people identified with the syndrome were not homosexual men. In 1982, the CDC introduced the term AIDS to describe the newly recognized syndrome.
Three of the earliest known instances of HIV infection are as follows:
A plasma sample taken in 1959 from an adult male living in what is now the Democratic Republic of Congo.[97]
HIV found in tissue samples from a 15 year old African-American teenager who died in St. Louis in 1969.[98]
HIV found in tissue samples from a Norwegian sailor who died around 1976.[99]
Two species of HIV infect humans: HIV-1 and HIV-2. HIV-1 is more virulent and more easily transmitted. HIV-1 is the source of the majority of HIV infections throughout the world, while HIV-2 is not as easily transmitted and is largely confined to West Africa.[100] Both HIV-1 and HIV-2 are of primate origin. The origin of HIV-1 is the Central Common Chimpanzee (Pan troglodytes troglodytes) found in southern Cameroon.[101] It is established that HIV-2 originated from the Sooty Mangabey (Cercocebus atys), an Old World monkey of Guinea Bissau, Gabon, and Cameroon.
Although a variety of theories exist explaining the transfer of HIV to humans, there is no widely accepted scientific consensus of any single hypothesis and the topic remains controversial. Freelance journalist Tom Curtis discussed one currently controversial possibility for the origin of HIV/AIDS in a 1992 Rolling Stone magazine article. He put forward what is now known as the OPV AIDS hypothesis, which suggests that AIDS was inadvertently caused in the late 1950s in the Belgian Congo by Hilary Koprowski's research into a polio vaccine.[102] Although subsequently retracted due to libel issues surrounding its claims, the Rolling Stone article motivated another freelance journalist, Edward Hooper, to probe more deeply into this subject. Hooper's research resulted in his publishing a 1999 book, The River, in which he alleged that an experimental oral polio vaccine prepared using chimpanzee kidney tissue was the route through which simian immunodeficiency virus (SIV) crossed into humans to become HIV, thus starting the human AIDS pandemic.[103] Subsequently, this hypothesis has been refuted by examination of these original polio vaccine stocks and establishing that they do not contain material of chimpanzee origin.[104]
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Alternative theories
Main article: AIDS reappraisal
A minority of scientists and activists question the connection between HIV and AIDS,[105] or the existence of HIV,[106] or the validity of current testing methods. These claims are met with resistance by, and often evoke frustration and hostility from most of the scientific community, who accuse the dissenters of ignoring evidence in favor of HIV's role in AIDS, and irresponsibly posing a dangerous threat to public health by their continued activities.[107]
Some assert that the current mainstream approach to AIDS, based on HIV causation, has resulted in inaccurate diagnoses, psychological terror, toxic treatments, and a squandering of public funds.[108] The debate and controversy regarding this issue from the early 1980s to the present has provoked heated emotions and passions from both sides.
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Common misconceptions
Main article: Common misconceptions about HIV and AIDS
A number of misconceptions have arisen surrounding HIV/AIDS. Three of the most common are that AIDS can spread through casual contact, that sexual intercourse with a virgin will cure AIDS, and that HIV can infect only homosexual men and drug users.
One possibility for the misconception that AIDS infects only homosexual men is that AIDS was termed Gay Related Immune Deficiency Syndrome when it was first recognized in 1981 (it was subsequently renamed after it was recognised that there were methods of transmission other than male-male intercourse). HIV appears to have entered the United States around the late 1960s and seems to have then been unknowingly spread by homosexuals throughout the U.S. and Europe. In a survey on AIDS conducted in 1983 in Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Norway, Sweden, Switzerland, and the United Kingdom a slight majority of those infected with HIV were male homosexuals (58% of all cases).[109]
2006-07-10 08:34:10
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answer #3
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answered by Linda 7
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