Naked Science Forum
Life Sciences => Cells, Microbes & Viruses => Topic started by: fuxxor on 01/06/2004 17:20:54
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I'm sorry if somebody already covered this question, but I am receiving countless questions as to the origin of AIDS and some of them are extremely absurd! Perhaps the most ridiculous one would be...
Aids came from a dude who had sex with a monkey.
I don't really know where it came from, but I would like to know the EXACT truth. I also heard that AIDS and HIV originated from the homosexual community of America, particularly the men. Since the only form of sexual pleasure a homosexual can enjoy with another homosexual is sodomy or oral sex, then it is safe to assume that AIDS comes from the former. Since there are blood vessels closer to the rectal area it is easier to spread infection, disease, and all sorts of good stuff.
Anyways, where didAIDS come from???
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Concerning the monkeys.... Theoreticaly, it could be. But, it is much more possible that there were people who were eating row monkey meat...
There are also theories that HIV came from laboratory, and that it is artificialy created, but it`s more like a subject for the X-files than for serious disscusion. Or, if you like conspiration theory ...[:)]
Concerning homosexual, they have greater probability to injure during sex, due to the unnatural features of it.
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Aids was originaly a disease in African monkeys which were used to make vaccinations for people in Africa. However there was cross species contamination. The monkeys used, the vaccinations and the area of Aids origin coincides.
Titanscape
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This is why they won't risk a pig organ to human transplant. Also viruses are exchanged thru body fluids. It is disgusting. Semen and those easily broken blood vessels in bowels. Vaginas are stronger. Oral sex with a condom is safest, however it is foul eh? Shared needles are dangerous. Saliva apparently is not.
You might like to check my thread on "Amoebas and white blood cells spot the difference".
Titanscape
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hmmm... so basically, the origin of aids hasn't been determined, but it is identified as a monkey disease.
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The popularly accepted theory is that it originally developed in monkeys but that may or may not be true. Simian IV could have evolved in parallel with HIV or even cross-contaminated the OTHER way. We didn't discover monkey IV until after HIV, so we don't know for sure. It's all speculation at this point.
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They later discovered that the monkees there had a virus surely similar to HIV. A documentary I saw detailed how it came thru a medicine made from ground... animal organs. A prize winning Dr who developoed the medicine then lost his good name.
Titanscape
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I went to an interesting lecture once about this subject (although was a few years back now). They were looking at the genetic material in different HIV strains to try and trace its ancestry.
I can't remember the details, but I remember being utterly convinced that the "was because monkeys used to make vaccine" conspiracy therory was way off course (I think due to the species of monkey..?)
The most likely cause (not sure if still considered thus) came across as being simply that it was from people eating diseased monkeys (like BSE from Scrapie, zoonosis, innit).
The idea of it arising spontaneously in the homosexual population is simply a reflection of the depressing homophobia still rampant in society. Whenever did a disease spontaneously arise?! It was simply spread more readily among a population which is more likely to engage in anal sex (more bodily fluid mixing than vaginal sex) and, in sections of that community, more likely to live a promiscuous lifestyle. I recently read some history of how HIV/AIDS was handled by the world media and it really is disgusting - even respectable media repeating the ridiculous idea that it was some sort of punishment from God. It's amazing how many people had to die before it was even mentioned by the mainstream media, and then only because people started realising that you could get it if you were straight.
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What did the aussie say when asked what anal sex is like?
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"Buggered if I know?"
Titanscape
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I don't have anything original to add, but have heard the monkey source as well. It has been speculated it was from killing and eating monkeys, and that the first victim was bitten by an injured, and bloody monkey. Plausible, but if so, then monkeys should have human IV, no? Simian IV is distinct, so where did simian IV become human IV?
The only speculation for that, is that the simean IV was transmitted, and subsequently mutated into its human, virulent form. If so, then there should also be non-virlulent forms of HIV in the human population.
The transmission of HIV has been blamed on many things, but it is a sexually transmitted disease, so that is how it was spread. In Africa, it was spread by both homo and heterosexual contact. In America, primarily homosexual. Heteros are less promiscuous than homosexuals, and HIV is a disease spread by promiscuity. Do not assume I am damning promiscuity here. I'm glad there was no HIV in my college days!
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I'll do this in 2 parts. For today here is a bit of biology about HIV :
HIV stands for Human Immunodeficiency Virus. Long term chronic infection with this agent, at least in most people, leads to eventually immunocompromise and a syndrome of opportunistic infection referred to as AIDS.
HIV is a retrovirus and belongs to a class of viruses termed 'lentiviruses' or 'slow' viruses because (compared with smallpox, or the flu for instance) they progress at an indolent pace.
The HIV genome is encoded in a short piece of RNA about 10 kilobases (kb) in length which, upon infecting a cell, is converted into a piece of DNA using an enzyme carried by the virus called reverse transcriptase. This piece of DNA is subsequently integrated into the host cell's genomic DNA (producing a so-called pro-virus) and is used as a template for synthesising the RNA for new viral particles.
The viral RNA is packaged inside a particle measuring about 100nm across (about 1/10,000th of a millimetre). The particle consists of an outer envelope studded with mushroom-like proteins called gp120 and gp41 which act like molecular grappling hooks and help the virus to lock on to its target cells. Beneath the outer envelope is another protein layer, called the matrix, which encloses the viral core, or capsid, where the RNA sits, together with 3 enzymes, p51 (the reverse transcriptase), p11 (a protease) and p32 (the integrase that inserts the DNA copy of the viral genome into the host cell DNA).
The gp120/41 surface proteins carried by HIV allow it to lock onto and enter cells of the immune system including lymphocytes and cells of the monocyte/macrophage lineage. The virus gains entry by binding to a receptor called CD4, together with a class of chemokine co-receptor called CXCR4 and CCR5.
Infection begins within any CD4 positive cells at the site of inoculation. Initial replication at the point of first contact amplifies the infecting dose and the virus buds off from the infected cell to track down other susceptible cells. In particular, viral particles are carried to local lymph nodes where they infect follicular dendritic cells and T lymphocytes (the primary viral target).
This initial burst of viral replication, and associated viraemia (virus detectable in the bloodstream), lasts for about 3 months. During this time the infected individual often experiences acute flu-like symptoms, known as a sero-conversion illness, which can include temperatures, sweats, diarrhoea, weight loss, swollen glands (lymphadenopathy) and weakness. Whilst this is going on the virus can reach high levels in the blood stream and the numbers of CD4 T lymphocytes detectable in the blood can fall by up to 40%.
After about 3 months most patients will have produced antibodies to HIV, the levels of CD4 cells rebound to almost normal, the level of virus in the bloodstream becomes very low and the patient usually feels completely well again.
They remain this way for many years (8 to 10 on average, without treatment), despite a low-grade smouldering HIV infection which slowly and inexorably dismantles the immune system until the patient becomes immunocompromised and succumbs to an opportunistic AIDS-defining illness. These include unusual forms of tuberculosis (TB), thrush, problems related to CMV (cytomegalovirus), toxoplasmosis, HSV (herpes simplex), cryptococcus and PCP (pneumocystis carinii pneumonia). AIDS-defining illnesses usually kick-in when the CD4 count falls below 200 (i.e. about a fifth of normal).
At this point, if these diseases are not controlled, they can prove fatal. Indeed, HIV doesn't kill people - it's the opportunistic infections that do. Fortunately there are several lines of attack including drugs to control the opportunists, and drugs to control HIV.
In my next post I'll discuss the treatments for HIV (past, present and future), and where HIV came from in the first place.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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quote:
Originally posted by Titanscape
Aids was originaly a disease in African monkeys which were used to make vaccinations for people in Africa. However there was cross species contamination. The monkeys used, the vaccinations and the area of Aids origin coincides.
This was for a short time speculated upon, but we now believe that HIV was in the human population long before the polio vaccine was being developed in monkeys.
http://library.thinkquest.org/03oct/01335/en/txt/history.html
quote:
Although the new epidemic that would eventually be named Acquired Immune Deficiency Syndrome (AIDS) was first recognized as a disease in 1981, we now know that human immuno-deficiency virus (HIV) probably jumped from chimpanzees to humans during the late 1600s. The first actually confirmed death from HIV was in 1959, when a man died in the Congo in Africa. This was confirmed by analyzing samples of his blood in a recent test. To look at HIV's history in more detail, click on the links above.
http://evolve.zoo.ox.ac.uk/papers/Rambaut%20et%20al%20(2004)%20Nature%20Reviews%20Genetics.pdf
quote:
The timescale of evolution inferred from viral
MOLECULAR CLOCKS also seems incompatible with longterm
co-divergence. If co-divergence were true, then
the divergence times of SIVs should broadly match
those of their hosts, going back millions of years.
However, all molecular clock estimates of primate
lentivirus evolution are orders of magnitude more
recent than this14, and the rates of mutation and replication
are similar among these viruses15,16. Therefore, if
molecular clocks are accurate, then the evolutionary
timescale for each epidemic of HIV-1 and HIV-2 is
measured only in decades. Several methods are available
to measure substitution rates, and therefore
divergence times, in RNA viruses, although the most
reliable estimates come from analysing the temporal
distribution of nodes on trees (BOX 2). Application of
these (and similar) methods have led to suggestions
that the M group of HIV-1 originated in the 1930s,
with a range of ~10 years on either side17–19 (but see
BOX 2). A broadly similar evolutionary timescale has
been proposed for HIV-2 (REF. 20).
Although most estimates for the time of origin of
HIV-1 are consistent, all can be subject to the same systematic
bias. Once again, recombination might contribute
to this error.Recombination has complex effects
on the estimation of divergence times, by increasing
apparent variation in rates among nucleotide sites and
reducing genetic distances between sequences21,22. In
these circumstances, perhaps the only reliable indicators
of the timescale of HIV evolution are archival viral samples.
The earliest HIV-1 M group sequence that is available
was sampled in the Democratic Republic of Congo
in 1959 (REF. 23). That this sequence falls some distance
from the root of the M group tree is strong evidence
that the diversification of these viruses occurred before
this time (BOX 2).Accurately dating HIV evolution will
require the analysis of more such ‘fossil’ viruses.
As you can see, there is quite a bit of disagreement about exactly when HIV jumped from simian to human, but it is generally recognised to have been too early for it to gave originated from the polio vaccine.
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Okay, I must venture opinions on this thread.
First, the HIV organism did probably penetrate humans around that 1950s time in my view. How? No need to stipulate anal sex with monkeys, that is just silly. The facts are that monkess and Chimpanzees are hunted for food extensively (many species now face extinction due to this) in Africa, and in one or much such episode, it is likely that a bite or a cut allowed the infected blood to pass between the two species. Not very different from the Chicken farmers in Thailand and Turkey who recently died from coming into contact with the H5N1 flu from their chickens. The human hunter then was able to pass it on through sexual contacts (it is also silly to call HIV a homosexual disease at this point, after many millions of Africans have died from getting it heterosexually). A disease like HIV can be invisible in a place like Africa for a long time, because in Africa there are many obscure slow acting diseases. So we became conscious of it in the 1980s when thousands of Americans were becoming ill- and when French researchers finally were able to identify the virus.
Conspiracy theories are not necesary to explain the awesome destructive power of HIV. Such theories only serve to make us falsely feel safer or provide somebody to "blame" for the existence of a microbe. It just happened, get over it. The real question now is how to change our behaviors so that we can keep prevent another 40 million people from contracting it.
chris wiegard
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quote:
Originally posted by VAlibrarian
Okay, I must venture opinions on this thread.
First, the HIV organism did probably penetrate humans around that 1950s time in my view. How? No need to stipulate anal sex with monkeys, that is just silly. The facts are that monkess and Chimpanzees are hunted for food extensively (many species now face extinction due to this) in Africa, and in one or much such episode, it is likely that a bite or a cut allowed the infected blood to pass between the two species. Not very different from the Chicken farmers in Thailand and Turkey who recently died from coming into contact with the H5N1 flu from their chickens. The human hunter then was able to pass it on through sexual contacts (it is also silly to call HIV a homosexual disease at this point, after many millions of Africans have died from getting it heterosexually). A disease like HIV can be invisible in a place like Africa for a long time, because in Africa there are many obscure slow acting diseases. So we became conscious of it in the 1980s when thousands of Americans were becoming ill- and when French researchers finally were able to identify the virus.
Conspiracy theories are not necesary to explain the awesome destructive power of HIV. Such theories only serve to make us falsely feel safer or provide somebody to "blame" for the existence of a microbe. It just happened, get over it. The real question now is how to change our behaviors so that we can keep prevent another 40 million people from contracting it.
chris wiegard
I think the evidence is that the transfer from Chimpanzee to Human was probably a little before the 1950's, but otherwise I would substantially agree with you.
The first recorded death from AIDS was in 1959. Since the incubation period is upwards of 8 years, that would imply infection prior to 1951 (albeit, it may be argued that immediately after the species jump, there may have been a much shorter incubation period). But, this was the first recorded case, and one can suspect that there must have been a good number of unrecorded cases prior to that in fact, one would expect that most bush meat would be consumed by relatively isolated communities who would not register on most epidemiological data bases, and by the time the disease would have been spotted by someone presenting themselves to a hospital, I could imagine a fair few people in isolated villages would have died in total anonymity.
It is also very highly probable that there would have been several independent points at which the disease would have transferred to humans, in many cases simply dying out without ever creating an epidemic, it only becoming an epidemic when it started reaching large urban conurbations.
George