How a Sick Chimp Led to a Global Pandemic: The Rise of HIV

Here at SciShow, we talk a lot about the fascinating,
complicated, and often very weird stories of discovery and collaboration that led to
the science we know today. But one of the strangest is something we haven’t
covered in much detail before, and it’s a biggie: the decades it took to figure out
exactly what HIV and AIDS were, and how to prevent and treat them. Since the start of the AIDS crisis, some 70
million people have been infected with HIV, and 35 million of those people have died. Both those numbers are staggering in their
own way, and together, they tell the story of a disease that has led to an incredible
amount of loss, but also one that — if you’re lucky enough to have access to the right medicines
— is no longer a death sentence. So, in honor of World AIDS Day on December
1, we want to tell you that story. There’s a lot to cover, so we’ll do it
in two parts. This episode, we’ll go over how we figured
out what HIV is, when the infection morphs into AIDS, and where we think the virus came
from. Next time, we’ll look back to the earliest
treatments, the arrival of antiretroviral drugs, which were complete game-changers,
and go over the creative ways scientists are now thinking about prevention and possibly
even a cure. But first, the basics. HIV, or human immunodeficiency virus, is a
retrovirus that infects immune cells, most notably what are known as CD4 T cells. The “retrovirus” part just means that
the virus uses RNA — DNA’s more wily, less stable cousin — as its genetic material,
and that once HIV infects a cell, it makes a DNA version of its genome with a special
enzyme, then inserts that DNA into the host genome. If that sounds sneaky — well, it is. And it’s part of why HIV has been so difficult
to treat, which we’ll talk about more next time. Now, those CD4 T cells that HIV infects and
ultimately kills are a kind of white blood cell known as ‘helper’ T cells. When they recognize a threat, they pump out
proteins that help coordinate a bunch of different immune responses. You definitely want them around. HIV is spread by bodily fluids, including
blood, semen, vaginal fluid, and breast milk. That’s why HIV can be transmitted through
sex, dirty needles, breastfeeding, and any other swapping of fluids you might do — with
a major exception: saliva isn’t one of those fluids. Saliva is full of other stuff that prevents
HIV from being infectious, like antibodies and a bunch of antimicrobial proteins. So unless there’s a lot of blood in your
saliva for some reason, it can’t transmit HIV. When someone is first infected, they might
feel like they have a bout of the flu, with a fever, headache, rash, sore throat, and
muscle and joint pain. That’s because the virus is infecting lots
of cells and the immune system is trying to fight it off. But within a few weeks those symptoms pass
because by then the person has specific antibodies that can keep the virus from running totally
rampant. After that, they usually feel fine for a long
time — in many cases, a really long time, like several decades. Until, one day, they don’t, because the
virus has finally killed off too many T cells, leaving the body unable to properly defend
itself against pathogens — anything that might be dangerous or infectious. That’s when someone is said to have AIDS,
or acquired immune deficiency syndrome. Usually AIDS is diagnosed once the person’s
T cell count falls below 200 cells per microliter of blood, which is well below the normal 500-1500,
or if they develop what’s called an opportunistic infection. These are infections that anyone with a reasonably
strong immune system would be able to fight off, easy-peasy. But because HIV has obliterated most of their
T cells, AIDS patients get sick. And, they can die. Most of the time it’s an opportunistic infection
that killed them. So, some of that was probably familiar to
you, but pretend for a moment that you’ve never heard of HIV or anything else I just
mentioned. Because back in the ‘80s, we didn’t know
these basic facts. All doctors knew was that suddenly, healthy
young gay men were developing extremely rare infections and cancers — and, it was killing
them. One of the first people to notice the pattern
was an immunologist at UCLA. Between the fall of 1980 and the following
spring, he saw a string of five patients, all gay men in their 20s or 30s, with an unusual
kind of pneumonia. There was a fungus growing inside their lungs. Normally, the fungus was totally harmless
and would never infect the lungs, but in these men it had, and it was making it hard for
them to breathe. The patients also had oral thrush — basically
yeast infections in their mouths — and few CD4 T cells. By June, when the immunologist wrote up the
results for the CDC’s weekly Mortality and Morbidity report, two patients had died. A month later, a dermatologist in New York
chimed in with a similarly disturbing report, this time with Kaposi’s sarcoma, a rare
cancer where patients develop blotchy purple lesions on their skin. In two and a half years, 26 young gay men
in New York and LA had been diagnosed with Kaposi’s. Some also had the weird fungal pneumonia,
and 8 had died. It’s hard to imagine now, but at this point,
scientists had no idea what was making people sick. They didn’t know if it was some sort of
toxin or a pathogen. And if it was an infection of some kind, they
didn’t know how it was spreading. That meant they couldn’t warn people about
how to protect themselves. The association with gay men, though, was
certainly striking, and early on, many called the mystery disease GRID, for gay-related
immune deficiency. Lots of people would talk about it as the
“gay cancer” or “gay plague.” But the disease wasn’t limited to gay men. It was turning up in hemophiliacs — people
whose blood doesn’t clot properly and are treated with clotting factors taken from other
people’s blood. Doctors were also seeing cases in IV drug
users, women, infants, and heterosexual men. In particular, 20 recent immigrants from Haiti
had gotten sick, and none said they were gay. Those clues were important, because they told
scientists the disease — which had finally been given the name AIDS — was probably
infectious, and probably transmitted by blood. There were other diseases that spread in similar
ways, like hepatitis B. So in March of 1983, the CDC issued a warning
that doctors needed to be careful about blood transfusions, and that the disease seemed
to spread through both gay and straight sex. Debates about the specifics, including whether
it could spread through saliva, would happen later. But what was the infectious agent? The race was on for scientists to figure out
what was causing the disease. French molecular biologist Luc Montagnier
suspected a virus because at the time, the blood products hemophiliacs used were filtered
for things like bacteria and fungi. But viruses were too small to catch. So along with his colleague Françoise Barré-Sinoussi,
he searched cells taken from AIDS patients and found a retrovirus. Around the same time, Robert Gallo at the
NIH in the US also identified a retrovirus in samples from AIDS patients. Both groups published their work in May 1983,
and shortly afterward another team found yet another retrovirus. All the viruses had been given different names,
and at first, it’s wasn’t totally obvious that they were the same thing. But they were, and in 1986, the cause of AIDS
had been given an official name: HIV. So, HIV was the problem, but where had it
come from, and why had the epidemic struck now, in the decade of big hair and Michael
Jackson? While some researchers were scrambling to
identify whatever it was that made AIDS infectious, others noticed that macaque monkeys also seemed
to suffer from an AIDS-like disease. One group decided to take some blood samples
from these sick monkeys, and in 1985 they found a virus that was similar to HIV. It was eventually called SIV, for simian immunodeficiency
virus. Researchers started to think that HIV might
have come from our primate relatives, jumping the species barrier. After a lot of work, they figured out that
the virus behind the epidemic was very similar to the chimpanzee version of SIV, and they
were the ones who had passed it to us. But how exactly? There’s no real way to put this delicately,
but most scientists agree that the reason why SIV made the leap into humans — what’s
called a spillover — is because we had a taste for bushmeat, or wild game. In this case, monkeys and chimps. This is known as the cut-hunter hypothesis. In the course of butchering a chimpanzee,
some SIV-infected chimp blood enters a small cut on the hunter’s hand. Or, a bit of blood splatters in their mouth. The virus is close enough to human biology
to infect the hunter, and over time, if the hunter passes the virus along to enough people,
it evolves into the HIV we know today. Spillovers like these happened many times
— we can tell because the virus mutates quickly, and by looking at genetic differences,
we can identify multiple lineages of the virus, each one corresponding to a spillover. We’ve traced the current epidemic to just
one of these, called ‘M’ for main. By analyzing chimpanzee pee and poop, researchers
think the chimps who passed that version of the virus to us lived in southwestern Cameroon,
in the forests near the Congo. And based on the oldest blood samples we can
find that we now know have HIV in them, which are from 1959 and 1960, scientists estimate
that HIV-1 first infected humans around 1908. If that seems like a long time ago, well,
it takes a while for a virus to take off. By the 1920s, it’s thought that the virus
traveled downriver — in a person, of course — to the burgeoning city of Kinshasa, then
known as the Belgian colonial city of Leopoldville. There weren’t many women around other than
prostitutes, so experts think HIV spread that way, and possibly through injectable drugs
the colonists used to treat some tropical and venereal diseases. This was before disposable syringes, and nurses
were trying to treat lots of people with just a few of them, so the syringes may have only
been rinsed with alcohol before being used on the next patient. So the very methods meant to stop the spread
of disease may have actually been
encouraging it. With time, infected people in Kinshasa left
to go to other places, and they did the unavoidable: they brought the virus with them. Because the virus mutates so quickly, we can
group the viruses into 9 different subtypes and get a sense of how HIV traveled around
the world from Central Africa. Several subtypes spread to other parts of
Africa. Subtype C went south and then landed in India. Subtype B went to Haiti — and then, through
several quirks of history, came to the US. First, in 1960, when the Belgians left the
Congo, French-speaking Haitians started to arrive in the Congo to work as doctors, lawyers,
and other professionals. But with the creation of Zaire in 1965, the
immigrants felt unwelcome, so they went back to Haiti, bringing HIV with them. There, HIV expanded especially quickly, possibly
because of a plasmapheresis center where people could get paid to donate their blood plasma. The center used a machine that mixed the blood
of different donors, allowing viruses to transfer. By 1982, nearly 8 percent of a group of young
mothers in a Port-au-Prince slum were HIV-positive — an astoundingly high number. HIV is thought to have entered the US around
1969, with just one infected person or unit of plasma from Haiti. It took about a decade for anyone to notice,
but by then it was too late. The epidemic had begun, and HIV was not only
in the Americas, but Europe and Asia, too. And now that it was here, we needed to figure
out how to fight it. But we’ll get to that in the next episode
of this mini-series. In the meantime, thanks for watching this
episode of SciShow, and if you want to learn more about HIV and all kinds of other science,
you can go to youtube.com/scishow and subscribe.

Glenn Chapman


  1. This is chimp to human hokum. Heterosexuals', have the same kind of sex, that men to men have. Can you say fake news that keeps repeating itself? Symptoms of all kinds known, and unknown that will occur, when the person does not have, a spine, that has a healthy shape.,{Prevention is paramount. Knowing where to go is important. Upper cervical heath centers. The Spesific. NUCCA, Upcspine. Wai8t 4 – 5 days after an accident, fall, or hit to the head.

  2. Prostitutes in India were found to be immune to hiv. However not other STDs
    Next, there are different mutations
    More studies required
    Anyway I believe hiv goes way back
    We were told first report case of aids death in usa in 1950s
    Or death from pneumonia. Could have been caused by aids

  3. Nobel Prize winning microbiologist Gary Null said that there ISN'T ANY STUDY that proves HIV causes AIDS ( YOUTUBE VIDEO). Nomorefakenews.com is offering a $10,000 reward to anyone who can find a study proving that HIV causes AIDS.

  4. Has anyone ever thought that hiv popped from simian to human via beastiality? Like honestly tho

  5. my great-uncle died in 1977, at age 66, of aids/hiv.arc. the doctors told us his multitude of illnesses were psychosomatic and/or he was faking them. ff a decade and a half: watching a good friend dying and seeing KS up close was like getting hit in the face with an anvil. i will never forget the horror, as an 11 year old child, seeing his back and legs ravaged by the rare skin cancer. and then again as an adult once i put the two together. apologies if my comment is hard to follow as i still find it very difficult putting these two scenarios into words

  6. When he said there was no delicate way to say it, I was sure he was going to say that someone had sex with a monkey

  7. Do you think AIDS is a natural occurrence? Mmm I do not!

    I think, It was a bio weapon that escaped early.

  8. I've always found the simian jump to humans very plausible,but surely people have been eating bushmeat alot Futher back than the 80's

  9. I feel like this is the perfect video to drop this: so, the cure for aids is actually liquidising a large wad of cash, then directly injecting it intk your bloodstream with a needle. It works. It cured little Eric and little Kyle πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚

  10. people talk about HIV was first transmitted thru sex between humans and chimps, mind you a wild chimps. That’s not practical. How? To me, I believe that Chimps are not sexually attracted to other species. They aren’t pets, therefore, they won’t cooperate quickies with humans.

  11. An animal with an unknown deadly disease
    A hazmat suit, gasoline and fire

  12. I was 14 yrs old in 1983, I remember the huge scare that whole decade on the news over AIDS…. it scared me to death, or rather from death…..Thank you Africa, for giving the world AIDS.

  13. πŸ“—πŸ€”How weird, & Evil scientists really operates..πŸ™„πŸ€¨πŸ˜ŒyepπŸ’¬


  14. Genetically engineered virus. This is mans work not a sick chimp. I aint buying it

  15. So everything wrong with the world they blame The Blacks. Why did we not hear of blacks dropping like flies untill ten years after thery dropped like flies first. Because it was tested on their most promiscuous and undesirables in their race first and then launched on the Blacks during the smallpox missionary work… Man made Evil genius…. Just ingeniously evil!!!! Wow Satan is very impressive!!!

  16. This brings me back to the hysteria and panic of when we first leaned about HIV/AIDS but didn't understand it and Reagan joking about it…

  17. How to eradicate the spread of HIV ? HIV tests should be mandatory to everyone once a month. It's already 2019 near 2020. Private hospitals offer the test for only $10 just to assure 100% secrecy of your medical records.

  18. If HIV started from chimpanzee then the cure could come from the chimpanzee aswell. They should have been extinct by now. compare to human population they are smaller. They hunt and eat each other, they breast feed their young and they dont practice safe sex. So why are they still around?

  19. So you can't get HIV from saliva? Great! That means I can still kiss my mom goodnight!

  20. I had a friend that has HIV and he mentioned medicline does that have anything to do with it?

  21. HIV -AIDS was in the U.S.A. and killing people long before the 1980s… It was happening and all the same things were happening to people infected and nobody was able to figure it out because it hadn't been spread enough yet and by the time the people were dying from things like Pneumonia and other things, it was too late and most facilities either didn't have the technological resources to be able to identify HIV for what it was or the cause of death was identified as one of the opportunistic conditions or diseases that resulted from AIDS destroying their immune system.

  22. U cant tell me HIV wasn't a man made thing. I bet it was discovered trying to find a bio weapon or something similar and they found HIV and used it on test monkeys and god knows how it came in contact with humans

  23. Rockefellers are responsible for HIV. They own many virus. But humans believe monkeys and bugs give them diseases. Please. Bill Gates kills with his vaccines and that's a fact jack.

  24. I'm glad you showed this to me. I was told that some disgusting people had sex with chimpanzees. Could it have possibly? I mean no one is going to admit that the had sex with an animal, but there is such a thing called bestiality. Just wondering!

  25. The notion that HIV results originally from a jungle primate is a hypothesis. I agree that it is most likely, and plausible, but no one knows for sure. It could also have been the result of recombinant virus research, weapons of cultural war and atrocity commissioned by war criminals like Kissinger and that crowd of creeps, furthered and left unaddressed by Reagan. Again, I don't know, not arguing this hypothesis, just pointing out no one was there with a super 8 camera recording the first transmission; we don't know.

  26. Apologist for the drug companies. No mention about the Oral Polio Vaccine tests in Africa that used monkey kidney tissue culture to grow live virus vaccines in the 50's. The very places that HIV arose in Africa were those places the OPV was tested. The three clades of HIV seem to correspond to the three different groups that were working independently. The drug companies will be liable for billions of dollars if they admit their part in the pandemic.

  27. HIV/AIDS is man made virus. It was an engineered virus by the United States government as a population control.

  28. I find it hard to sympathize with people who have tons of sex with randos then are surprised when they get an std.

  29. There's also a Cat variant of HIV as well, would be interesting to do a video of that too.

  30. I don’t think the infected blood got into the human’s small cut. I think they did something else if you know what I mean… 😏

  31. 100% PROOF HIV cures have existed for decades.see ""Dr Sam Chachoua Treatment For Aids,Cancer and Heart Disease" AIDs is all about greed$$$$ and Satanism (depop).

  32. HiV is a fragile virus. It could be killed easily with multiple different treatments. Kill it by the layers. Skin, blood, body cavities, bone. Slowly and gently. Use ART to decrease the coral load. Then use things such as HD and peritoneal dialysis. Then use IO and trickle medication into bone marrow. I think its unfortunate more things have not been done to treat thos medical condition. You would have millions of potential organ donors if you had a treatment to cure while you are waiting for a vaccine and medication to cure. There is definitely more that can be done for these people. That is my personal opinion.

  33. At this point it doesn't matter how it was started. What matters is its being spread to very innocent people. And straight white females take all the stigma and torture being exposed to stuff, when all they want is a nice guy. So something has to change.

  34. Despite what is constantly said, the theory that Koprowski's oral polio vaccine was the source of HIV has NOT be refuted.
    Nor has it been conclusively demonstrated.

  35. Everyone here please look up Peter duesberg, the microbiologist who goes over the evidence, or lack thereof, of how HIV was never isolated, and him and anyone else who simply mentioned this were immediately censored, defunded, careers attempted to be ended- (many times successfully), and totally abused simply for sighting their own data which overtly conflicted w the HIV CAUSES AIDS HYPOTHESIS: THIS IS STRICTLY HOW PEOPLE WHO HAVE SOMETHING TO HIDE & ARE PROBABLY GUILTY ACT


  37. Please, I beg of you to stop staring into my soul and for gods sake blink and hydrate your eyes 😭😭😭

  38. So a disease this deadly, only just recently gained the ability to crossover to infecting humans.

    This is a disease wherein monkeys and certain people in Africa have HIV-2, which you can live with.

    We've known about most other STDs for centuries, documented clearly in the history books. To make that kind of interspecies jump takes 100s of years at least, and the symptoms of HIV/AIDS are very distinctive to that disease.

    On another line, the USSR was investigating bio weapons in Africa in the 1950s, the first recorded case of HIV in America was in the 50s, bearing in mind both the US and USSR had double agents planted in each other's countries.

    It's not a stretch to realise that US agents could have stolen the virus/bioweapon and then subsequently used it on US minorities who were causing unrest.

    It wouldn't be the first time that the FBI and/or CIA have aggressively sought to repress minority groups who were becoming a problem.

  39. i dont know if anyone will respond to my comment but i dont knnow who else to ask . My Friend first year med school student cut his thumb with scalpel while dealin with a cadaver. She went to the emergency care and the nurse told him that he may contact HIV or hepatitis because of this . They took his blood samples and results are yet to come ?? i know dont know how to help my friend deal with this . Any help????

  40. The only cure for this disease is firing squad. Think about it, if the army arrest those infected people and execute them the world will be safe again.

  41. This dude is amazing, I don't think I've ever seen a more informative helpful videi about HIV and AIDS. Thank you.

  42. Oh yah… God did put a price onto all the free and carefree screwing each other to death orgies of the 70's. The cost… YOUR LIFE!

  43. I remember watching Newtons Apple on PBS in the early nineties and they stated there will never be a cure.

  44. Hmm chimps are adware species!. Full of HIV or the begging of it. But although the species chimp are less than humans and it is a sexual pass on then why are chimps OK and humans are still ding of it? And chimps are3 times stronger than a human male ? A human cannot havecsex with a female chimp. She would rip his arms off!!!!

  45. This is a FALSE statement .Aids has a patent on it. It was created in a laboratory by racist scientists geared toward killing black people.

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