Wen Brain Cave Jun
In August, Brain Dongjun went to participate in a Liuzhou disease control anti-AIDS research project and came into close contact with these patients in the "extreme zone".
Contrary to what we might think, most patients are not as decadent as expected and look no different from normal people. They go grocery shopping with their wives, rub mahjong with neighbors, pick up their grandchildren to school, and come to the hospital to get medicine (free antivirals) as naturally as it is for each of us to go to a community health center next door to see a small cold.
However, as we all know, under the surface calm, there is a time bomb buried. Last week, a local colleague said on WeChat that the uncle who picked up his grandson to school every day was gone
Since the discovery of HIV, the human immunodeficiency virus, it has caused an unprecedented number of cases of illness and death.
According to statistics, in 2017, the number of people infected with AIDS worldwide has reached 37 million, and there are nearly 2 million new cases every year.
Even though there are multiple antiviral drugs available today, the virus is still spreading around without hesitation.
The topic of AIDS is mostly about how to prevent AIDS, there have been many scientific and pertinent opinions, this is a disease that can no longer be shaken off once it is on it, everyone should keep twelve points sober, how can not be excessive.
Today we will talk about the origin of AIDS from another perspective, trying to unravel the inextricable connection between human beings and this appalling disease from a historical and evolutionary perspective.
<h1>One or two monkey viruses are "mixed" in chimpanzees</h1>
Although it is generally believed that the source of human immunodeficiency virus infection first appeared sometime in the 1980s, in fact, the story began earlier.
The two species of monkeys involved in Central Africa are called the Great White-nosed Long-tailed Monkey and the Red-crowned White-browed Monkey. The former has a large white nose and the latter has a pinch of red hair on the top of the head.
Aside from these commonplace appearances, these two monkeys don't really look like they have three heads and six arms, and it's hard to imagine that they are the real culprits behind the AIDS pandemic.
The most crucial reason is that these two monkeys have two things in common:
The first common denominator is that they are all naturally infected with the monkey immunodeficiency virus, abbreviated as SIV. Each monkey possesses a variant of the virus. It may be that their ancestors carried the virus for millions of years, so they didn't get sick if they got it.
Because after millions of years of evolution, their immune systems have been able to live in peace with the virus. (See Why can't humans fight HIV?) It turned out to be the "curse" of evolution).
Another thing they have in common is that they are all considered delicacies by chimpanzees.
During the hunt, the microorganisms carried by the prey can enter the hunter's body without reservation. This is the perfect preparation for chimpanzees to infect SIV in these two monkeys.
When a hapless chimpanzee, we can call it "Patient Zero," accidentally captures a white-nosed long-tailed monkey or a red-topped white-browed monkey, and the SIV strain of the monkey is transmitted to the chimpanzee. The chimpanzees then captured another of the two monkeys and infected another strain of SIV.
The two strains of the virus meet in chimpanzees, and immediately genetic exchange and recombination begin to occur, followed by the birth of mixed-race offspring, who also have genetic fragments of both parents, which scientists call "mosaic" viruses.
This "mosaic virus" is more powerful than its parent monkey immunodeficiency virus, which can cause chimpanzees to develop "AIDS" symptoms and soon began to spread widely through chimpanzee populations.
This is the origin of the infamous HIV.
<h1>HIV "jumps" from chimpanzees to humans</h1>
Sometime in the late 19th century and early 20th century, a hunter who lived on the edge of the jungle in Central Africa hunted down a chimpanzee.
The chimpanzee happened to be infected with HIV, so the virus successfully spread from the virus in the chimpanzee to the human body, becoming a veritable "human-acquired immunodeficiency virus".
Chimpanzees are the closest to humans, and there are data available that about 8 million years ago, humans and chimpanzees, as well as another chimpanzee called Bonobo, were one family, that is, they had a common ancestor. Therefore, some scientists call humans "the third kind of chimpanzees".
Because the blood is too close, the HIV that makes chimpanzees sick is transmitted to humans, and it can also cause humans to have severe symptoms of "AIDS".
<h1>Third, the road to HIV "borrowing" transmission</h1>
But the jump from chimpanzees to humans is only the first step in the virus's advances, and it's a long way from spreading around the world and eventually creating a terrible epidemic.
Scientists believe that HIV should have jumped from chimpanzees to humans around 1900. But for a long time, HIV didn't make much of it, and it really stepped into the ranks of the epidemic and began to ravage the world in the 1980s.
Why? Because the previous spread is not smooth ~~~
We know that viruses cannot survive and reproduce on their own, and need to rely on continuous transmission between host individuals to survive, and if the transmission is not smooth, sooner or later there will only be a dead end.
HIV was initially infected by a few people living on the edge of a forest. After the first hunter became ill by hunting sick chimpanzees, he infected several villagers on a small scale.
However, that's all there is to it. Because such small villages are isolated from the rest of the world, the virus has no chance to spread, and it is impossible to spread.
So why did it start to wreak havoc again?
Scientists have two conjectures, related to the two ways aids are transmitted, and we will talk about them:
1. The development of transport networks has contributed to the spread of AIDS
The first conjecture, scientists believe, is that the development of transportation networks has fueled the global spread of AIDS. This conjecture is based on the sexual transmission of AIDS.
They argue that in the mid-to-late 20th century, land transportation such as road and rail began to develop, giving the HIV virus the opportunity to extend directly from the depths of the jungle to the center of the city. With the construction of roads and railways, the virus can "ride" cars and trains to travel around the world.
Scientists have shown that proximity to roads increases the risk of HIV infection in people. The more roads you travel, the more likely you are to be infected with AIDS. Because roads send people in all directions, they take the virus in all directions.
In addition to sex workers, the most popular occupation for AIDS in sub-Saharan Africa is truck driver.
The same is true for rail planes. However, with regard to railways, some scientists have other ideas, they believe that the construction of railways in all directions has also created conditions for the spread of AIDS.
Many male laborers were recruited to build railroads everywhere. Construction sites where only adult male workers live are well suited to the spread of sexually transmitted viruses like HIV.
2. The promotion of cheap syringes has fueled the AIDS pandemic
The second conjecture is related to the bloodstream route of AIDS. Scientists believe that the spread of AIDS is inseparable from the promotion of cheap syringes. Because the timing of the global spread of HIV coincides with the large-scale roll-out of cheap syringes.
Until the 1950s, syringes were handmade and expensive. However, around the 1950s, people began to mass-produce glass and metal syringes with machines. After the 1960s, there were disposable plastic syringes. The cost of syringes has dropped dramatically.
On the other hand, science is changing rapidly, and the development of drugs and vaccines is also in full swing. The massive health campaign everywhere has indeed blocked the progress of many diseases.
But early, large-scale sanitation campaigns often vaccinated thousands of people with the same unpasteurized needle. If one of them is living with HIV, the people who share the needle with him are also at risk.
Scientists believe that AIDS officially broke out in this situation.
No matter which conjecture is correct, or whether the two are inherently complementary, no one can be separated.
Everything has two sides, the development of human society at the same time, but also let the aids like the epidemic raging, we in the pursuit of economic and technological progress but also buried a lot of unpredictable hidden dangers.
And what we as small individuals can do in this irreversible process is indeed limited, only to return to the topic of HIV/AIDS prevention, to protect their own safety, to maintain their own health, how can not be exaggerated.
Be knowledgeable and healthier. Healthy new brain hole, I wish everyone beautiful (handsome) and healthy!
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