After reading many articles about why AIDS is transmitted from orangutans to people, I think it is necessary to understand the origin of AIDS and learn from Luo.
The first discovery of HIV in the United States
People sometimes say that HIV started in the United States in the 1980s, but in fact, this is only the first time that human beings have recognized HIV and formally recognized it as a new health risk.
198 1 year, some rare cases of diseases were found among gay men in new york and California, such as Kaposi's sarcoma (a rare cancer) and a lung infection called PCP.
No one knows why these cancers and opportunistic infections spread, but they think it may be caused by an infectious disease.
At first, the disease was given various names related to homosexuality. It was not until the middle of 1982 that scientists realized that this "disease" also spread among other people, such as hemophiliacs and heroin addicts. By September of that year, this "disease" was finally named AIDS.
It was not until 1983 that the researchers of Pasteur Institute in France isolated and identified this HIV virus. This virus was originally called Lymphadenopathy Associated Virus (LAV), and scientists from the National Cancer Institute of the United States also isolated this virus and named it HTLV-III (later admitted that LAV and HTLV-III are the same).
In the same year, the Centers for Disease Control (CDC) listed the main high-risk groups, including AIDS partners, injecting drug users, hemophiliacs and people who have been to Haiti recently.
When AIDS cases began to appear in the United States, people's panic and shame about the epidemic intensified due to the lack of accurate information about HIV and its connection with AIDS.
Soon, people began to talk about a 4-H club with AIDS risk: homosexuals, hemophiliacs, heroin addicts and Haitians, which further deepened people's sense of shame about the club.
While being afraid of AIDS, people try to find a solution. Since then, the research on AIDS has never stopped. Later, it was confirmed that HIV came from monkeys.
Why does HIV come from monkeys?
1999, researchers discovered a SIV (called SIVcpz) in chimpanzees, which is almost the same as the HIV virus in humans (mainly attacking the immune system).
The researchers who discovered this connection then concluded that chimpanzees were the source of HIV- 1, and the virus spread from chimpanzees to humans at some point.
Subsequently, scientists did a lot of research on how SIV of chimpanzees developed. They found that the prey eaten by chimpanzees was the main reason.
Chimpanzees prey on red-crowned cranes and spotted-nosed monkeys. These monkeys infected chimpanzees with two different SIV viruses, which was completely resisted by the hunted.
Then the two SIV viruses combined to form a third virus (SIVcpz), which infected them and spread them to other chimpanzees (SIVcpz can even infect humans).
The same fate happened to humans, this time chimpanzees played the role of prey, but the virus spread to humans in the same way.
How is HIV transmitted from chimpanzees to humans?
In fact, many people are concerned about how AIDS spreads from black bears to humans. Considering that the main mode of transmission of AIDS is sexual transmission, many people have illusions.
In fact, any species has a very strong sense of self-protection for their own territory, and there can be no promiscuity. Even if someone agrees, chimpanzees will not agree.
Now, the most accepted theory is the "hunting" theory. The main reason why SIVcpz was transferred to humans was that chimpanzees were killed and eaten by local hunters, or their blood entered human wounds during hunting.
Under normal circumstances, the hunter's body will resist SIV, but in a few cases, the virus will adapt itself in a new human host and become HIV- 1.
There are four groups of HIV virus (M, N, O, P), and the genetic composition of each group is slightly different. This supports the hunting theory, because whenever SIV spreads from chimpanzees to humans, it develops in a slightly different way and produces slightly different strains. This also explains why HIV- 1.6 has more than one strain.
At present, the most studied HIV virus strain is HIV- 1 M group, which has spread all over the world and is also the vast majority of HIV infected people today.
And HIV-2 comes from SIVsmm of black monkeys, not chimpanzees. This cross-species transmission is thought to occur in a similar way (by hunting and eating monkey meat).
It is rarer and less contagious than HIV- 1. Therefore, there are far fewer people infected with HIV-2 virus, mainly distributed in several countries in West Africa, such as Mali, Mauritania, Nigeria and Sierra Leone.
How is AIDS spread?
In many early cases, the death cases caused by common opportunistic infections show that it is probably related to HIV, but there is no blood sample.
The first confirmed case of HIV came from a blood sample of a man 1959 living in Kinshasa, Democratic Republic of Congo. The samples were analyzed retrospectively and tested for HIV.
Using the earliest known HIV samples, scientists have been able to create a "family tree" of HIV transmission, so that they can discover the origin of HIV.
Their research concluded that SIV first spread among humans in the Democratic Republic of Congo and Kinshasa (the largest HIV strain in the world) about 1920.
Kinshasa is the capital of the Democratic Republic of Congo, the largest river port and the largest city in Central Africa. The traffic in the surrounding areas is very developed, with roads, railways and rivers.
Large-scale migration and sex trade can explain how HIV spreads along these infrastructure routes. Arrived at 1937 and arrived at Brazzaville, about 120 km west of Kinshasa.
By 1980, half of the infected cases in the Democratic Republic of Congo occurred outside Kinshasa, which reflected the growing epidemic situation.
In 1960s, subtype B (subtype M) of HIV- 1 spread to Haiti. At that time, many Haitian professionals who worked in the colonial Democratic Republic of the Congo in the 1960s returned to Haiti. At first, they were accused of being responsible for the AIDS epidemic, so they suffered serious racism, humiliation and discrimination.
HIV- 1M subtype is the most widely spread subtype of HIV in the world. By 20 14, this subtype has infected 75 million people.
finally
As of March 3, 2065438, there were 7896 cases of AIDS and AIDS-infected people in China, with 245498 deaths reported.
At present, the number of AIDS patients in China is increasing every year, so it is better to lead an honest and clean life. After all, there is no treatment yet.
I am the author of Baidu Know Daily-Blame Lokp, and I am glad to answer this question!