Tuesday, May 24, 2022

Where Did Hiv Come From

Homeless People And Intravenous Drug Users In New York

Where did Aids come from?

A volunteer social worker called Betty Williams, a Quaker who worked with the homeless in New York from the seventies and early eighties onwards, has talked about people at that time whose death would be labelled as “junkie flu” or “the dwindles”. In an interview for the Act Up Oral History Project in 2008, she said: “Of course, the horror stories came, mainly concerning women who were injection-drug users … who had PCP pneumonia , and were told that they just had bronchitis.” She continues: “I actually believe that AIDS kind of existed among this group of people first, because if you look back, there was something called junkie pneumonia, there was something called the dwindles that addicts got, and I think this was another early AIDS population way too helpless to ever do anything for themselves on their own behalf.”

Julia Epstein writes in her book Altered Conditions: Disease, Medicine and Storytelling that: “As we uncover more of the early history of HIV infection, it becomes clear that by at least the 1970s the virus was already making major inroads into the immune systems of a number of diverse populations in the United States and had for some time been causing devastation in several countries in Africa.”

Genetic Sequencing Confirms Geographical Origin

In order to determine this, the scientists compared the genetic diversity of viruses found in the Congo Basin, including the DRC and Cameroon. What they were able to determine was that, using the genetic clues and historical data, the outbreak did not start in Cameroon as previously thought, but was a result of the spread of the virus between Kinshasa and Cameroon as a result of river trade.

The investigators ultimately confirmed that the virus found in Kinshasa exhibited more HIV-1 genetic diversity than anywhere elseresulting from the spread of the rapidly mutating virus from person to personas well as the oldest known HIV-1 genetic sequences.

From the 1920s to the 1950s, rapid urbanization and the development of railways made Kinshasa a transport capital, thereby allowing the spread of HIV-1 throughout the country and soon after to East and Southern Africa. The genetic footprint left during this period illustrated dissemination of the virus throughout the DRC as people traveled on railways and along waterways to the cities of Mbuji-Mayi and Lubumbashi in the south and Kisangani in the north.

Between the 1950s and 1960s, the use of unsterilized hypodermic needles in sexually transmissible diseases clinics and the growth of commercial sex trade were among the factors for the rapid spread of the viruses, particularly in mining communities where there was a high migratory workforce.

How Did Hiv Spread From Kinshasa

The area around Kinshasa is full of transport links, such as roads, railways and rivers. The area also had a growing sex trade around the time that HIV began to spread. The high population of migrants and sex trade might explain how HIV spread along these infrastructure routes. By 1937, it had reached Brazzaville, about 120km west of Kinshasa.

The lack of transport routes into the North and East of the country accounts for the significantly fewer reports of infections there at the time.11

By 1980, half of all infections in DR Congo were in locations outside of the Kinshasa area, reflecting the growing epidemic.12

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Why Is Haiti Significant

In the 1960s, the ‘B’ subtype of HIV-1 had made its way to Haiti. At this time, many Haitian professionals who were working in the colonial Democratic Republic of Congo during the 1960s returned to Haiti.13 Initially, they were blamed for being responsible for the HIV epidemic, and suffered severe racism, stigma and discrimination as a result.

HIV-1 subtype M is now the most geographically spread subtype of HIV internationally. By 2014, this subtype had caused 75 million infections.14

Hiv And Aids: An Origin Story

Where Did HIV Come From

When HIV first began infecting humans in the 1970s, scientists were unaware of its existence. Now, more than 35 million people across the globe live with HIV/AIDS. The medical community, politicians and support organizations have made incredible progress in the fight against this formerly unknown and heavily stigmatized virus. Infection rates have fallen or stabilized in many countries across the world, but we have a long way to go.

Image via aids.gov. The WHO estimates that 97 percent of the world’s HIV positive population lives in low income nations where anti-viral treatments are scarce or unavailable.

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Groups And Subtypes Of Hiv

Genetic studies have led to a general classification system for HIV that is primarily based on the degree of similarity in viral gene sequence. The two major classes of HIV are HIV-1 and HIV-2. HIV-1 is divided into three groups, known as group M , group O , and group N . Worldwide, HIV-1 group M causes the majority of HIV infections, and it is further subdivided into subtypes A through K, which differ in expression of viral genes, virulence, and mechanisms of transmission. In addition, some subtypes combine with one another to create recombinant subtypes. HIV-1 group M subtype B is the virus that spread from Africa to Haiti and eventually to the United States. Pandemic forms of subtype B are found in North and South America, Europe, Japan, and Australia. Subtypes A, C, and D are found in sub-Saharan Africa, although subtypes A and C are also found in Asia and some other parts of the world. Most other subtypes of group M are generally located in specific regions of Africa, South America, or Central America.

In 2009 a new strain of HIV-1 was discovered in a woman from Cameroon. The virus was closely related to a strain of SIV found in wild gorillas. Researchers placed the new virus into its own group, HIV-1 group P, because it was unique from all other types of HIV-1. It was unclear whether the newly identified virus causes disease in humans.

The Aids Epidemic Arises

Though HIV arrived in the United States around 1970, it didnt come to the publics attention until the early 1980s.

In 1981, the Centers for Disease Control and Prevention published a report about five previously healthy homosexual men becoming infected with Pneumocystis pneumonia, which is caused by the normally harmless fungus Pneumocystis jirovecii. This type of pneumonia, the CDC noted, almost never affects people with uncompromised immune systems.

The following year, The New York Times published an alarming article about the new immune system disorder, which, by that time, had affected 335 people, killing 136 of them. Because the disease appeared to affect mostly homosexual men, officials initially called it gay-related immune deficiency, or GRID.

Though the CDC discovered all major routes of the diseases transmissionas well as that female partners of AIDS-positive men could be infectedin 1983, the public considered AIDS a gay disease. It was even called the gay plague for many years after.

In September of 1982, the CDC used the term AIDS to describe the disease for the first time. By the end of the year, AIDS cases were also reported in a number of European countries.

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Causes Of Hiv Infection

HIV is found in the body fluids of an infected person. This includes semen, vaginal and anal fluids, blood and breast milk.

It’s a fragile virus and does not survive outside the body for long.

HIV cannot be transmitted through sweat, urine or saliva.

The most common way of getting HIV in the UK is through having anal or vaginal sex without a condom.

Other ways of getting HIV include:

  • sharing needles, syringes or other injecting equipment
  • transmission from mother to baby during pregnancy, birth or breastfeeding

The chance of getting HIV through oral sex is very low and will be dependent on many things, such as whether you receive or give oral sex and the oral hygiene of the person giving the oral sex.

Did Hiv Come From Monkeys

New documentary explores the truth behind the origin and rise of HIV/AIDS | Your Morning

In 1999, researchers found a strain of SIV in a chimpanzee that was almost identical to HIV in humans.

The researchers who discovered this connection concluded that it proved chimpanzees were the source of HIV-1, and that the virus had at some point crossed species from chimps to humans.3

The same scientists then conducted more research into how SIV could have developed in the chimps. They discovered that the chimps had hunted and eaten two smaller species of monkeys . These smaller monkeys infected the chimps with two different strains of SIV.

The two different SIV strains then joined together to form a third virus that could be passed on to other chimps. This is the strain that can also infect humans.4

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Symptoms Of Hiv Infection

Most people experience a short flu-like illness 2 to 6 weeks after HIV infection, which lasts for a week or 2.

After these symptoms disappear, HIV may not cause any symptoms for many years, although the virus continues to damage your immune system.

This means many people with HIV do not know they’re infected.

Anyone who thinks they could have HIV should get tested.

Some people are advised to have regular tests as they’re at particularly high risk.

Case Definition For Epidemiological Surveillance

According to a study published in the Proceedings of the National Academy of Sciences in 2008, a team led by Robert Shafer at Stanford University School of Medicine has discovered that the gray mouse lemur has an endogenouslentivirus in its genetic makeup. This suggests that lentiviruses have existed for at least 14 million years, much longer than the currently known existence of HIV. In addition, the time frame falls in the period when Madagascar was still connected to what is now the African continent the said lemurs later developed immunity to the virus strain and survived an era when the lentivirus was widespread among other mammals. The study is being hailed as crucial, because it fills the blanks in the origin of the virus, as well as in its evolution, and may be important in the development of new antiviral drugs.

In 2010, researchers reported that SIV had infected monkeys in Bioko for at least 32,000 years. Previous to this time, it was thought that SIV infection in monkeys had happened over the past few hundred years. Scientists estimated that it would take a similar amount of time before humans adapted naturally to HIV infection in the way monkeys in Africa have adapted to SIV and not suffer any harm from the infection.

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Epidemiology Of Hiv And Aids

Epidemiology is the study of how disease is distributed in populations and the factors that influence the distribution. Epidemiologists try to discover why a disease develops in some people and not in others. Clinically, AIDS was first recognized in the United States in 1981. In 1983 HIV was discovered to be the cause of AIDS. Since then, the number of AIDS cases has continued to increase both in the United States and in other countries.

HIV and AIDS cases are reportable each state has its own laws and healthcare workers must be familiar with those of the state in which they are licensed.

The discovery of combination antiviral drug therapies in 1996 resulted in a dramatic in the number of deaths due to AIDS among people given the drug therapies. On the down side, many people who have access to the therapies may not benefit from them or may not be able to tolerate the side effects. The medications are expensive and require strict dosing schedules. Furthermore, in developing countries many people with HIV have no access to the newer drug therapies.

CDC estimates that that there are only 4 transmissions per year for every 100 people living with HIV in the United States, which means that at least 95% of people living with HIV do not transmit the virus to anyone else. This represents an 89% decline in the transmission rate since the mid-1980s, reflecting the combined impact of testing, prevention counseling, and treatment efforts targeted to those living with HIV infection .

Why Do We Care Does All This Research Into How The Virus Got Started Tell Us Anything About How To Stop It

PPT

Hunting chimps in West Central Africa.

Research into the HIV’s origins may eventually yield practical results. It could help scientists understand why HIV’s viral ancestor, SIV, doesn’t kill or even sicken chimps who carry it. With that knowledge, researchers might be able to make drugs with fewer side effects, or broad-spectrum vaccines that protect against all the strains of the disease that infect people today.

Korber suggests that in an era of emerging diseases, looking back on the virus’ shadowy origins offers a “history lesson,” or perhaps even a fable, with a moral attached. By the time doctors realized that HIV/AIDS existed, it had already taken up permanent residence in humans. They couldn’t have known about it before then, but, Korber says, at least now they know to be wary as the virus continues its shape-shifting spread around the globe. “The fact that it could be with us for quite a long time before we even realized it was there is kind of eye-opening,” she says. “I think it’s something to keep us on our toes. It helps us understand that we can be surprised.” And of course, HIV research may have a few surprises left for us, too.

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Samples Collected From Wildlife In Thailand

While its true that most emerging diseases affecting humans come from wildlife, its often human behavior that is to blame for the spillover. Humans are tearing down forests and hunting, eating, and selling wild animals at unprecedented rates. Each exotic animal shipped across the ocean to be sold as a pet is an sveacasino opportunity for a new pathogen to take root in a new continent. Each tree ripped from its roots increases interactions between humans and wild animals, and thus the odds that viruses will find new populations to infect.

But the good news is: If were the ones causing the problem, were the ones who can stop it.

At EcoHealth Alliance, were striving toward a world where pandemics like the one caused by HIV/AIDS are a thing of the past. Join us.

We Know When What About How

There are a few different theories about how these viruses got into the population. The idea that humans copulated with primates and subsequently became infected tickles the fancy of some, but this idea is not taken seriously by experts in the field!

The simplest explanation is that humans came into contact with the blood or other secretions of infected primates which is perfectly plausible since, for example, sooty mangabeys were both kept as pets and slaughtered for bushmeat in West Africa, the same region that HIV-2 is most prevalent. It would be easy for infected bodily fluids to come into contact with broken skin during the butchering process.

Given the fact that medical resources are costly, it is plausible that during immunization programs in Africa, healthcare professionals would have , providing ample opportunity to spread infection through the population. This, coupled with an increase in international travel alongside sexual promiscuity and intravenous drug use, seems a logical explanation for the emergence of HIV.

Oral polio vaccine administration. Image credit: Julien Harneis, via Wikimedia Commons.

In sum, while it is difficult to definitively prove where HIV came from, we can make assertions based on the best available evidence. This evidence points to a simian origin, not the government. Everyone loves to hear about a good conspiracy theory, but it really does not add up here.

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Pathogenicity Of Siv In Non

In most non-human primate species, natural SIV infection does not cause a fatal disease . Comparison of the gene sequence of SIV with HIV should, therefore, give us information about the factors necessary to cause disease in humans. The factors that determine the virulence of HIV as compared to most SIVs are only now being elucidated. Non-human SIVs contain a nef gene that down-regulates CD3, CD4, and MHC class I expression most non-human SIVs, therefore, do not induce immunodeficiency the HIV-1nef gene, however, has lost its ability to down-regulate CD3, which results in the immune activation and apoptosis that is characteristic of chronic HIV infection.

In addition, a long-term survey of chimpanzees naturally infected with SIVcpz in Gombe, Tanzania found that, contrary to the previous paradigm, chimpanzees with SIVcpz infection do experience an increased mortality, and also suffer from a Human AIDS-like illness. SIV pathogenicity in wild animals could exist in other chimpanzee subspecies and other primate species as well, and stay unrecognized by lack of relevant long term studies.

How Many Times Would Siv Need To Be Introduced Into The Human Population In Order To Seed An Epidemic Of The Size That Became Apparent By The Early 1980s

Study Reveals Origins Of AIDS Pandemic: A ‘Perfect Storm’

Three groups of HIV-1 exist today – group M, group O and group N. While group M is diverse, groups O and N are not, and remain highly restricted in one location. HIV-2 has one clear group with a separate path of descent, from the form of SIV found in sooty mangabeys in West Africa. This genetic tree suggests four separate transfers to humans, a puzzlingly rare chain of events given the potentially frequent contact with chimps in Central Africa, and the dating of chimp to human virus transfer back to the 18th century or even earlier.

In the opinion of Daniel Law-Beer, an epidemiologist from the University of Oxford, a star-like geography of infection would need to have been established early on in the epidemic, otherwise chance extinction events in one village could have eliminated the new virus from the human population quickly. He estimates that at least 60% of SIV transfers were dead-end infections of this sort which may have flared and died in remote locations.

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Sir Robert May of Oxford University also suggested that it was quite plausible for many viral transfers to have remained confined in locations where local custom did not encourage mixing between populations in different villages.

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