20 January 2014

HIV and AIDS: facts and myths

7 facts about HIV

Anna Kirikova, Mednovosti

Fact # 1
About how HIV turns into AIDSThe human immunodeficiency virus is a retrovirus that affects cells of the immune system.

It attacks T-helper cells (a type of lymphocytes) containing the CD4 protein, which play a key role in the formation of the immune response. If no treatment is carried out, HIV reproduces itself very quickly (at a rate of 10 to 100 billion new viruses per day), continuing to lead to cell death and reduce the body's resistance.

For several years, the destruction of cells passes unnoticed for a person. But when the level of CD4+ lymphocytes in the blood becomes less than 200 units per cubic millimeter, this leads to a severe course of opportunistic infections (infections that the immune system usually effectively copes with). A condition that has developed against the background of HIV infection and is characterized, among other things, by multiple opportunistic infections is called acquired immunodeficiency syndrome (AIDS).

It is worth noting that not every infection with the human immunodeficiency virus ends with the development of AIDS. At the same time, all people with diagnosed acquired immunodeficiency syndrome are infected with HIV.

However, not everyone agrees with the latter. Several initially unrelated individuals, unrecognized by the scientific community, believe that the relationship between HIV infection and AIDS is questionable. The movement of deniers has no unified theory: some activists are not sure about the existence of the virus itself, others consider it harmless, and others regard AIDS as a non-communicable disease. Such ideas are criticized as baseless, speculative and antisocial. At the same time, their harm to society is obvious. Suffice it to mention that the policy pursued by the ninth President of South Africa, Thabo Mbeki, who actively denied the viral nature of AIDS, entailed at least 365,000 victims who failed to receive the necessary therapy due to government actions. Those who believed the activists of the movement and voluntarily refused therapy may be no less.

Fact # 2
About life expectancy with HIVDespite the fact that the human immunodeficiency virus can lead to the development of AIDS and, as a result, death, the average life expectancy of patients with HIV infection is almost the same as in healthy people.

One of the studies (the results were published in The British Medical Journal) showed that an infected person, who is currently 25, can expect to live up to 60 years with adequate treatment. According to another scientific work, the average life expectancy of those infected with HIV will be from 71 to 75 years.

Such comforting forecasts for residents of developed countries are not surprising, but the situation is similar in Africa. According to forecasts, the average Ugandan resident infected with HIV, but taking antiretroviral drugs, will live to 55 years.

However, it is not necessary to look into the future: already now a dangerous virus does not lead to an early death. The Washington Post publishes the story of a man living with HIV since 1978 and not experiencing any special problems, and The Sydney Morning Herald tells about a man who has been successfully fighting the disease for almost 30 years. These are far from the only cases of "longevity", which is possible, however, only with competent and timely therapy.

Fact # 3
About HIV and vaccinesAt the moment, there is no effective vaccine against HIV, but attempts to develop it are being made incessantly.

The main problem faced by scientists: it is unclear what exactly should be stimulated in the body to fight the virus in case of infection.

In the 2000s, under the auspices of the Ministry of Health of Thailand, clinical trials of a vaccine consisting of two substances that had previously been studied separately and did not show positive results were conducted. It was stated that the combination could reduce the risk of HIV infection by almost a third (31%), but the final product was recognized as not ready for use: as revealed by the final analysis of the data, the probability of a random result was 29%.

Clinical trials of the Merck vaccine, in which 3,000 volunteers participated, also proved to be a failure: it turned out that the use of the drug not only does not reduce the risk of HIV infection, but also increases it. The same fate befell another long-term American study.

However, failures do not stop scientists. Now the scientific community is discussing the possibility of creating medicines based on technologies that cured primates with the ape immunodeficiency virus (VIO), similar to HIV. Scientists have conducted several experiments by combining the genes of VIO and the genes of cytomegalovirus. The "mutant virus" allowed animal organisms to start producing antibodies that affect not only itself, but also the VIO. Unfortunately, the method helped only 9 out of 16 macaques studied, but the study of the technology will continue. Other researchers have been able to achieve similar success by mixing VIO with a large amount of Lactobacillus plantarum, a non–pathogenic bacterium to which the body is usually tolerant.

The possibility of creating a vaccine that affects the envelope protein of the virus, the atomic structure of which has become clear quite recently, is also being discussed.

Fact # 4
About cases of "healing"There are no known cases of healing from HIV infection: the disease is either fatal (in the AIDS stage) or chronic (with constant medication).

However, there were "exceptions".

Timothy Ray Brown, who is also called the "Berlin patient", improved his condition thanks to two bone marrow transplants from a donor who had innate immunity to HIV. This happened in 2007-2008. It is believed that cells with a gene mutation populated Timothy's immune system and allowed him to stop taking medications. However, the fact that the "Berlin patient" lives without antiretroviral therapy and does not experience health problems does not mean that HIV infection has been completely defeated. It is possible that the virus has been hiding and only significantly reduced its activity.

A patient from Trenton (USA, New Jersey) he was also able to stop taking medications, but for this he did not have to go through a complex and risky operation (mortality in bone marrow transplantation is 30%). Instead, the scientists worked with his own genes: the patient's leukocytes were affected by a special technology, thanks to which they began to produce a protein that destroys the CCR5 gene (a mutation of this gene makes people immune to HIV). The experiment turned out to be successful, and the infected person was able to do without therapy. But not everything is clear. Such manipulation of the genes of five other people did not lead to the expected result. Perhaps, experts suggest, every second CCR5 gene of a patient from Trenton could have an inherited mutation, which simplified the task.

There are other cases: scientists were able to rid the baby of HIV by starting aggressive antiretroviral therapy the day after his birth. The girl's treatment lasted 18 months, but was discontinued. Now, when the child is almost 3.5 years old, no traces of an active virus have been found in her blood. At the same time, not all researchers agree that complete and irreversible healing took place. Some scientists refer to the low effectiveness of HIV tests in people younger than 18 months (it is unclear whether the child was ill), others are sure that the virus is still present in the girl's body, and call the event "long-term remission" or "functional cure".

Their doubts are understandable. Not so long ago it became known that another experiment, allegedly leading to the cure of two patients, failed. Two patients from Boston, like Timothy Brown, underwent bone marrow transplantation (although from donors who did not have resistance to HIV). For some time they could do without taking antiretroviral drugs, however, according to the latest data, the disease still manifested.

Fact #5
About self-diagnosis of HIVThe traditional method of determining the presence of HIV infection is a blood test in the laboratory, but in the near future it will be possible to check yourself: using special kits for the study of saliva for the presence of antibodies.

France and the UK have officially allowed the sale of rapid HIV tests since 2014. In the USA, the analysis without involving laboratories was approved back in 2012.

It is worth noting separately that the FDA's permission and laws are valid only for instant tests from OraQuick – it is the technology used by the manufacturer that has been recognized as effective and trustworthy.

It is believed that the availability of the new product will contribute to an earlier diagnosis of infection, as well as help people who are embarrassed to do an analysis in a medical institution and are looking for anonymity. At the same time, the scientific community warns about the possible inaccuracy of express diagnostics. In addition, due to the widespread introduction of so-called self-tests, it will be more difficult to control the real number of infected people.

Fact # 6
About HIV and the lawsHIV infection is not only a medical concept, but also a legal one, since the human immunodeficiency virus is mentioned in many regulatory acts.

In addition to the fact that intentional and even unintentional HIV infection is a crime in most countries, there are or have been other laws related to the problem of HIV in one way or another/AIDS.

In particular, from 1987 until recently, people with HIV infection were prohibited from immigrating to the United States, and those foreigners who already lived in the country were asked to return home. The same ban has been introduced in a number of other countries. In some places it is still preserved. For example, if it is found that a foreigner who is in Russia is HIV-positive, he will be deported.

For a long time, British doctors who had HIV-positive status could not work as dentists, surgeons or midwives due to legal restrictions. However, the local authorities decided to lift this ban. Since 2014, HIV-infected doctors will be able to hold the above positions, provided they receive antiretroviral therapy and regularly visit their attending physician.

Another important amendment in the legislation was noted by the United States: President Obama allowed to conduct research on the safety of organ transplantation from donors with HIV (a ban on this has been in effect since the 1980s). It is assumed that after a number of studies, it will become clear how effective organ transplantation of some HIV-infected people is to others.

Other discriminatory laws are also being reviewed. But not everywhere. In the autumn of this year, a bill was submitted to the Chinese authorities prohibiting HIV-infected people from using public baths. Despite the active protests of scientists and international organizations, Chinese residents, oddly enough, support this bill.

Fact # 7
About HIV and prejudiceDespite the mass of reliable information in the media about HIV infection and AIDS, many people are not aware of the real state of affairs, and some ridiculous prejudices still exist.

A study conducted by the charity organization The National AIDS Trust in 2013 revealed that 46% of 12 thousand Britons surveyed are sure that you can "catch" HIV by accidentally stepping on a needle thrown in the park or getting spit from a stranger. What is not true is that infection is possible only during vaginal, anal and oral sex, when infected blood enters the bloodstream of a healthy person (for example, during the use of injecting drugs) and from mother to child (during childbirth and milk feeding). The transfer of the virus through a random injection is extremely rare: the risk of contracting HIV infection if a sick person used the needle is 0.3%. In addition, HIV will not last long in the environment, and a needle that has been lying on the street for some time is usually not dangerous.

Another survey conducted among two thousand students of higher educational institutions in Turkey in 2012 showed: 16% of respondents believe that HIV infection and AIDS are God's punishment for sins, 8% of respondents believe that proper nutrition and sports will protect them from the virus, and 9% are sure that a strong and passionate love is stronger than illness.

However, there is nothing surprising in the fact that ordinary people are subject to prejudice – many incorrect judgments were planted from the outside. For example, if you believe the documents published by American intelligence, the leadership of the USSR for a long time called HIV a biological weapon created by the enemy side, and purposefully sowed such views among the masses.

Portal "Eternal youth" http://vechnayamolodost.ru20.01.2014

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