What Is HIV / AIDS?

2023 Author: Wallace Forman | [email protected]. Last modified: 2023-08-25 11:04

HIV / AIDS: what is it?

HIV-1 and HIV-2 are lentiviruses from the retrovirus family. HIV-1 was first isolated from the lymphocytes of a haemophilia patient in 1983 by Luc Montagnier's working group at the Pasteur Institute in Paris, and this discovery was confirmed by other working groups a little later. The virus is infectious both as a free virus and in the human host cell. It can be transmitted from mother to child through sexual contact, blood-to-blood contact (e.g. by injection into a vein), mucosal contact with certain body fluids or during pregnancy…

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• Destruction of the body's defenses
• When does AIDS develop?
• The spread of HIV / AIDS
• HIV infections in Austria
• AIDS diseases in Austria
• High HIV test rates in Austria

Destruction of the body's defenses

When they come into contact with the mucous membrane, the HI viruses can transfer dendritic cells (e.g. special immune cells located in the skin) to CD4 + T lymphocytes and infect them. Direct blood contact can immediately lead to an infection of CD4 + T lymphocytes. These special body defense cells are located in the center of the immune system's network and are important for its control. They also protect us from diseases caused by pathogens that have often been in our body for a long time by suppressing them. If the CD4 + T lymphocytes are severely decimated by the HIV infection, these pathogens cause diseases and this is called AIDS. Modern serological test methods (combined HIV antibody antigen screening tests) enable diagnosis to be made just a few weeks after infection.

The immune deficiency (destruction of the body's defenses) HIV infections take very different courses from one individual to another. Diseases can, but need not, occur. There are often long periods between individual illnesses without physical complaints. Even a pronounced immunodeficiency can initially proceed without symptoms until the occurrence of the most serious illnesses.

The measurement of the viral load in untreated patients is often used to assess the expected progression of the immunodeficiency: the higher the viral load, the higher the risk of a more rapidly occurring immunodeficiency. The number of CD4 + T lymphocytes ("helper cells"), measured per microliter of blood, provides information about the current state of the immune system: the fewer helper lymphocytes, the more pronounced the immune deficiency.

When does AIDS develop?

If certain diseases occur with an immunodeficiency caused by HIV, one speaks of AIDS. These include, for example, Pneumocystis jiroveci pneumonia (PjP), a form of pneumonia or infectious diseases of other organs, such as the esophagus with the yeast Candida albicans. The most common tumors in connection with AIDS are cancers caused by viruses, for example Kaposi's sarcoma (skin tumor), which has become very rare today, or cervical cancer and lymphoma.

The spread of HIV / AIDS

The number of new HIV diagnoses peaked in 1996 with 3.5 million cases worldwide. Since then, the number of new infections diagnosed each year has decreased and was around 2.1 million in 2013. This decline is attributed to falling new infection rates in some countries in Asia, Latin America and Africa - regions with very high HIV prevalence. However, the African countries south of the equator remain hardest hit worldwide. At the same time, infection rates continue to rise, especially in Eastern Europe and Central Asia: Here, the number of people with documented HIV infection almost doubled between 2001 and 2013 - from 630,000 to 1.1 million.

The estimated number of AIDS deaths fell from 2.2 million in 2004 to 1.5 million in 2013, according to the WHO. The number of people living with HIV infection continues to rise worldwide, mainly because infected people survive longer: According to UNAIDS, there are almost 37 million HIV-infected people worldwide (as of the end of 2014) and an estimated 17 million HIV -Infected people who do not know anything about their HIV infection. However, only around 16 million people with HIV receive HIV therapy worldwide (as of June 2015). The WHO's goal by 2020 is to diagnose 90 percent of all HIV infections, to enable 90 percent of all HIV-infected people to undergo HIV therapy and to lower the virus in the blood below the detection limit in 90 percent of them through therapy.

For the latest information on the spread of HIV / AIDS, visit: www.unaids.org

HIV infections in Austria

According to estimates by the Austrian HIV cohort study ÖHIVKOS (seven Austrian treatment centers, covering over 70 percent of those infected with HIV treated in Austria), around 8,500 HIV-infected people live in this country (as of July 2015). The number of new HIV diagnoses in Austria has decreased significantly since 2011 and was around 300 to 400 in 2014. In 2014, 48 percent of newly diagnosed HIV-infected people were through homosexual contacts, 34 percent through heterosexual contacts and nine percent through sharing infected by injection material during intravenous drug use. Around 21 percent of the cases were found in women.

Around a third of those infected through heterosexual contact come from countries with a high HIV prevalence (the majority have probably already come to Austria with the infection). Around 17 percent of those infected through heterosexual contact became infected through sexual contact with people from high prevalence countries. Almost a third of those newly diagnosed are already in the late phase of the HIV infection and often already have AIDS.

AIDS diseases in Austria

According to the Federal Ministry for Health and Women, almost 4,000 people in Austria contracted AIDS between 1983 and 2012. Around half of those affected had died of the disease and its complications by the end of 2012. In 2012 there were around 1,800 people suffering from AIDS in Austria. Since 1995 - with the increasing use of more effective drugs - the number of AIDS diseases and deaths has steadily decreased.

For more information on the number of AIDS cases and AIDS deaths, see the AIDS statistics from the Ministry of Health.

High HIV test rates in Austria

Austria has one of the highest per capita rates of HIV tests in Europe. Nevertheless, in international comparison, HIV infection in Austria is not diagnosed more often in the early stage of infection and so almost a quarter of those affected already have an advanced immune deficiency (CD4 + T lymphocyte count less than 200 per Microliter). Carrying out the HIV test more specifically and consistently for so-called indicator diseases would be one way of diagnosing HIV infection in general earlier. This approach is strongly recommended in Europe.