AIDS is an infectious disease caused by a virus called "HIV". To date, despite its suspensive efficacy, the treatment has not allowed a definitive cure of the disease. Only preventive and protective measures are effective in avoiding contamination.
Words for ailments
AIDS is an acronym for "Acquired Immunodeficiency Syndrome". This is the most advanced phase of infection with HIV, the "Human Immunodeficiency Virus".
"Triple therapy" refers to a set of three drugs which are given to decrease the amount of HIV virus in the body. If a fourth drug is added, we will speak of quadruple therapy.
The "viral load" is a very precise estimate of the amount of virus circulating in the body.
What is HIV?
"HIV", or "Human Immunodeficiency Virus", is a virus that belongs to the "retrovirus" family. It is found exclusively in humans. When you become infected with HIV, it builds up in the body and gradually destroys the white blood cells that are responsible for defending the body against infection.
We speak of "AIDS", or "Acquired Immunodeficiency Syndrome", when the first "opportunistic diseases" (infections and tumors) appear. These opportunistic conditions are diseases which would not have occurred if the white blood cells of the immune system had not been affected and which only develop in immunocompromised patients. <Brtwo different strains of HIV: HIV-1 is the most common and present all over the world and HIV-2 is mainly present in West Africa..
What are the peculiarities of HIV?
The major peculiarity of HIV is its original ability to infect cells of the immune system (lymphocyte-like white blood cells).
Thanks to receptors on the surface of its envelope, the virus will penetrate inside a white blood cell, called a "CD4 + lymphocyte" (or "helper lymphocyte"). Then HIV will integrate its DNA into that of the cell by a complex mechanism, the purpose of which is to make the cell itself manufacture virus clones. Then the virus clones that have been created will come out of the lymphocyte, destroying it to infect another, and so on, until all the CD4 + lymphocytes are destroyed if nothing is done.
This replication will last several years and will be less and less controlled by the immune system, whose number of CD4 + lymphocytes will fall inexorably. <Brse nesting in the deepest recesses of the body ("niches") to constitute "reservoirs" difficult to access treatment and the immune system, which complicates complete eradication of the virus and permanent cure. Current treatments therefore only allow "treatment remission".
How do you get HIV?
HIV is a fragile virus that only survives a very short time in ambient air, so it always needs a man, its only "host", to survive. Therefore, to catch the virus, it is necessary to have close contact with the exchange of bodily fluids (semen, blood, vaginal secretions, etc.) from a patient with a significant viral load to a healthy subject.
There are 3 ways to catch the AIDS virus: sexually, through the blood and from mother to child.
The sexual route accounts for nearly 90% of infections because the virus is found in large quantities in the semen and vaginal secretions of infected people. Heterosexual relations, like homosexuals, are therefore concerned, but the transmission is all the more important when the mucous membrane is altered ("co-infection") or the sexual relations are more "traumatic". The mucous membranes of the sexual organs are very thin and highly vascular, which facilitates transmission. Other types of practices such as anal intercourse are more risky because of their traumatic nature and the thin wall of the rectum.It should be noted that the risk of transmission from an infected patient who is treated and whose quantity of virus in the body is undetectable, remains non-negligible: about 8%.
Blood transmission is rare in the general population since it only concerns specific situations: occupational accidents of nursing staff with blood products or contaminated objects (needles, scalpels), and syringe exchanges among HIV-positive drug addicts. The risk of contamination varies depending on the situation but, for example during a blood exposure accident, it is estimated at 0.3%.
Mother-to-child transmission should not be overlooked. The newborn can be infected at the end of pregnancy, during childbirth, during passage through the vagina, but also during breastfeeding. It is also possible to see contamination by the placenta. These risks are reduced when the mother is on antiviral treatment and also during a cesarean delivery.
HIV is not spread through a handshake, a kiss, sweat, clothing, or food.
How to diagnose HIV?
A person is said to be "HIV positive" when they have antibodies in their body against a pathogen. This means that person has already come into contact with the pathogen, and has made antibodies, either because they declared the disease or because they were vaccinated against it.
Therefore, for a person with AIDS, it should rather be said that he is "HIV positive" in order to be fairer. You can be HIV positive for the hepatitis B virus, for example. However, the use of the term "HIV positive" in isolation has passed into everyday language, so it is not incorrect to use it.
What are the signs of HIV infection and AIDS?
HIV infection breaks down into three main phases, which correspond to the development of the virus in the body and the gradual destruction of lymphocytes in the immune system.
The first phase is what is called the "primary infection". This is the period immediately after contamination. It begins with an incubation period of about two weeks during which there is no sign. Then it can manifest itself as a flu-like syndrome in 50% of cases or remain without any signs ("asymptomatic"). Fever, body aches, pharyngitis, lymph nodes or diarrhea can be observed for a few days. These signs are not very specific for the disease and are rarely reported with possible HIV infection.
The disease will then enter its chronicization phase which will last for several decades and which varies greatly from person to person. The virus will then multiply significantly in the body and gradually destroy the CD4 + lymphocytes which will nevertheless be partially renewed. Clinical signs may appear sparingly and more often after a few years. They are dominated by damage to the skin and mucous membranes, such as "seborrheic dermatitis", "oral fungus", "infections of the hair follicles", "condylomas" and various growths. Associated with this, episodes of fever can occur, as can night sweats and diarrhea. At this stage, the risk of partner contamination is very high.
Finally, the third phase of the disease is AIDS itself. It starts from the moment the first opportunistic disease appears. This means that the CD4 lymphocyte count is very low and the immune system can no longer control the infection or prevent the onset of an opportunistic disease. Among the many possible opportunistic diseases, we find pulmonary infections (tuberculosis, pneumocystosis…), cancers (lymphomas…) and neurological damage (cerebral toxoplasmosis, encephalopathy…). All of these attacks are serious and potentially fatal.
This clinical picture only concerns infections that have not yet been treated with appropriate treatment. Thanks to the progress of triple therapies, and if the infection is diagnosed early, the entry into the AIDS phase can be postponed by several decades.
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