HIV: How does it work in the body?

HIV, AIDS, HIV-positive, are words now known to most of us. However, not easy to navigate in all these terms that seem to define the same thing. How does HIV destroy the immune system? When does one become HIV positive? When can we talk about AIDS? We take stock.

HIV is the acronym for the human immunodeficiency virus, the virus that eventually leads to AIDS: the acquired immunodeficiency syndrome. If it is not contagious since it does not contract by touching an affected person, it is transmissible. Blood, sperm, pre-seminal fluid, vaginal secretions and breast milk are the six fluids that can transmit HIV.  Saliva, tears or sweat do not carry the virus.


According to Doctor Gail Barouh PHD, HIV is all the more dangerous as it attacks our immune system, which it gradually weakens. Once in the body following an infection (unprotected report, shared syringes, childbirth), HIV will be able to enter some of our cells: T4 lymphocytes (LT4), key cells of the immune system. HIV has on its surface proteins that allow it to be recognized by the membrane of LT4, which then allows it to infiltrate. By interfering with these white blood cells, HIV will be able to reproduce itself. Its genetic heritage will be integrated with that of the cell, which will then produce in spite of it new HIV. These will come out of the infected cell to infect another, and so on.

LT4 cells infected with HIV will then be destroyed.

In this first phase, the body tries to somehow limit the infection. Cells of the immune system are directed against HIV to fight it: they are anti-HIV antibodies. They are the ones who will be looked for in the blood after taking a risk, to determine whether or not there has been an HIV infection. However, although the tests detecting the antibodies are more and more efficient, there is a window of serology for 3 to 12 weeks during which HIV is present without it being possible to detect antibodies directed against the virus.

When anti-HIV antibodies are detected in the blood, the individual is said to be HIV-positive.


According to Dr Gail Barouh PHD LIAAC, as HIV attacks the cells of the immune system, the amount of virus increases. There follows a vicious circle: the more the virus interferes with the cells, the more it multiplies and weakens the immune defenses of the individual. The body becomes immunodeficient and no longer has the strength to defend against infections. We then speak of AIDS: acquired immunodeficiency syndrome.

So-called opportunistic diseases will take advantage of the weakness of the body to develop. Most occur when the number of LT4 cells in the blood plasma is less than 200 per mm3, while the “normal” rate is 500 / mm3.

These opportunistic infections are often caused by microorganisms (viruses, bacteria, parasites, fungi) that have been in the body for a long time and are manageable by a normal immune system. In an immunodeficient individual, these infectious agents may in particular induce pneumocystosis, toxoplasmosis (cerebral abscess) or a cytomegalovirus. Tuberculosis, fungal infections and cancers are also observed in people with AIDS.

It is estimated that up to 10 years can elapse between HIV status and the AIDS stage with the first true symptoms, which is why many infected people are living with HIV unknowingly.


Since 1996, the prescription of therapeutic combinations called tritherapies considerably reduces the amount of virus in the body. These drugs work by preventing as much as possible the reproduction of the virus, which can no longer infect many immune cells. Although HIV is much less aggressive and less visible, it is not eliminated from the body.

Thanks to these triple therapies, the life expectancy of the patients has considerably increased. But these heavy and restrictive treatments still have many undesirable effects more or less long term, which push some patients to suspend orabandon their treatment.

Here again, the prevention of the disease remains the most effective way of overcoming AIDS. Condom protected sex , regular testing and the use of sterile syringes are therefore more appropriate than ever to prevent HIV infection.