The human immunodeficiency virus, or HIV, weakens the immune system. At an advanced stage, it makes the organism vulnerable to infection. It is transmitted through sexual or blood, or from the pregnant woman to her child.
In the absence of early detection and start-up of treatment, HIV infection evolves in several phases. The first phase does not cause any specific symptoms: it is the phase of asymptomatic HIV sero-positivity. The diagnosis of the disease is done through HIV serology.
Primary HIV INFECTION
The “primary infection” phase corresponds to the first contact with the virus. When a person is infected with HIV, in about half of the cases, clinical signs may occur during the month following contamination, most often referring to a flu-like syndrome:
- A fever of more than 38 °c;
- The appearance of lymph nodes;
- A rash of red plaques on the body and face;
- Headaches, stomach aches, muscle aches;
- diarrhea, vomiting.
These symptoms are not specific to HIV infection. Few HIV infections are diagnosed at this stage.
The chronic PHASE of HIV
After primary infection, the HIV-infected person does not experience any symptoms while the virus continues to develop in its organism.
The chronic phase asymptomatic.
This phase can last several years and since the onset of new treatments, it is longer. Even if it does not feel any symptoms, the infected person can transmit the virus.
The Chronic phase symptomatic
After the unsigned phase, symptoms testifying to the immune weakening appear:
+Moderate but persistent fever;
+An increase in lymph node volume;
For several years, HIV infection does not manifest itself. Then the disease appears. At its advanced stage, it can cause serious complications due to lower immune defenses. These are:
- Opportunistic infections caused by bacteria, fungi, viruses or pests most often harmless in people with normal immune defences;
- Cancers in particular of the immune system (lymphomas). A common cancer is Kaposi’s sarcoma, a condition characterized by its cutaneous impairment: presence of nodules (swelling hard and rounded under the skin), purplish plaques extending over the body…;
- Weight loss, in about 20% of people, can evolve into extreme slimming (wasting);
- In some cases (rarer since the onset of treatments), a brain injury, with progressive dementia.
The medical diagnosis of HIV INFECTION
Diagnosis of HIV infection is posed:
Either during a screening,
Or the onset of symptoms when it is later.
The diagnosis is done through a blood test that detects the presence of antibodies to HIV, from six weeks after the contamination. It’s HIV serology.
The laboratory test is the 4th generation Elisa assay that detects anti-VIH1 and anti-hiv2 antibodies and a virus antigen named P24.
If the test is positive, another test called Western-Blot looking for different antibodies is carried out to confirm the diagnosis. If the latter is negative, it is necessary to renew the exams a little later.
In case of suspicion of a very recent infection of less than 3 weeks, a direct search of the virus is possible.
Assessment of the stage of HIV infection
Additional tests are used to define what type of HIV is involved and to assess the stage of HIV infection.
An examination helps to quantify the importance of the multiplication of the virus in the organism. We are talking about the “viral load”.
Similarly, it is possible to measure the number of CD4 T lymphocytes in the blood:
- The normal rate of CD4 T lymphocytes is between 600 and 1200/mm3 of Blood;
- A rate of 500/MM3 allows to maintain good immunity;
- When the rate becomes less than 200/mm3, the risk of developing opportunistic diseases is very high.
Search for other pathologies
The balance sheet is supplemented by the search for co-existing pathologies: Hepatitis A, hepatitis B, hepatitis C, sexually transmitted infections, opportunistic infections…
A review of the functioning of the main organs: liver, kidneys… is done before the treatment is started.