Since the tuberculosis epidemic in the beginning of the 19th century, there has not been as much preoccupation linked to the appearance of a new virus as for the appearance of AIDS.

The human immunodeficiency virus (HIV) is at the origin of the syndrome and destroys a specific type of white blood cells. The process leads to the reduction of natural resistance in a patient. Bacteria and microbes that do not cause any harm to a normal healthy adult will harm a person infected with the HIV virus.

A considerable difference has to be made between people who are HIV carriers and people who present AIDS symptoms. All patients affected by AIDS are HIV positive but not all HIV positive patients have AIDS. It is only when a patient shows symptoms of the disease that you can talk about AIDS. HIV positive persons do not necessarily present symptoms but they can transmit the virus to other persons.

The virus incubation period is defined as the interval between the current infection and the development of the first AIDS symptoms. Most of the people develop AIDS only a few years later after having been contaminated by the HIV virus.

Despite the discovery of antiretroviral medication and despite the progress accomplished to enlarge access to HIV treatment, AIDS epidemic continues to make progress. No region of the world is spared. 

AIDS origins

We know little about the exact origins of AIDS and hypotheses are numerous. It is suspected that the virus developed in Africa. It is nearly certain that transmission took place between animal and human. But the virus primary reservoir stays virtually unknown. A chimpanzee population would be the diffusion vector of the AIDS virus. But nothing indicates for sure that it is the disease primary reservoir. A study on apes of Africa showed that they adapted to the virus and that they did not develop the disease. A lot of researchers would like to know the HIV natural reservoir in order to be able to analyse the immunological and genetic resistance factors in order to conceive a new vaccine or new treatments.

Transmission modes

Even if the HIV virus has been detected in blood, sperm, saliva, tears, maternal milk and vaginal secretions, sexual transmission stays the major transmission mode. Oral transmission is possible, particularly by genitor-oral contact in the presence of skin lesions and wounds. The virus can also be transmitted from mother to child by placenta, blood transfusion, organ transplants or via infected syringe needles.

Activities with risks

• Homosexual contacts
• Consumption of drugs by intravenous (sharing of syringes)
• Prostitution (in relation to drugs usage by intravenous consumed by that type of group)
• Blood transfusion and transfusion of blood derived products
• Anal sexuality
• Unknown or multiple sexual partners (promiscuity without protection)

AIDS symptoms

AIDS symptoms can be very varied.

Glands swelling, loss of weight, fever, cold, headache, excessive sudation, night sweat, unexplained tiredness, laboured cough, spasmodic and short breathing, skin and mouth lesions, swollen gums, chronic diarrhoea, loss of voice, loss of memory, flu, persistent sore throat can occur. Symptoms vary according to the type of opportunist infection.

Treatment

• Antiretroviral medication is used in order to slow down progression of the disease.
• An individual treatment is prescribed to patients who develop bacterial and mycotic infections.

Prevention of viral transmission remains an essential factor in the control of that epidemic.

Seroconversion

In most cases a patient develops HIV antibodies from 3 to 6 months after exposure to the virus. We then say that the person in question is HIV positive.

The development of HIV virus or seroconversion can be accompanied by fever, malaise and lymphatic ganglions swelling. The symptoms can frequently look like the ones of a common flu and disappear but infection by the HIV virus subsists.

It is extremely important to know that a group can transmit the HIV virus before its HIV positiveness is demonstrated by a test.

Opportunist infections

Patients affected by AIDS suffer of bacteriological and viral secondary infections, of skin and mucous membranes mycoses, of tuberculosis, toxoplasmosis, and of cytomegalovirus infections.

Some forms of cancer (Kaposi’s Sarcoma) also appear more commonly in patients affected by AIDS.

HIV virus in Belgium

Breakdown by sex and by infection modes (situation on the 31 December 2004)

The number of HIV infections recently diagnosed since 1997 in Belgium significantly increased. But the number of AIDS newly diagnosed cases has dropped by half between 1995 and 1997 notably thanks to the more effective antiretroviral treatments. A status quo is observed from the year 1997.

The HIV virus in Europe 

Reporting of AIDS cases and of HIV infection diagnoses by country and by transmission group of adults/teenagers cases (%) (31/12/03)

Prevention advices

• Use of latex condoms is an absolute recommendation in order to reduce the risk, except between monogamous partners who both present a negative result to the virus test.
• Do not share personal utensils (razor, toothbrush, …) that can lead to viral inoculation via a wound or a scratch on the skin.
• Avoid occasional and multiple sexual partners, sexual intercourses with persons with a sexual context unknown to you or belonging to groups presenting risks.
• Do not share objects of sexual insertion that can transmit the virus.
• Avoid oral-anal contact, oral-genital sexuality (particularly in the presence of oral or genital ulcers) and anal penetration. As a general rule, avoid any contact with blood, sperm, urine or excrements.
• Health workers have to avoid any contact with potentially infected material (blood, urine, sperm or excrements) by always using gloves (and a mask) during medical interventions.

Prevention examples can be as numerous as possible scenarios of contamination, so as a general rule, it is wise to apply any sensible measure that allows avoiding direct physical contact with any potential source of infection.