What is HIV?

The Human Immunodeficiency Virus (HIV) is a retrovirus that can lead to Acquired Immune Deficiency Syndrome (AIDS). HIV attacks those cells of the immune system that protect the body. The virus uses these cells to reproduce.

From infection to AIDS: After infection, HIV spreads throughout the body. The cells most severely affected by HIV are called T helper lymphocytes (CD4+ cells), but it can also affect other cells and stay in a dormant phase. CD4+ cells play a crucial role in the maintenance of the human immune system. After infection, HIV uses CD4+ cells as hosts to make copies and infect other cells. This process leads to a vast reduction of CD4+ cells causing the immune system to fail over time. The time taken for disease progression from infection to AIDS varies greatly from person to person.

The stage shortly after infection: Primary HIV infection - is marked by an extensive replication of the virus. The infected person develops usually mild symptoms, so-called "flu-like" symptoms but without cough or a running nose. Some people show a non-itching rash (small red spots all over the body). Even though the person is highly infectious, HIV antibody tests will not likely be positive yet, as the immune system needs some time to build antibodies.

The second stage: This is called the clinically asymptomatic stage. This phase can last up to 10 years, but could be as short as a few months. No major symptoms occur and a strong immune defence keeps the level of HIV low. Antibodies are now detectable in the blood and so HIV antibody tests will show a positive result. The person is still infectious.

Symptomatic HIV infection: Over time the immune system weakens further as the CD4-cell count drops. During the 'symptomatic' stage a person begins to develop frequent, mostly mild illnesses. The more the immune system fails, the less CD4+ cells are present. More symptoms develop. Serious opportunistic infections develop.

The progression from HIV to AIDS is marked by a rapid decline of CD4+ cells. The CD4+ cell count usually falls below 200 at this stage, and opportunistic infections occur more frequently.

Slowing down the virus: Although there is no cure for HIV, there are drugs that suppress the reproduction of the virus dramatically and therefore help the immune system. There are other drugs available to help treat and prevent opportunistic infections.