HIV/AIDS Progression
2.1 Overview
To understand the treatment of HIV/AIDS it is important to understand how an HIV infection develops into AIDS. The treatment of HIV/AIDS and its related illnesses is largely informed by the stage at which the HIV infection is at.
2.2 HIV Progression
Caption text. Graph showing HIV copies and CD4 counts over course of a typical HIV infection. As the virus replicates itself, as indicated by the red line, the number of T-helper cells in a person's blood decreases, as indicated by the blue line.Credit: Wikipedia. Copyright: From Wikipedia. (GNU) Free Document License.
After infection, the HI virus enters the blood and attacks the body's immune system, specifically the important T-helper cell which co-ordinates the immune system's response to infections. The HI virus gains entry to the T-helper cell by attaching itself to the CD4 protein on the surface of the cell. Once the HIV has gained entry, it takes over the cell and replicates, seeking new T-helper cells to infect. The infected cell dies after a couple of days.
The body's natural response to an infection is to fight infected cells and replace the cells that have been lost. But gradually the HIV overwhelms the immune system, leaving the body vulnerable to infections and other diseases. The time it takes to do this varies from person to person, but averages at about nine years.
The normal range for CD4+T cells in a healthy person is 800-1200 cells per cubic millilitre of blood. When an HIV infected person's CD4+ T cell count falls below 200, he or she becomes increasingly vulnerable to opportunistic infections. In a person with a healthy immune system these infections would not normally be life-threatening but to an HIV-infected person they could be fatal. Without treatment, the viral load, which refers to the relative amount of free virus in the blood, will increase to the point where the body can no longer fight it.
The progression of the virus can be measured by a CD4 test that measures the amount of CD4 or T-helper cells in your blood. The strength of your immune system is a good predictor of how you will fight infections. The Viral Load test measures the amount of HIV in the blood in every millilitre of blood. A high viral load indicates that the patient is either in the first stage of infection or nearing AIDS.
HIV progression can be divided into 4 stages:
| Stage | Description | Symptoms/Illnesses | Treatment |
| 1. Primary HIV infection | During this stage most individuals will not be aware they are infected, and may even test HIV-negative because their body hasn't reacted to the virus and created antibodies. Symptoms normally occur within three months of infection and generally subside within two weeks. | A flu-like illness, swollen lymph nodes, diarrhoea, fever and fatigue. | Treat the infections and symptoms |
| 2. Asymptomatic stage | No symptoms manifest but the virus remains active. | ||
| 3. Symptomatic stage | Individual begins to feel unwell and experiences infections caused by bacteria and viruses that surround us all daily | Thrush, Herpes Zoster (shingles), Herpes Simplex, Oral Hairy Leukoplakia, Idiopathic Thrombocytopenic Purpura, Pneumococcal Pneumonia. | Prevent/treat opportunistic infections |
| 4. Acquired Immune Deficiency Syndrome (AIDS) | Individual's CD4 count is less than 200. | Pneumocystis carinii Pneumonia (PCP), Kaposi's Sarcoma, Tuberculosis, HIV-Related Lymphoma, (more...) |
Initiate antiretroviral treatment |
