HIV stands for Human Immunodeficiency Virus. HIV is a virus that causes AIDS. HIV infection can be by blood-to-blood contact, from mother to child and sexually through direct bodily fluids (semen and vaginal fluids). A person with HIV in the body is referred to as HIV positive.
HIV is a retro virus meaning it needs cells from a “host” in order to make copies of itself (replication). When HIV enters the body, it uses CD4 cells to make copies of itself or to replicate.
In the body, there are CD4 cells which are a specialized type of white blood cells that are part of the immune system. The CD4 cells initiate the body’s response to invading infections like viruses.
When in the body, HIV attacks the CD4 cells and uses these cells to make copies of its self damaging them in the process. As more copies of HIV are made, the amount of HIV in the blood increases and more and more CD4 cells are destroyed.
As the number of CD4 cells in the body decreases, the body’s immune system (body’s ability to protect its self from infections and diseases) reduces. The fewer the functioning CD4 cells, the weaker the immune system and therefore the more vulnerable a person is to infections and decreases. A person with a very weak immune system can easily suffer from “opportunistic infections” which rarely cause harm in healthy individuals.
The number of CD4 cells per cubic millimeter of blood is called CD4 count. In a healthy adult the CD4 count is (600-1,200). If the CD4 count is less than 200, the immune system is severely weakened and the HIV positive person is at a very high risk of getting “opportunistic infections”.
AIDS is Acquired Immune Deficiency Syndrome. An HIV positive person is said to have AIDS when the CD4 count is less than 200 or when suffering from certain types of opportunistic infections such as Tuberculosis. It is important to know that not all HIV positive people have AIDS.
The time between HIV infection and progressing to AIDS differs for each person and depends on many factors, including a person’s health status, health-related behaviours and access to health care.
While there is no cure for HIV, antiretroviral therapy (ART) which tries to prevent the virus from replication can slow the progression from HIV infection to AIDS.