The Human Immunodeficiency Virus (HIV) is a virus that attacks the body's immune system. A healthy immune system provides a natural defence against disease and infection.
HIV infects special cells, called CD4 cells, that are found in the blood and are responsible for fighting infection. After becoming infected, the CD4 cells are destroyed by HIV. Although the body will attempt to produce more CD4 cells, their numbers will eventually decline and the immune system will stop working. This leaves a person who is infected with HIV with a high risk of developing a serious infection or disease, such as cancer.
How is HIV spread?
HIV is spread through the exchange of bodily fluids. This most commonly happens during sexual intercourse, including oral and anal sex. HIV can also be transmitted through sharing needles, or from a pregnant woman to her unborn baby.
There is no cure for HIV and no vaccine to stop you from becoming infected. However, since the 1990s, treatments have been developed that enable most people with HIV to stay well and live relatively normal lives.
What is a retrovirus?
HIV is a special type of virus known as a retrovirus. Retroviruses spread by breaking down the DNA in our cells and then reassembling it to make copies of themselves. Retroviruses are challenging to treat as they can rapidly mutate (alter) into new strains of virus.
What is AIDS?
Acquired Immune Deficiency Syndrome (AIDS) is a term that is used to describe the latter stages of HIV, when the immune system has stopped working and the person develops a life-threatening condition, such as pneumonia (infection of the lungs).
The term AIDS was first used by doctors when the exact nature of the HIV virus was not fully understood. However, the term is no longer widely used because it is too general to describe the many different conditions that can affect somebody with HIV. Specialists now prefer to use the terms advanced or late-stage HIV infection.
