Clinical Definition

HIV, or human immunodeficiency virus, is a retrovirus that destroys the vital CD4 + T-cells of the immune system. Destruction of CD4 cells decreases immune system function and leaves patients susceptible to infections and disease. The infection can progress into acquired immunodeficiency syndrome (AIDS) if CD4+ T cells decrease to less than 200 cells per cubic millimeter of blood, or if an opportunistic infection like pneumocystis pneumonia is present.

In Our Own Words

Although HIV and AIDS may be used interchangeably, they are not the same thing. HIV is an infection of the humanimmunodeficiency virus. The virus is transmitted through contact with bodily fluids, such as vaginal and anal secretions, semen and blood. As a result of long-term infection, acquired immunodeficiency syndrome (AIDS) can develop.

The AIDS virus attacks the white blood cells in the immune system, which help battle disease. As the virus infects the cells, the immune system functions improperly and the body may be unable to fight off invading infections. When the number of white blood cells, referred to as “T cells” decreases to a certain level, or when complication of the HIV virus develop, a doctor will make the diagnosis of AIDS.