Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS)
Infectious agent: Human Immunodeficiency Virus (HIV). There are two types of HIV, HIV-1 and HIV-2. HIV-2 occurs primarily in Africa, and only rarely in the United States; therefore, unless otherwise noted, the term “HIV” primarily refers to HIV-1.
Description of illness: HIV damages a person’s body by destroying specific blood cells, called CD4+ T cells, which are crucial to helping the body fight diseases. People are diagnosed with AIDS when their CD4+ T cell count is below 200 cells/mm. Within a few weeks of being infected with HIV, some people develop flu-like symptoms, but others have no symptoms at all. People living with HIV may appear and feel healthy for several years. However, even if they feel healthy, HIV is still affecting their bodies. All people with HIV should be seen on a regular basis by a health care provider experienced with treating HIV infection. Effective HIV treatment can slow down the destruction of the immune system, improve the health of people living with HIV, and reduce a person’s HIV infectiousness.