The Centers for Disease Control and Prevention (CDC) Definition of AIDS

People who develop symptoms of AIDS will get a diagnosis if they fit certain criteria established by the Centers for Disease Control and Prevention (CDC). The CDC is a federal agency in Atlanta, Georgia, which monitors all infectious diseases in the United States. Doctors who diagnose someone with AIDS are required to report the existence of that case (not the person's name or other identifying information, but simply their diagnosis) to the CDC.

The CDC's definition of AIDS has changed several times since the beginning of the AIDS epidemic. The changes have taken place as scientists learned more about the disease and thus were able to include more people with HIV who develop symptoms or immunodeficiency. The current AIDS definition includes the following conditions: HIV positive, AND CD4 (T-cell) count below 200 OR presence of one or more opportunistic infections.

What is HIV Disease?

At this point, if someone is sick due to HIV, but their illness is not included on the "AIDS list," they may simply be considered to have "HIV disease."