Definition
The presence of HIV infection does not mean that a person has AIDS. AIDS occurs when the HIV infection has severely damaged the immune system, a process that may take years. The Centers for Disease Control and Prevention (CDC) uses a public health reporting definition for AIDS that has changed several times since 1984 as more is known about the infection. The most recent definition includes a positive HIV blood test along with either a major opportunistic condition or a CD4 count less than 200/mm3. (A normal CD4 count is 800 to 1,200 cells per cubic millimeter of blood – written mm3.) The opportunistic conditions include the following types of cancer, infections, and syndromes that are often linked to AIDS.
Cancers:
* Cervical cancer (invasive)
* Kaposi sarcoma
* Burkitt's lymphoma, immunoblastic lymphoma, or brain lymphoma
* (for more information, see section on AIDS-Related Cancers).
Infections:
* Coccidioidomycosis
* Cryptococcosis
* Cryptosporidiosis (chronic intestinal, greater than 1 month duration)
* Cytomegalovirus disease (other than liver, spleen, or nodes)
* Cytomegalovirus retinitis (with loss of vision)
* Herpes simplex (chronic ulcer[s] or bronchitis, pneumonitis, or esophagitis)
* Histoplasmosis
* Isosporiasis (chronic intestinal)
* Mycobacterium avium complex or M. kansasii
* Mycobacterium, tuberculosis (any site)
* Pneumocystis carinii pneumonia
* Pneumonia (recurrent)
* Salmonella septicemia (recurrent)
* Toxoplasmosis of the brain
* Candidiasis of bronchi, trachea, lungs, or esophagus
(For further information on infection, see our document, "Infections in People with Cancer.")
Syndromes:
* Encephalopathy (HIV-related; AIDS dementia)
* Progressive multifocal leukoencephalopathy
* HIV wasting syndrome
This definition has been used for finding and reporting AIDS in the United States. It is less helpful these days because most patients are treated before these problems can happen. The number of HIV-infected people has become more important than the number with AIDS.
Most doctors use the CD4 or T cell count and the amount of HIV in the blood to make decisions about how to treat people with this infection. When possible, most doctors prefer to start treatment of HIV infection before it has progressed to an opportunistic illness or AIDS.