<s>[INST] When does a person have AIDS? [/INST] The term AIDS applies to the most advanced stages of HIV infection.

The majority of people infected with HIV, if not treated, develop signs of AIDS within eight to 10 years.

AIDS is identified on the basis of certain infections. Stage 1 HIV disease is asymptomatic and not categorized as AIDS. Stage II (includes minor mucocutaneous manifestations and recurrent upper respiratory tract infections), III (includes unexplained chronic diarrhoea for longer than a month, severe bacterial infections and pulmonary tuberculosis) or IV (includes toxoplasmosis of the brain, candidiasis of the oesophagus, trachea, bronchi or lungs and Kaposi’s sarcoma) HIV disease are used as indicators of AIDS. Most of these conditions are opportunistic infections that can be treated easily in healthy people.

In addition, the United States Centers for Disease Control and Prevention defines AIDS on the basis of a CD4-positive T-cell count of less than 200 per mm3 of blood (see: http://www.cdc.gov/epo/dphsi/print/aids1993.htm). CD4-positive T-cells are critical in mounting an effective immune response to infections. Source: UNAIDS. Link: https://www.unaids.org/en/frequently-asked-questions-about-hiv-and-aids. Field: Infectious Disease. Disease: HIV </s>