AIDS

AIDS (acquired immune deficiency syndrome) (aydz) n. a syndrome caused by the human immunodeficiency virus (HIV), which destroys a subgroup of lymphocytes, resulting in suppression of the body's immune response (see (helper) T-cell). AIDS is essentially a sexually transmitted disease, either homosexually or heterosexually, but it can also be spread via infected blood or blood products and from an infected mother to her child in the uterus, during parturition, or in breast milk. Acute infection following exposure to the virus results in the production of antibodies (seroconversion), but not all those who seroconvert progress to chronic infection. The chronic stage may include persistent generalized involvement of the lymph nodes; AIDS-related complex (ARC), including intermittent fever, weight loss, diarrhoea, fatigue, and night sweats; and AIDS itself, presenting as opportunistic infections (especially pneumonia caused by Pneumocystis jiroveci) and/or tumours, such as Kaposi's sarcoma.

Ordinary social contact with HIV-positive subjects involves no risk of infection. However, high standards of clinical practice are required by all health workers in order to avoid inadvertent infection via blood, blood products, or body fluids from HIV-positive people. Staff who become HIV-positive are expected to declare their status and will be counselled.