A syndrome resulting from the acquired deficiency of cellular immunity caused by the human immunodeficiency virus (HIV). It is characterized by the reduction of the Helper T-lymphocytes in the peripheral blood and the lymph nodes; opportunistic infections (usually pneumocystis carinii pneumonia, cytomegalovirus (CMV) infections, tuberculosis, candida infections, and cryptococcosis); and the development of malignant neoplasms (usually non-Hodgkin's lymphoma and Kaposi's sarcoma). The human immunodeficiency virus is transmitted through sexual contact, sharing of contaminated needles, or transfusion of contaminated blood. Generalized lymphadenopathy, fever, weight loss, and chronic diarrhea are common symptoms of AIDS. The patients usually die either of opportunistic infections or malignant neoplasms. -- 2004