AIDS-Related Opportunistic Infections--mortality Black or African American Bacteremia--mortality Bisexuality CD4 Lymphocyte Count Cytomegalovirus Infections--mortality Female HIV Infections--transmission Homosexuality, Male Humans Lymphoma--mortality Male Mycobacterium avium-intracellulare Infection--mortality Pneumonia, Bacterial--mortality Risk Factors Sarcoma, Kaposi Sex Factors Sexual Partners Substance Abuse, Intravenous Survival Analysis Toxoplasmosis--mortality White People