HIV SeronegativityMumpsRubellaSeroepidemiologic StudiesAntibodies, ViralImmunoglobulin GHIV InfectionsHIV SeropositivityHIV SeroprevalenceHIV-1CD4-Positive T-LymphocytesAIDS SerodiagnosisHIV AntigensAcquired Immunodeficiency SyndromeAnti-HIV AgentsHIV Protease InhibitorsLymphocyte ActivationCD4 Lymphocyte CountSexual BehaviorCD8-Positive T-LymphocytesHomosexuality, MaleAnti-Retroviral AgentsRisk-TakingT-Lymphocyte SubsetsHIV Core Protein p24HIV Reverse TranscriptaseSouth AfricaHIV Envelope Protein gp120Mice, Inbred C57BLT-LymphocytesReceptors, HIVHIV ProteaseViral LoadSexual PartnersDendritic CellsSubstance Abuse, IntravenousPrevalenceCells, CulturedMice, Inbred BALB CMice, TransgenicImmunophenotypingHIV Long-Term SurvivorsCondomsAIDS-Related Opportunistic InfectionsFlow CytometryUgandaG0 PhaseAntigens, CD45Unsafe SexCoinfectionZimbabwe