HIV InfectionsHIV SeropositivityHIV SeroprevalenceHIV-1Acquired Immunodeficiency SyndromeHIV SeronegativityAnti-HIV AgentsAIDS SerodiagnosisHIVSexual BehaviorCD4 Lymphocyte CountHomosexuality, MaleRisk-TakingAnti-Retroviral AgentsViral LoadSubstance Abuse, IntravenousAIDS-Related Opportunistic InfectionsPrevalenceSouth AfricaAntiretroviral Therapy, Highly ActiveSexual PartnersHIV AntigensRisk FactorsCD4-Positive T-LymphocytesAIDS Dementia ComplexProstitutionZimbabweHIV Protease InhibitorsCondomsHIV Core Protein p24HomosexualityInfectious Disease Transmission, VerticalUnsafe SexCross-Sectional StudiesUgandaSyphilisPregnancy Complications, InfectiousHeterosexualityHIV AntibodiesHIV Envelope Protein gp120Africa South of the SaharaMalawiCoinfectionCohort StudiesAIDS-Related ComplexUnited StatesHIV Wasting SyndromeCounselingCircumcision, MaleReceptors, HIVSafe SexHealth Knowledge, Attitudes, PracticeVirus ReplicationRNA, ViralReceptors, CCR5Sexually Transmitted DiseasesIncidenceVoluntary ProgramsPregnancyZidovudineEpidemicsHIV-2Population SurveillanceHIV Reverse TranscriptaseHIV Long-Term SurvivorsTuberculosisSubstance-Related DisordersZambiaMass ScreeningTanzaniaHIV EnteropathyNeedle SharingAntigens, CD4Sex WorkersHepatitis CSexually Transmitted Diseases, ViralCD8-Positive T-LymphocytesHIV ProteasePrisonersIndiaKenyaRural PopulationCenters for Disease Control and Prevention (U.S.)RwandaProspective StudiesViremiaDisease ProgressionSocioeconomic FactorsSimian Acquired Immunodeficiency SyndromeDrug Resistance, ViralNew York CityLogistic ModelsAfricaTime FactorsOrganophosphonatesTuberculosis, PulmonaryInfant, NewbornSimian immunodeficiency virusCrack CocaineReverse Transcriptase Inhibitors