HIV SeropositivityHIV SeroprevalenceHIV InfectionsSubstance Abuse, IntravenousAntiretroviral Therapy, Highly ActiveSexual BehaviorRisk FactorsAnti-HIV AgentsAnti-Retroviral AgentsSeroepidemiologic StudiesCD4 Lymphocyte CountMorbidityHIV-1Viral LoadAcquired Immunodeficiency SyndromeHIV Protease InhibitorsDrug Resistance, ViralReverse Transcriptase InhibitorsHIVAIDS-Related Opportunistic InfectionsAntibodies, ViralPrevalenceSouth AfricaCohort StudiesZidovudineInfectious Disease Transmission, VerticalHIV SeronegativityAntibodies, BacterialRNA, ViralNevirapineMedication AdherenceChlamydophila pneumoniaeImmunoglobulin GUgandaCross-Sectional StudiesChlamydophila InfectionsBenzoxazinesTreatment OutcomeSerologic TestsStavudinePregnancy Complications, InfectiousEnzyme-Linked Immunosorbent AssayProspective StudiesDrug Therapy, CombinationRitonavirOrganophosphonatesPatient ComplianceRetrospective StudiesHIV-Associated Lipodystrophy SyndromeHIV Reverse TranscriptaseLamivudineCoinfectionPregnancyTime FactorsLopinavirHepatitis CIncidenceZimbabweHelicobacter pyloriRural PopulationDrug Resistance, Multiple, ViralCD4-Positive T-LymphocytesHelicobacter InfectionsBrazilMalawiAdenineTreatment FailureAIDS Dementia ComplexCytomegalovirus InfectionsViremiaFollow-Up StudiesIndinavirToxocariasisAIDS SerodiagnosisHIV ProteaseInfant, NewbornImmune Reconstitution Inflammatory SyndromeAge FactorsAntibodies, ProtozoanCase-Control StudiesIndiaHerpesvirus 2, HumanLogistic ModelsNelfinavirAfrica South of the SaharaPyrimidinonesToxoplasmosisLost to Follow-UpMultivariate AnalysisHomosexuality, MaleDidanosineBotswanaOdds RatioUnited StatesZambiaToxocaraBlood DonorsRisk-TakingCytomegalovirusPapillomavirus Infections