HIV SeropositivityHIV SeroprevalenceHIV InfectionsSubstance Abuse, IntravenousSexual BehaviorAntiretroviral Therapy, Highly ActiveRisk FactorsDisease ProgressionSeroepidemiologic StudiesAnti-HIV AgentsCD4 Lymphocyte CountHIV-1Viral LoadAcquired Immunodeficiency SyndromeAntibodies, ViralAntibodies, BacterialChlamydophila pneumoniaeImmunoglobulin GHIV SeronegativityChlamydophila InfectionsAIDS-Related Opportunistic InfectionsEnzyme-Linked Immunosorbent AssayPrevalenceSerologic TestsCohort StudiesHIV Protease InhibitorsHelicobacter pyloriHelicobacter InfectionsCross-Sectional StudiesProspective StudiesCytomegalovirus InfectionsHepatitis CTime FactorsToxocariasisCase-Control StudiesAntibodies, ProtozoanToxoplasmosisAnti-Retroviral AgentsTreatment OutcomeHIVFollow-Up StudiesRNA, ViralPapillomavirus InfectionsBrazilHerpesvirus 2, HumanToxocaraCytomegalovirusRetrospective StudiesAge FactorsAIDS SerodiagnosisCD4-Positive T-LymphocytesIncidenceBlood DonorsCytomegalovirus RetinitisNeosporaMultivariate AnalysisToxoplasmaHomosexuality, MaleOdds RatioRural PopulationHIV AntigensReverse Transcriptase InhibitorsCell CycleHerpes GenitalisSyphilisImmunoglobulin AMolecular Sequence DataHepatitis BSarcoma, KaposiHuman papillomavirus 16UgandaHomosexualityLymphoma, AIDS-RelatedRisk-TakingHIV-Associated Lipodystrophy SyndromeLogistic ModelsImmunoglobulin MPregnancy Complications, Infectious