HIV SeropositivityHIV SeroprevalenceHIV InfectionsDisease ProgressionAcquired Immunodeficiency SyndromeSubstance Abuse, IntravenousHIV-1Sexual BehaviorRisk FactorsViral LoadSeroepidemiologic StudiesSimian Acquired Immunodeficiency SyndromeSimian immunodeficiency virusnef Gene Products, Human Immunodeficiency VirusAntiretroviral Therapy, Highly ActiveCohort StudiesMacaca mulattaCD4-Positive T-LymphocytesCD4 Lymphocyte CountAnti-HIV AgentsAntibodies, ViralAntibodies, BacterialChlamydophila pneumoniaeImmunoglobulin GChlamydophila InfectionsHIV SeronegativityEnzyme-Linked Immunosorbent AssayPrevalenceSerologic TestsAIDS-Related Opportunistic InfectionsHelicobacter pyloriHelicobacter InfectionsCross-Sectional StudiesProspective StudiesCytomegalovirus InfectionsToxocariasisHepatitis CCase-Control StudiesAntibodies, ProtozoanTime FactorsAIDS SerodiagnosisToxoplasmosisHerpesvirus 2, HumanTreatment OutcomeBrazilPapillomavirus InfectionsFollow-Up StudiesToxocaraHomosexualityRetrospective StudiesAge FactorsBlood DonorsIncidenceHIVCytomegalovirusMultivariate AnalysisRural PopulationHomosexuality, MaleNeosporaSouth AfricaRNA, ViralRisk-TakingOdds RatioHIV AntigensSyphilisHerpes GenitalisUgandaImmunoglobulin ASexual PartnersInfectious Disease Transmission, VerticalToxoplasmaCoinfectionHepatitis BHuman papillomavirus 16Cell CycleIndiaLogistic ModelsPregnancy Complications, InfectiousImmunoglobulin MSarcoma, KaposiAIDS Dementia Complex