HIV SeropositivityHIV SeroprevalenceHIV InfectionsSubstance Abuse, IntravenousSexual BehaviorSeroepidemiologic StudiesRisk FactorsDisease ProgressionAntibodies, ViralAntibodies, BacterialHIV SeronegativityImmunoglobulin GEnzyme-Linked Immunosorbent AssaySerologic TestsChlamydophila pneumoniaeChlamydophila InfectionsPrevalenceCytomegalovirus InfectionsAcquired Immunodeficiency SyndromeHIV-1Herpesvirus 2, HumanAntibodies, ProtozoanHelicobacter pyloriToxocariasisHelicobacter InfectionsCytomegalovirusHerpes GenitalisBlood DonorsNeosporaToxoplasmosisHomosexualityCross-Sectional StudiesCase-Control StudiesCohort StudiesHepatitis CToxocaraCD4 Lymphocyte CountToxoplasmaAIDS SerodiagnosisProspective StudiesImmunoglobulin MBrazilPapillomavirus InfectionsPolymerase Chain ReactionTime FactorsImmunoglobulin AAge FactorsAntibodies, HelminthDog DiseasesAIDS-Related Opportunistic InfectionsSyphilisRural PopulationHomosexuality, MaleViral LoadHerpesviridae InfectionsHIV AntigensHepatitis AHuman papillomavirus 16DNA, ViralHepatitis BFollow-Up StudiesCoccidiosisHepatitis A Virus, HumanRheumatoid FactorZoonosesIncidencePregnancy Complications, InfectiousOdds RatioPregnancyToxocara canisSexual PartnersArthritis, RheumatoidRetrospective StudiesAnti-HIV AgentsQ FeverAntigens, BacterialHerpesvirus 8, HumanChlamydia InfectionsProstitutionIndiaRisk-TakingHepatitis C AntibodiesLogistic ModelsCysticercosisCell CycleMultivariate Analysis