HIV SeropositivityHIV SeroprevalenceHIV InfectionsSubstance Abuse, IntravenousSexual BehaviorRisk FactorsDisease ProgressionSeroepidemiologic StudiesCD4 Lymphocyte CountAntibodies, ViralAntibodies, BacterialLeukocyte CountChlamydophila pneumoniaeImmunoglobulin GChlamydophila InfectionsEnzyme-Linked Immunosorbent AssaySerologic TestsHIV SeronegativityPrevalencePlatelet CountHelicobacter pyloriHelicobacter InfectionsAcquired Immunodeficiency SyndromeHIV-1ToxocariasisCytomegalovirus InfectionsAntibodies, ProtozoanCross-Sectional StudiesCase-Control StudiesCohort StudiesProspective StudiesToxoplasmosisTime FactorsHepatitis CCell CountHerpesvirus 2, HumanToxocaraAIDS SerodiagnosisBlood DonorsViral LoadAnti-HIV AgentsPapillomavirus InfectionsAge FactorsBlood Cell CountNeosporaRural PopulationCytomegalovirusFollow-Up StudiesHerpes GenitalisBrazilImmunoglobulin ASyphilisHomosexualityOdds RatioHuman papillomavirus 16ToxoplasmaCell CycleRetrospective StudiesImmunoglobulin MAIDS-Related Opportunistic InfectionsHomosexuality, MaleMultivariate AnalysisTreatment OutcomeAntibodies, Helminth