HIV SeropositivityZidovudineHIV SeroprevalenceHIV InfectionsSubstance Abuse, IntravenousSexual BehaviorRisk FactorsSeroepidemiologic StudiesAnti-HIV AgentsDidanosineStavudineLamivudineReverse Transcriptase InhibitorsHIV-1Acquired Immunodeficiency SyndromeZalcitabineInfectious Disease Transmission, VerticalNevirapineHIV Reverse TranscriptaseDideoxynucleotidesAntibodies, ViralCD4 Lymphocyte CountDideoxynucleosidesAIDS-Related ComplexPregnancy Complications, InfectiousAntibodies, BacterialDrug Therapy, CombinationChlamydophila pneumoniaeChlamydophila InfectionsImmunoglobulin GHIV Core Protein p24Serologic TestsIndinavirEnzyme-Linked Immunosorbent AssayViral LoadHIV SeronegativityPrevalenceHIV Protease InhibitorsHelicobacter pyloriDrug Resistance, ViralHelicobacter InfectionsRNA, ViralPregnancyToxocariasisBenzoxazinesAnti-Retroviral AgentsAIDS SerodiagnosisAntibodies, ProtozoanHIV AntigensCytomegalovirus InfectionsThymine NucleotidesAntiviral AgentsToxoplasmosisHIVOrganophosphonatesCross-Sectional StudiesToxocaraInfant, NewbornHerpesvirus 2, HumanAIDS-Related Opportunistic InfectionsBlood DonorsCohort StudiesOxazinesHepatitis CDrug InteractionsDrug Resistance, Multiple, ViralNeosporaCase-Control StudiesPapillomavirus InfectionsHomosexuality, MaleAntiretroviral Therapy, Highly ActiveRural PopulationNelfinavirProspective StudiesDrug Resistance, MicrobialSyphilisHerpes GenitalisCytomegalovirusAdenineToxoplasmaImmunoglobulin ABotswanaBrazilHomosexualityAIDS Dementia ComplexUganda