Heterocyclic Compounds, Bridged-RingHIV InfectionsAnti-HIV AgentsAntiretroviral Therapy, Highly ActiveAnti-Retroviral AgentsHIV-1HIV Protease InhibitorsReverse Transcriptase InhibitorsZidovudineDrug Resistance, ViralCD4 Lymphocyte CountViral LoadNelfinavirOrganophosphonatesAdenineHIVAcquired Immunodeficiency SyndromeIndinavirDidanosineRitonavirNevirapineBenzoxazinesHIV Integrase InhibitorsDrug Therapy, CombinationHIV Reverse TranscriptaseDrug InteractionsInfectious Disease Transmission, VerticalLopinavirHIV SeropositivityDideoxyadenosineDideoxynucleosidesLamivudineAntiviral AgentsRNA, ViralProtease InhibitorsTreatment OutcomeSouth AfricaVirus ReplicationAIDS-Related Opportunistic InfectionsMedication AdherenceStavudinePyridinesHIV SeronegativityCohort StudiesUgandaPatient ComplianceHIV-Associated Lipodystrophy SyndromeHIV SeroprevalenceDrug Resistance, Multiple, ViralCD4-Positive T-LymphocytesAIDS Dementia ComplexPregnancy Complications, InfectiousViremiaMalawiTreatment FailureHIV ProteaseImmune Reconstitution Inflammatory SyndromeCoinfectionPyrimidinonesLost to Follow-UpAfrica South of the SaharaBotswanaPrevalenceRisk FactorsZambiaProspective StudiesZimbabweAIDS SerodiagnosisCross-Sectional Studies