Heterocyclic Compounds, Bridged-RingDrug Resistance, ViralHIV InfectionsAnti-HIV AgentsLost to Follow-UpDrug TherapyAnti-Retroviral AgentsHIVHIV-1NamibiaHIV ProteaseWorld Health OrganizationHIV SeropositivityHIV Reverse TranscriptaseHIV Protease InhibitorsReverse Transcriptase InhibitorsDried Blood Spot TestingViral LoadDrug Resistance, Multiple, ViralGenotyping TechniquesSentinel SurveillanceAntiretroviral Therapy, Highly ActiveCameroonCD4 Lymphocyte CountMutationMedication AdherenceDrug Therapy, CombinationPrevalencePopulation SurveillanceDeveloping CountriesHIV SeroprevalenceGenotypeHIV SeronegativityTreatment FailureTreatment OutcomeAsia, SoutheasternPatient Compliance