title: Transmission of HIV drug resistance: lessons from sensitive screening assays.
abstract: OBJECTIVE
  The review discusses new technologies for the sensitive detection of HIV drug resistance, with a focus on applications in antiretroviral treatment (ART)-naïve populations.
  
  
  RESULTS
  Conventional sequencing is well established for detecting HIV drug resistance in routine care and guides optimal treatment selection in patients starting ART. Access to conventional sequencing is nearly universal in Western countries, but remains limited in Asia, Latin America, and Africa. Technological advances now allow detection of resistance with greatly improved sensitivity compared with conventional sequencing, variably increasing the yield of resistance testing in ART-naïve populations. There is strong cumulative evidence from retrospective studies that sensitive detection of resistant mutants in baseline plasma samples lacking resistance by conventional sequencing more than doubles the risk of virological failure after starting efavirenz-based or nevirapine-based ART.
  
  
  CONCLUSIONS
  Sensitive resistance testing methods are mainly confined to research applications and in this context have provided great insight into the dynamics of drug resistance development, persistence, and transmission. Adoption in care settings is becoming increasingly possible, although important challenges remain. Platforms for diagnostic use must undergo technical improvements to ensure good performance and ease of use, and clinical validation is required to ensure utility.
authors.affiliation: aInstitute of Infection & Global Health, University of Liverpool, UK bHIV Unit & IrsiCaixa AIDS Research Institute, Hospital Universitari Germans Trias i Pujol, Badalona, Spain cDivision of Infectious Diseases, Yale School of Medicine and VA Connecticut Healthcare System, New Haven, Connecticut, USA.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Geretti
authors.forename: Roger
authors.initials: R
authors.lastname: Paredes
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kozal
mesh_terms: D019380:Anti-HIV Agents / Q000378:metabolism*; D023241:Antiretroviral Therapy, Highly Active; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D024882:Drug Resistance, Viral / Q000235:genetics*; D060005:Genotyping Techniques / Q000191:economics; D015658:HIV Infections / Q000188:drug therapy* / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects; D015276:Health Care Rationing / Q000191:economics; D006801:Humans; D008403:Mass Screening / Q000191:economics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000191:economics / Q000379:methods*
chemical_list: D019380:Anti-HIV Agents; D004279:DNA, Viral; D012367:RNA, Viral