title: Declining prevalence of HIV-1 drug resistance in treatment-failing patients: a clinical cohort study.
abstract: OBJECTIVE
  A major barrier to successful viral suppression in HIV type 1 (HIV-1)-infected individuals is the emergence of virus resistant to antiretroviral drugs. We explored the evolution of genotypic drug resistance prevalence in treatment-failing patients from 1999 to 2005 in a clinical cohort.
  
  
  METHODS
  Prevalence of major International AIDS Society-USA HIV-1 drug resistance mutations was measured over calendar years in a population with treatment failure and undergoing resistance testing. Predictors of the presence of resistance mutations were analysed by logistic regression.
  
  
  RESULTS
  Significant reductions of the prevalence of resistance to all three drug classes examined were observed. This was accompanied by a reduction in the proportion of treatment-failing patients. Independent predictors of drug resistance were the earlier calendar year, prior use of suboptimal nucleoside analogue therapy, male sex and higher CD4 levels at testing.
  
  
  CONCLUSIONS
  In a single clinical cohort, we observed a decrease in the prevalence of resistance to all three examined antiretroviral drug classes over time. If this finding is confirmed in multicentre cohorts it may translate into reduced transmission of drug-resistant virus from treated patients.
authors: Institute of Clinical Infectious Diseases, Catholic University, Rome, Italy. simona.digiambenedetto@rm.unicatt.it
authors: Simona
authors: S
authors: Di Giambenedetto
authors: Laura
authors: L
authors: Bracciale
authors: Manuela
authors: M
authors: Colafigli
authors: Manuela
authors: M
authors: Colatigli
authors: Paola
authors: P
authors: Cattani
authors: Carmen
authors: C
authors: Pinnetti
authors: Carmen
authors: C
authors: Pannetti
authors: Alessandro
authors: A
authors: Bacarelli
authors: Mattia
authors: M
authors: Prosperi
authors: Giovanni
authors: G
authors: Fadda
authors: Roberto
authors: R
authors: Cauda
authors: Andrea
authors: A
authors: De Luca
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016017:Odds Ratio; D011159:Population Surveillance; D015995:Prevalence; D012367:RNA, Viral; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral