title: Prevalence of drug resistance and importance of viral load measurements in Honduran HIV-infected patients failing antiretroviral treatment.
abstract: OBJECTIVE
  The Honduran HIV/AIDS Program began to scale up access to HIV therapy in 2002. Up to May 2008, more than 6000 patients received combination antiretroviral therapy (cART). As HIV drug resistance is the major obstacle for effective treatment, the purpose of this study was to assess the prevalence of antiretroviral drug resistance in Honduran HIV-1-infected individuals.
  
  
  METHODS
  We collected samples from 138 individuals (97 adults and 41 children) on cART with virological, immunological or clinical signs of treatment failure. HIV-1 pol sequences were obtained using an in-house method. Resistance mutations were identified according to the 2007 International AIDS Society (IAS)-USA list and predicted susceptibility to cART was scored using the ANRS algorithm.
  
  
  RESULTS
  Resistance mutations were detected in 112 patients (81%), 74% in adults and 98% in children. Triple-, dual- and single-class drug resistance was documented in 27%, 43% and 11% of the study subjects, respectively. Multiple logistic regression showed that resistance was independently associated with type of treatment failure [virological failure (odds ratio (OR) = 1) vs. immunological failure (OR = 0.11; 95% confidence interval (CI) 0.030-0.43) vs. clinical failure (OR = 0.037; 95% CI 0.0063-0.22)], route of transmission (OR = 42.8; 95% CI 3.73-491), and years on therapy (OR = 1.81; 95% CI 1.11-2.93).
  
  
  CONCLUSIONS
  The prevalence of antiretroviral resistance was high in Honduran HIV-infected patients with signs of treatment failure. A majority of study subjects showed dual- or triple-class resistance to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors and protease inhibitors. Virologically defined treatment failure was a strong predictor of resistance, indicating that viral load testing is needed to correctly identify patients with treatment failure attributable to resistance.
authors.affiliation: Department of Microbiology, National Autonomous University of Honduras, Tegucigalpa, Honduras. wendy.murillo@smi.se
authors.forename: Wendy
authors.initials: W
authors.lastname: Murillo
authors.forename: I L
authors.initials: IL
authors.lastname: de Rivera
authors.forename: L
authors.initials: L
authors.lastname: Parham
authors.forename: E
authors.initials: E
authors.lastname: Jovel
authors.forename: E
authors.initials: E
authors.lastname: Palou
authors.forename: A C
authors.initials: AC
authors.lastname: Karlsson
authors.forename: J
authors.initials: J
authors.lastname: Albert
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D024921:Drug Resistance, Multiple, Viral / Q000235:genetics*; D004359:Drug Therapy, Combination; D005260:Female; D015751:Genes, pol / Q000235:genetics*; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006721:Honduras; D006801:Humans; D008297:Male; D055118:Medication Adherence; D017422:Sequence Analysis, DNA / Q000379:methods; D017211:Treatment Failure; D019562:Viral Load
chemical_list: D044966:Anti-Retroviral Agents