title: National prevalence and trends of HIV transmitted drug resistance in Mexico.
abstract: BACKGROUND
  Transmitted drug resistance (TDR) remains an important concern for the management of HIV infection, especially in countries that have recently scaled-up antiretroviral treatment (ART) access.
  
  
  RESULTS
  We designed a study to assess HIV diversity and transmitted drug resistance (TDR) prevalence and trends in Mexico. 1655 ART-naïve patients from 12 Mexican states were enrolled from 2005 to 2010. TDR was assessed from plasma HIV pol sequences using Stanford scores and the WHO TDR surveillance mutation list. TDR prevalence fluctuations over back-projected dates of infection were tested. HIV subtype B was highly prevalent in Mexico (99.9%). TDR prevalence (Stanford score>15) in the country for the study period was 7.4% (95% CI, 6.2∶8.8) and 6.8% (95% CI, 5.7∶8.2) based on the WHO TDR surveillance mutation list. NRTI TDR was the highest (4.2%), followed by NNRTI (2.5%) and PI (1.7%) TDR. Increasing trends for NNRTI (p = 0.0456) and PI (p = 0.0061) major TDR mutations were observed at the national level. Clustering of viruses containing minor TDR mutations was observed with some apparent transmission pairs and geographical effects.
  
  
  CONCLUSIONS
  TDR prevalence in Mexico remains at the intermediate level and is slightly lower than that observed in industrialized countries. Whether regional variations in TDR trends are associated with differences in antiretroviral drug usage/ART efficacy or with local features of viral evolution remains to be further addressed.
authors: Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico.
authors: Santiago
authors: S
authors: Avila-Ríos
authors: Claudia
authors: C
authors: García-Morales
authors: Daniela
authors: D
authors: Garrido-Rodríguez
authors: Christopher E
authors: CE
authors: Ormsby
authors: Ramón
authors: R
authors: Hernández-Juan
authors: Jaime
authors: J
authors: Andrade-Villanueva
authors: Luz A
authors: LA
authors: González-Hernández
authors: Indiana
authors: I
authors: Torres-Escobar
authors: Samuel
authors: S
authors: Navarro-Álvarez
authors: Gustavo
authors: G
authors: Reyes-Terán
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology; D015331:Cohort Studies; D012321:DNA-Directed RNA Polymerases / Q000097:blood; D024882:Drug Resistance, Viral / Q000235:genetics; D058872:Epidemics / Q000706:statistics & numerical data; D005260:Female; D014644:Genetic Variation; D015658:HIV Infections / Q000097:blood / Q000635:transmission*; D015497:HIV-1 / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D010802:Phylogeny; D015995:Prevalence
chemical_list: D019380:Anti-HIV Agents; D012321:DNA-Directed RNA Polymerases