Prevalence of HIV-1 transmitted drug resistance and viral suppression among recently diagnosed adults in São Paulo, Brazil

Arch Virol. 2019 Mar;164(3):699-706. doi: 10.1007/s00705-018-04122-8. Epub 2018 Dec 20.


HIV-1 transmitted drug resistance (TDR) mutations may reduce the efficacy of antiretroviral therapy (ART), but pre-treatment testing to determine the virus genotype can improve the efficacy of ART. Unfortunately, issues related to cost and logistics of pre-treatment testing limit its use in resource-limited settings. We studied 596 ART-naive individuals who were newly diagnosed from 2014 to 2016 in São Paulo, Brazil, to evaluate TDR and virological outcome after 48 weeks of genotype-guided therapy. One or more TDR (based on the WHO surveillance list) was observed in 10.9% (CI 95%, 8.6-13.6) of the sequences, the most common of which was the K103 N mutation, which confers resistance to first-generation drugs of the non-nucleoside reverse transcriptase inhibitor (NNRTI) antiretroviral drug class. Dual-class (1%, 6/596) and triple-class (0.34%, 2/596) resistance were uncommon. After 48 weeks of treatment with ART, infection was suppressed to below 200 copies/mL in most patients (95%), with full suppression (RNA target not detected) in 65%. The following characteristics at patient enrollment were independently associated with a lack of full suppression: CD4 T cell counts below 500 cells/µL, viremia above 100,000 copies/mL, older age, and TDR to NNRTI. The rates of resistance were intermediate, but genotype-guided therapy resulted in high rates of viral suppression. The observed resistance profile should not be an obstacle to the use of the dolutegravir-based regimen now recommended in Brazil, but genotype testing may be warranted before initiating first-generation NNRTI-based regimens.

MeSH terms

  • Adult
  • Anti-HIV Agents / pharmacology*
  • Brazil / epidemiology
  • CD4-Positive T-Lymphocytes / virology
  • Drug Resistance, Viral*
  • Female
  • Genotype
  • HIV Infections / diagnosis
  • HIV Infections / drug therapy
  • HIV Infections / epidemiology
  • HIV Infections / virology*
  • HIV-1 / drug effects
  • HIV-1 / genetics
  • HIV-1 / isolation & purification
  • HIV-1 / physiology*
  • Humans
  • Male
  • Prevalence
  • Young Adult


  • Anti-HIV Agents