Global epidemiology of drug resistance after failure of WHO recommended first-line regimens for adult HIV-1 infection: a multicentre retrospective cohort study. Lancet Infectious Diseases
Gregson et al. on behalf of the TenoRes Study Group did a global assessment of drug resistance after virological failure with first-line tenofovir-containing antiretroviral therapy (ART) including 1’926 individuals from 36 countries. They found that levels of tenofovir resistance in individuals with viral failure ranged from 20% in Europe to more than 50% in sub-Saharan Africa. A CD4 cell count of less than 100 cells per μL, treatment with nevirapine rather than efavirenz, and treatment with lamivudine rather than emtricitabine, were consistently associated with a 50% higher odds of tenofovir resistance in those with viral failure.
In conclusion, optimization of treatment programs and effective surveillance for transmission of drug resistance is crucial in low-income and middle-income regions.