Prevalence and time trends of surveillance drug resistance mutations in antiretroviral drug-naive patients who were newly diagnosed of HIV-1 infection from January 2004 through December 2012 in 12 hospitals of the Public Health Service of two regions of Spain, Galicia and Basque Country.

<p>Asterisks indicate that the frequency of TDR to NRTIs from 10% in 2004 to 2% in 2012 was statistically significant (p = 0.01).