Evolution of transmitted HIV-1 drug resistance in HIV-1 infected patients in Italy from 2000 to 2010.

Prevalence and predictors of transmitted drug resistance (TDR), defined as the presence of at least one WHO surveillance drug resistance mutation (SDRM), were investigated in antiretroviral-naive HIV-1-infected patients, with a genotypic resistance test (GRT) performed <6 months before starting cART between 2000 and 2010. 3163 HIV-1 sequences were selected (69% subtypeB). Overall, the prevalence of TDR was 12% (13.2% subtype B, 9% non-B). TDR significantly declined overall and for the single drug classes. Older age independently predicted increased odds of TDR, whereas a more recent GRT, a higher HIV-RNA and C vs B subtype predicted lower odds of TDR.