Pretreatment HIV-1 Resistance in Argentina: results from the second surveillance study following WHO guidelines (2019).

More than 62.000 individuals are currently on antiretroviral treatment within the public health system in Argentina. In 2019, more than 50% of people on ART received NNRTIs. To assess the prevalence of HIV-1 drug resistance in Argentina using the WHO guidelines. This was a nationwide cross-sectional study enrolling consecutive 18 year-old and older individuals starting ARVs at 19 ARV-dispensing centers. This allowed us to estimate a point prevalence rate of resistance-associated mutations (RAMs) with a CI of 5% (for the total population and for those without antiretroviral exposure). Four-hundred forty-seven individuals were included in the study. The prevalence of mutations associated with resistance was detected in 27.7% (95 CI 25.6-34.9%) of the population. For NNRTI, it was 19.6% (CI 95 16.3-24.5%), for INSTI 6.1% (CI95 6.1-11.9%), for NRTI 3% (CI95 1.9-5.9%) and for PI 1.5% (CI95 0.7-3.6%). Naive individuals had variants of resistance to NRTIs in 16.8% (CI95 12.8-21.4) and 5.7% (CI95 2.9-15.9) to INSTI. For experienced individuals, the prevalence of variants associated with resistance was 30.38% (95 CI 20.8-42.2) for NRTIs and 7.7% (CI 95 2.9-15.9) for INSTI. The second study conducted in Argentina with nationwide representative sampling shows an increase in the frequency of non polymorphic resistance-associated mutations (RAMs) associated with resistance to NNTRI. This study generates the framework of evidence that supports the use of schemes based on high genetic barrier integrase inhibitors such as DTG as the first line of treatment and the need for the use of resistance test prior to prescribing schemes based on non-nucleoside inhibitors of reverse transcriptase. We report for the first time the presence of a natural polymorphism associated with the most prevalent viral recombinant form in Argentina that could have an impact on first-generation integrase inhibitors such as raltegravir.