Impact of HIV-1 primary drug resistance on the efficacy of a first-line antiretroviral regimen in the blood of newly diagnosed individuals in Bamako, Mali

Background: To achieve the 90-90-90 targets assigned by UNAIDS, it is crucial to monitor ART in HIV-1-infected patients, especially in resource-limited countries. Objectives: To evaluate the immunovirological response after 12 months of ART in newly HIV-1-diagnosed people in Bamako, Mali; to determine primary and acquired resistance rates to antiretroviral drugs; and to evaluate the impact of primary resistance on the efficacy of ART. Patients and methods: One hundred and nineteen HIV-1-infected people (88.2% women; median age 34 years) were enrolled between January and June 2014. HIV-1 RNA loads (Abbott RealTime HIV-1 assay) were tested in the blood before and at months 3, 6 and 12 after initiation of ART. Primary and acquired resistances to ART were evaluated by the Viroseq (TM) HIV-1 genotyping assay. Results: During the study, 8.4% of people died and 37% were lost to follow-up. After 1 year of ART, an undetectable HIV-1 RNA viral load was found in 87.7% of cases. The overall rate of primary drug resistance mutations was 17.5% (3.2%, 15.9% and 0% for NRTIs, NNRTIs and PIs, respectively). These mutations were not associated with either higher mortality rates or larger numbers of virological failures. The acquired resistance rate was estimated at 3.1%. Conclusions: Our study showed a high primary resistance level and a huge proportion of people non-adherent to the treatment programme. Reassuringly, almost 90% virological success and a low level of acquired mutations were observed in adherent people at month 12. Reinforced education, regular virological monitoring and early HIV-1 diagnosis may help to improve retention in the care system.