HIV drug resistance among patients experiencing antiretroviral therapy failure in Russia, 2019-2021.

Increasing HIV drug resistance is an important public health concern. The current study aimed to assess HIV drug resistance among people who live with HIV (PLWH) experiencing virological failure. Blood samples and epidemiological characteristics were collected in four Siberian regions from PLWH experiencing ART failure. Partial pol gene sequences were obtained for the study individuals. Drug resistance mutations (DRMs) were predicted using the Stanford HIVdb Program. The association of HIV DRM with epidemiological characteristics was estimated using logistic regression analysis. Further analysis was performed for children (0-14 y old) and adults (≥15 y old) separately. In total, 815 (89.4%) patients were included in the final dataset. Overall, 501 (61.5%) patients had DRM detected. NRTI DRM was more common in children, while NRTI+NNRTI DRM was more frequent in adults (P < 0.001). Krasnoyarsk region, male sex and high viral load were positively associated with the presence of DRM in adults, while higher CD4 cell count and PI/INSTI-based ART had a negative association. No association between epidemiological characteristics and DRM was identified in children. The remaining 38.5% of patients with virological failure had no DRM detected; those patients were likely to have insufficient ART adherence. Most (55.5%) patients had HIV CRF63_02A6, followed by sub-subtype A6 (39.2%). This study revealed poor ART adherence as a main factor driving ART failure among PLWH in the Siberian region. DRM was detected in over 60% of PLWH experiencing ART failure. The current results highlight an urgent need for the introduction of special programs focusing on ART adherence improvement.