Low-level viremia is associated with HIV drug resistance and treatment failure: evidence from southwest China

The impact of low-level viremia (LLV) on virologic outcomes and drug resistance in Guangxi, a high-burden region of southwest China, remains poorly characterized. Using the Guangxi HIV/AIDS surveillance database, we conducted a retrospective cohort analysis of 102,855 antiretroviral therapy (ART)-treated individuals aged ≥ 15 years. The association between LLV and subsequent virologic non-suppression and virologic failure was assessed longitudinally; drug resistance mutations (DRMs) were characterized cross-sectionally in a subset of 776 LLV cases (viral load 200–999 copies/mL) with successful genotyping. Data from Guangxi’s HIV surveillance system revealed that 10.68% of patients had LLV at baseline (51–199: 7.60%; 200–399: 1.61%; 400–999: 1.47%), with 7.61% exhibiting virologic non-suppression (≥ 1000 copies/mL). Among LLV cases, 23.31% progressed to non-suppression and 17.23% to virologic failure (≥ 2 consecutive viral load ≥ 1000 copies/mL) during follow-up VL monitoring at approximately 24-week intervals. LLV significantly increased the likelihood of non-suppression (adjusted odds ratio [aOR] 1.91, 95% CI: 1.80–2.04) and failure (aOR 2.03, 95% CI: 1.79–2.29) compared to virologically suppressed individuals. Genotypic analysis of 776 LLV cases identified DRMs in 41.24%, predominantly M184I/V (24.87%) and K103S/N (21.13%), with higher resistance in the 800–999 copies/mL range (aOR 3.36). These findings underscore the importance of intensified viral load monitoring and resistance profiling for patients with LLV to enhance ART efficacy in Guangxi.