Association of low-level viremia with mortality among people living with HIV on antiretroviral therapy in Dehong, Southwest China: A retrospective cohort study

Objectives To investigate the association of low-level viremia (LLV) with mortality among people living with HIV (PLHIV) on antiretroviral therapy (ART) in Dehong, Southwest China. Methods We analysed data collected from a cohort of PLHIV on ART in Dehong. PLHIV were enrolled in this cohort after they started ART, with viral load (VL) tested once a year afterwards. Each VL level was then categorized into one of the four groups: <50, 50-199, 200-999 and >= 1000 copies/ml. VL levels of 50-199 and 200-999 copies/ml were defined as LLV. The VL level for each participant was re-categorized and fitted into an extended Cox regression model as a time-varying covariate to examine the associations of VL level with all-cause and AIDS-related deaths. Results Among the included 7273 of 8762 PLHIV in this study, median age (interquartile range, IQR) was 36 (30-43) years and 59.9% were male. The patients were followed up for a median duration (IQR) of 6.2 (4.3-8.2) years. Compared with VL <50 copies/ml, LLV 200-999 copies/ml (adjusted hazard ratio [aHR] and 95% confidence interval [95% CI]: 1.56 [1.04, 2.32]) were associated with elevated risk of all-cause mortality and LLV50-199 (aHR [95% CI]: 1.00 [0.68, 1.45]) were not. Similarly, only LLV200-999 copies/ml (aHR [95% CI]: 2.37 [1.36, 4.14]) corresponded to higher risk of AIDS-related mortality. Conclusions This study suggests that PLHIV on ART may have elevated death risks even though the viremia is suppressed at a low level. Interventions targeting PLHIV with LLV should be developed to reduce their mortality.