Association Between Dynamic Viral Rebound and Longitudinal Measures of Viral Load/CD4 Counts Among People with HIV in South Carolina.

Monitoring HIV viral rebound (VR) is crucial, as it indicates an increased risk of infection, transmission, disease progression, and drug resistance. This study aims to identify the association between dynamic VR and historical viral load (VL)/CD4 count measures. A 15-year South Carolina population-based electronic health record data were used for the study. VR was defined as the return of detectable levels of VL (>200 copies/mL) after stable viral suppression (VS) (two consecutive VS, i.e., VL ≤200 copies/mL). A generalized linear mixed model was used to evaluate the association between dynamic VR and historical time-dependent predictors, such as nadir CD4 count and comorbidities, within a year prior to each VR. Subgroup analysis for men who have sex with men (MSM) was also conducted. Among 8,185 people with HIV (PWH), 1,173 (14.3%) had a history of VR. Lower nadir CD4 count (≥500 vs. <200 cells/μL; adjusted odds ratio [aOR]: 0.51, 95% confidence interval [CI]: [0.43, 0.60]), younger age (>60 years old vs. 18-30 years old; aOR: 0.43, 95% CI: [0.29, 0.63]), and being Black (Black vs. White; aOR: 1.58, 95% CI: [1.34, 1.85]) were associated with a higher risk of VR, while MSM (MSM vs. heterosexual; aOR: 0.81, 95% CI: [0.67, 0.96]) were associated with decreased VR risk. The rate of VR among PWH in South Carolina is significant. Within-1-year VL/CD4 test is critical for identifying PWH at risk for VR. Tailored interventions are needed for PWH at risk for VR to achieve sustained suppression and better health outcomes.