Evaluating HIV Viral Rebound Among Persons on Suppressive Antiretroviral Treatment in the Era of “Undetectable Equals Untransmittable (U = U)”

BACKGROUND: Studies have demonstrated that persons with HIV (PWH) maintaining viral suppression do not transmit HIV to HIV-negative partners through condomless sex, leading to the “Undetectable = Untransmittable (U = U)” prevention campaign. However, few studies have examined the durability of suppression in the era of U = U. METHODS: This retrospective cohort study was conducted in Providence, Rhode Island. PWH aged ≥18 years with documented viral suppression (defined as at least 1 viral load [VL] <200 copies/mL and no VL ≥200 copies/mL) in 2015 were included in the baseline cohort. Primary outcomes were viral suppression, viral rebound (at least 1 VL ≥200 copies/mL), or gap in VL monitoring assessed annually from 2016 to 2019. Those with viral rebound were assessed for resuppression within 6 months. Demographic and clinical characteristics associated with viral rebound or gaps in VL monitoring were investigated by bivariate analysis and logistic regression. RESULTS: A total of 1242 patients with viral suppression were included in the baseline cohort. In each follow-up year, 85%–90% maintained viral suppression, 2%–5% experienced viral rebound, and 8%–10% had a gap in VL monitoring. Among those with viral rebound, approximately one-half were suppressed again within 6 months. In the logistic regression models, retention in care was significantly associated with viral suppression, while younger age, black race, high school or equivalent education, non–men who have sex with men, and history of incarceration were significantly associated with viral rebound. CONCLUSIONS: In the U = U era, most patients with viral suppression who are retained in care are likely to maintain viral suppression over time. Some patients require additional support for regular VL monitoring.