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

Abstract

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.

Keywords: monitoring; prevention; rebound; suppression; undetectable.

Figure 1.

Study population diagram, with viral suppression defined as <200 copies/mL, including the proportion of participants each year who maintained viral suppression, experienced viral rebound, or did not have viral load data at our center. Abbreviation: PVL, plasma viral load.

Figure 2.

A year-by-year breakdown of the study cohort, with viral suppression defined as (A) <200 copies/mL and (B) <20 copies/mL. Percentages represent proportions of the 2015 baseline cohort who had viral suppression, viral rebound, or no viral load data. Abbreviation: PVL, plasma viral load.