HIV Virologic Failure among Patients with Persistent Low-Level Viremia in Nairobi, Kenya: It Is Time to Review the >1000 Virologic Failure Threshold

Abstract

Persistent low-level viremia (PLLV) of 200-999 copies/ml has been reported as a risk factor for HIV virologic failure (VF). This retrospective study was aimed at characterizing patients with PLLV, determining factors associated with VF, and determining the effect of regimen change. Data were extracted from electronic medical records for HIV care and treatment. Patients’ characteristics ( $N=705$ ) were as follows: a mean age of 42 years, majority female (55%), and 51% married. A majority (78.7%) had a history of opportunistic infections in their ART lifetime. To determine factors associated with VF, 187 records on patients who maintained PLLV and 12 on deceased patients at the time of data review were eliminated from the analysis, leaving 506 patient records. Out of the 506, 89% (451/506) suppressed VL to nondetectable levels while 11% (55/506) had VF, and the difference was significant ( $P=0.0001$ ). Virologic failure was significantly associated with ages 10-30 years ( $P<0.05$ ). Baseline $\text{VL}\ge 1000$ (OR 3.929; $P=0.002$ ) and 200-999 copies/ml (OR 4.062; $P=0.004$ ) were associated with VF. During PLLV, factors associated with VF included the following: PLLV of 200-999 copies/ml ( $P<0.05$ ), viral blips (OR 4.545; $P=0.0001$ ), mean maximum VL ( $P<0.05$ ), and age ( $P=0.043$ ). Married marital status was inversely associated with VF (OR 0.318; $P=0.026$ ). Regimen change was not significantly associated with virologic outcomes. However, patients who switched regimens to the second line had a high risk of VF ( $P=0.028$ ; OR 3.203). Regimen change was significantly high ( $P<0.05$ ) among adolescents and patients with a start regimen of 2NRTI+1NNRTI. Most of the PLLV patients (89%) achieved nondetectable VL after their continued ART monitoring for at least 12 months. Therefore, PLLV was not an indicator of VF. However, a consistent VL of ≥200-999 copies/ml at baseline and more than 12 months of ART care and treatment were significantly associated with VF. Patients with VL 200-999 copies/ml, adolescents, and young adults require intensive ART monitoring and support.