Prevalence of low-level viremia and its association with virological failure among adolescents living with HIV in Eastern Cape, South Africa.

OBJECTIVES

Low-level viremia (LLV) has been associated with an increased risk of virological failure among adults on antiretroviral therapy (ART). However, evidence on the clinical implications of LLV among adolescents living with HIV remains limited. This study aimed to assess the prevalence and predictors of LLV and to determine the association between LLV and subsequent virological failure.

METHODS

We analysed data from an integrated prospective cohort of adolescents living with HIV linked to the National Institute for Communicable Diseases (NICD) data warehouse in South Africa. Using routine viral load data from 2015 to 2021, we estimated the prevalence of LLV at the first test. We then used mixed-effects logistic regression to identify socio-demographic factors associated with LLV. Among adolescents with at least three viral load measurements, we assessed the association between LLV and subsequent virological failure using a Cox proportional hazards model in RStudio.

RESULTS

Among 730 adolescents, the prevalence of LLV ranged between 10.4% and 20.1%. Older adolescents aged 15-19 years (aOR: 1.92; 95% CI: 1.44-2.55) and those ≥20 years (aOR: 1.69; 95% CI: 1.12-2.57) had significantly higher odds of LLV compared to those 10-14 years. Among 617 adolescents, 13.3% had LLV, of which 17.1% subsequently progressed to virological failure. Those experiencing LLV were associated with a four-fold (aHR 4.91; 95% CI: 2.46-9.79) increased hazard of virological failure compared to suppressed adolescents.

CONCLUSIONS

The prevalence of LLV among adolescents living with HIV on ART is high and LLV strongly predicts virological failure. Enhanced adherence support for adolescents with LLV is needed to minimize the risk of long-term virological failure.