Three-year virological outcomes among adolescent girls and young women living with human immunodeficiency virus enrolled in vertical transmission prevention services during pregnancy and postpartum in Tanzania: A prospective cohort study.

OBJECTIVES

This large cohort study examines long-term trends and predictors of viremia among pregnant and postpartum adolescent girls and young women (AGYW) living with human immunodeficiency virus (HIV) in Tanzania.

METHODS

This prospective cohort study included 7703 pregnant/postpartum AGYW with at least one viral load (VL) enrolled in routine prevention of mother-to-child transmission (PMTCT) care between 2018 and 2020 across three regions in Tanzania and followed for a minimum of 36 months. Poisson generalized linear models with a log link function were used to estimate adjusted incidence rate ratios and 95% confidence intervals for detectable viremia (VL ≥50 copies/mL) by baseline exposures.

RESULTS

Over three years, detectable viremia was highest among the youngest age group 15-17 years (20.4%) compared with those aged 18-19 (16.7%) and 20-24 years (12.5%). Viremia declined during pregnancy but plateaued postpartum, with >10% of participants remaining viremic. Perinatally infected AGYW (HIV diagnosis at age ≤12 years) had higher rates of viremia (28.8%) than those already receiving antiretroviral therapy (ART) (11.0%) or newly initiated on ART (15.2%) who were diagnosed after childhood. Over 25% of perinatally infected AGYW remained viremic throughout the PMTCT cycle. Second-line ART and urban residence were associated with higher risk of viremia.

CONCLUSION

Persistently high viremia was observed over time among Tanzanian pregnant/postpartum AGYW with HIV, particularly adolescents and those with perinatally acquired infection. Tailored PMTCT interventions, including resistance-informed treatment and youth-friendly adherence support, are needed to improve maternal outcomes and accelerate elimination of vertical transmission.