Correlates of Virologic Failure Among Breastfeeding Postpartum Kenyan Women on Option B+

BACKGROUND

Option B+ is an HIV/AIDS intervention strategy that streamlines antiretroviral therapy (ART) delivery to pregnant and breastfeeding women in order to improve treatment outcomes, but treatment outcomes have yet to be fully described in field settings. Our study examines the distribution of virologic failure in plasma, breast milk, and endocervical secretions among postpartum breastfeeding mothers using ART while on Option B+ in Kenya, and explores sociodemographic characteristics in this population that were associated with virologic failure.

METHODS

We conducted a retrospective analysis on a cohort of HIV-positive, postpartum, breastfeeding women receiving ART while on Option B+, obtained from a parent cohort study in Nairobi, Kenya. The primary outcome of interest was virologic failure in plasma (HIV RNA >1000 copies/mL), in breast milk (>150 copies/mL), and in endocervical secretions (>100 copies/mL) obtained at 6-14 and 18-24 weeks postpartum. Distributions of virologic failure were described and possible correlates of virologic failure were assessed using univariate tests and multivariate logistic regression.

RESULTS

Of the 42 women in our study, the percentage of women with virologic failure at 6-14 weeks postpartum was 21.4% as detected in plasma; in breast milk, 14.3%, and in endocervical secretions, 23.8%. At 18-24 weeks postpartum, the percentages were 21.1%, 7.1%, and 14.3%, respectively. Younger maternal age, intent to breast feed for longer, and greater weeks of gestation at ART start were significantly associated with virologic failure in plasma (p < 0.05 for each). When adjusted for length of time on ART and low CD4+ count at enrollment, the odds of having virologic failure at 6-14 weeks postpartum were 1.25 times higher (95% CI 1.04, 1.51) for each increase in week of gestation at ART initiation. At 18-24 weeks postpartum, these odds were 1.16 times higher (95% CI 1.02, 1.33) for each increase in week of gestation at ART initiation, adjusted for the same variables.

CONCLUSIONS

Option B+ was designed to lead to earlier initiation of ART during pregnancy. Despite months of ART, nearly one-quarter of the women in our cohort did not achieve virologic suppression in the postpartum period. However, we demonstrated that earlier initiation of ART in pregnancy was associated with suppressed viral loads in plasma after the antepartum and intrapartum periods. Studies with larger sample sizes and longer postpartum evaluation periods are needed to understand the impact of Option B+ in extended HIV transmission risk, maternal outcomes and future pregnancies.