Comparison of guidelines for HIV viral load monitoring among pregnant and breastfeeding women in sub-Saharan Africa: a simulation study.

BACKGROUND: Intensified viral load (VL) monitoring for pregnant and breastfeeding women has been proposed to help address concerns around antiretroviral therapy (ART) adherence, viraemia and transmission risk, but there have been no systematic evaluations of existing policies.

METHODS: We used an individual Monte Carlo simulation to describe longitudinal ART adherence and VL from conception until two years postpartum. We applied national and international guidelines for VL monitoring to the simulated data. We compared guidelines on the percentage of women receiving VL monitoring and the percentage of women monitored at the time of elevated VL.

RESULTS: Coverage of VL monitoring in pregnancy and breastfeeding varied markedly, with between 14-100% of women monitored antenatally and 38-98% monitored during breastfeeding. Specific recommendations for testing at either a fixed gestation or a short, fixed period after ART initiation achieved >95% testing in pregnancy but this was much lower (14-83%) among guidelines with no special stipulations. By the end of breastfeeding, only a small proportion of simulated episodes of elevated VL > 1000 copies/mL were successfully detected by monitoring (range, 20-50%).

DISCUSSION: While further research is needed to understand optimal VL frequency and timing in this population, these results suggest that current policies yield suboptimal detection of elevated VL in pregnant and breastfeeding women.