Abstract
Background: PROMISE-EPI trial evaluated a combination of interventions to prevent HIV transmission during breastfeeding. It showed a reduced postnatal transmission compared to the standard of care. The intervention combined identification of infants at high risk of infection using a point of care assay (POC) for early infant diagnosis and monitoring maternal viral load (VL) at 6 weeks and 6 months. A single-drug post-natal prophylaxis (PNP) was immediately initiated for high risk infants (maternal VL ≥ 1000 cp/mL). In Zambia, the national guidelines standard of care differs by 1) using three-drug PNP; 2) quarterly monitoring of maternal VL; 3) maternal VL testing in central labs. We explored the facilitators and barriers of this innovative prevention package to guide future scale-up. Methods: Qualitative methods were used to gather information on PROMISE-EPI trial delivery, context, and behaviors. PROMISE-EPI intervention and control participants, staff members and health care professionals were interviewed. Verbatim transcripts were coded using a priori and emerging codes. Analysis was conducted using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) framework. The determinants were categorized into the 5 domains of the Consolidated Framework for Implementation Research (CFIR) to better identify the causes of intervention success or failure among the 5 RE-AIM components. Results: A total of 37 individual interviews and 15 focus group discussions were conducted. Facilitators included the importance of the connection between the key elements of the intervention (POC and PNP) for immediate clinical action. Rapid maternal VL results induce several positive downstream behaviors in mothers and healthcare professionals, including increased trust in health care system. These can be quickly reversed when point of care testing is sub-optimal, as during the COVID-19 pandemic. Furthermore, the secondary elements of the intervention beyond POC and PNP; namely a warm welcome, a dedicated space, detailed and dedicated counselling, reimbursement for transport, solar panels and batteries, reminders and additional staff; were identified as facilitating its acceptability and fidelity. Conclusion: This study provides new elements to better understand the reduced HIV transmission with the PROMISE-EPI intervention. It also highlights potential gaps between the package proposed in the trial and what can be applied in less controlled, ‘real life’ settings.