Intensive longitudinal follow-up of cisgender and transgender women engaged in sex work during the three months following initiation of daily oral PrEP: A series of case-studies with mixed-method assessments

Pre-exposure prophylaxis (PrEP) usage among cisgender and transgender women sex workers in Europe is low. This mixed-methods study examined the daily experiences of woman sex workers using PrEP, with emphasis on understanding the dynamic process of initiating and sustaining PrEP adherence. We employed an intensive longitudinal design with daily assessments of self-reported use of daily oral PrEP, side-effects, condom use, and number of clients over a 3-month period, followed by in-depth exit qualitative interviews that also explored PrEP initiation, communication with sex workers and clients, and stigma. Convenience sampling was used to enroll 15 sex workers (12 transgender and 3 cisgender women) presenting to a PrEP clinic in Madrid between November 2022 and January 2023, all from Latin America. We collected 1266 daily survey responses and 13 interviews. Quantitative results showed that average PrEP adherence was above 70%, with missed doses being randomly distributed, and that condom use and number of clients did not significantly change during the study period. Qualitative results showed that the main reason to start PrEP was concern about condom rupture and/or removal by clients. Facilitators of PrEP adherence included personal motivation, creation of daily routines, and use of personal alarms. Barriers to PrEP adherence included side effects from PrEP and its coingestion with other substances, and changes in daily routine related to work, and travel. Strict prescription protocols represented an additional layer of difficulty. Secondary gains included a feeling of empowerment and the opportunity to opt for condom substitution for economic benefit, personal pleasure, or the desire to foster a trusting relationship with long-standing clients. This involved few selected encounters and did not impact overall number of clients. PrEP communication was limited by PrEP and HIV stigma. We found a complex interplay of individual, occupational, and structural factors shaping early PrEP adherence among participants.