Department of Epidemiology and Biostatistics, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
Department of Community Medicine and Global Health, University of Oslo, Oslo, Norway.
Front Public Health. 2024 Jul 16;12:1405765. doi: 10.3389/fpubh.2024.1405765. eCollection 2024.
Pre-exposure prophylaxis (PrEP) prevention-effective adherence is of critical importance but challenging particularly among key populations where periods of high HIV risk are frequent. We assessed the use of PrEP with reference to periods of unprotected sex among female sex workers in the city of Tanga.
This was part of the pragmatic quasi-experimental trial for HIV PrEP rollout in Tanzania involving a control cohort of 313 female sex workers aged ≥18 years recruited by respondent-driven sampling and followed for 12 months. PrEP use and periods of condomless or unprotected sex were assessed at the 6th and 12th month of follow-up. Prevention-effective adherence was defined as PrEP use of ≥2 pills/week and ≥6 pills/week for anal and vaginal condomless sex. Multivariable modified Poisson regression was conducted to determine factors influencing PrEP use (≥2 pills/week).
Overall, 59.2 and 45.9% of participants had unprotected anal and vaginal sex with a client, respectively. The prevention-effective adherence for anal sex ranged from 8.0% (months 6) to 10.0% (months 12) while that of vaginal sex was from 10.1% (month 6) to 3.8% (month 12). Participants who lived with friends were 25.5 times more likely to use ≥2 PrEP doses per week than those who lived alone (aPR = 25.5; 95%CI: 2.55-255.42, = 0.006). Compared to self-reporting poor health status, self-reporting good health status significantly increased the use of ≥2 PrEP doses per week (aPR = 17.4; 95%CI: 3.01-101.02, = 0.001). Refusing condomless sex with a steady partner increased the likelihood of using ≥2 PrEP doses per week than accepting condomless sex with a steady partner (aPR = 11.2; 95%CI: 1.55-80.48, = 0.017). The prevalence of using ≥2 PrEP doses per week was less among participants accepting condomless sex at high pay than those who refused (aPR = 0.1; 95%CI: 0.03-0.26, = 0.000).
Use of PrEP during periods of unprotected sex was rare among female sex workers. Living with friends, self-reporting good health status, and refusing condomless sex with steady partners were associated with increased use of ≥2 PrEP doses per week. However, accepting condomless sex for increased payment was associated with reduced use of ≥2 PrEP doses per week. This calls for an in-depth study to understand the perspectives and circumstances shaping poor adherence during periods of unprotected sex among female sex workers.
暴露前预防（PrEP）的有效预防依从性至关重要，但在高危期频繁的关键人群中，这一问题极具挑战性。我们评估了坦噶市女性性工作者在无保护性行为期间使用 PrEP 的情况。
这是在坦桑尼亚开展 HIV PrEP 推广的实用类准实验性试验的一部分，其中包括通过应答驱动抽样招募的 313 名年龄≥18 岁的女性性工作者组成的对照队列，并对其进行了 12 个月的随访。在第 6 个月和第 12 个月的随访中评估 PrEP 的使用情况和无保护或未使用安全套的性行为。预防有效的依从性定义为每周至少使用 2 片或 6 片 PrEP 进行肛交和阴道无保护性行为。采用多变量修正泊松回归分析确定影响 PrEP 使用（每周≥2 片）的因素。
总体而言，分别有 59.2%和 45.9%的参与者与客户进行了无保护的肛交和阴道交。肛交的预防有效依从性从第 6 个月的 8.0%到第 12 个月的 10.0%，而阴道交的依从性从第 6 个月的 10.1%到第 12 个月的 3.8%。与独居者相比，与朋友同住的参与者更有可能每周使用≥2 剂 PrEP（调整后的发病率比[aPR]=25.5；95%CI：2.55-255.42， = 0.006）。与自报健康状况差相比，自报健康状况良好显著增加了每周使用≥2 剂 PrEP 的可能性（调整后的发病率比[aPR]=17.4；95%CI：3.01-101.02， = 0.001）。与接受稳定伴侣的无保护性行为相比，拒绝稳定伴侣的无保护性行为增加了每周使用≥2 剂 PrEP 的可能性（调整后的发病率比[aPR]=11.2；95%CI：1.55-80.48， = 0.017）。与拒绝高报酬的无保护性行为相比，接受高报酬的无保护性行为的参与者每周使用≥2 剂 PrEP 的比例较低（调整后的发病率比[aPR]=0.1；95%CI：0.03-0.26， = 0.000）。
在无保护性行为期间使用 PrEP 的情况在女性性工作者中很少见。与朋友同住、自报健康状况良好和拒绝稳定伴侣的无保护性行为与增加每周使用≥2 剂 PrEP 相关。然而，接受高报酬的无保护性行为与每周使用≥2 剂 PrEP 的比例降低有关。这需要进行深入研究，以了解影响女性性工作者在无保护性行为期间预防有效依从性的观点和情况。
