Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom.
Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montréal, Canada.
PLoS One. 2020 Feb 11;15(2):e0228849. doi: 10.1371/journal.pone.0228849. eCollection 2020.
As HIV is very effectively acquired during condomless receptive anal intercourse (AI) with serodiscordant and viremic partners, the practice could contribute to the high prevalence among female sex workers (FSW) in eSwatini (formerly known as Swaziland). We aim to estimate the proportion reporting AI (AI prevalence) among Swazi FSW and to identify the correlates of AI practice in order to better inform HIV prevention interventions among this population.
Using respondent-driven sampling (RDS), 325 Swazi FSW were recruited in 2011. We estimated the prevalence of AI and AI with inconsistent condom use in the past month with any partner type, and inconsistent condom use during AI and vaginal intercourse (VI) by partner type. Univariate and multivariable logistic regression models were used to identify behavioural and structural correlates associated with AI and AI with inconsistent condom use.
RDS-adjusted prevalence of AI and AI with inconsistent condom use was high, at 44%[95% confidence interval (95%CI):35-53%]) and 34%[95%CI:26-42%], respectively and did not vary by partner type. HIV prevalence was high in this sample of FSW (70%), but knowledge that AI increases HIV acquisition risk low, with only 10% identifying AI as the riskiest sex act. Those who reported AI were more likely to be better educated (adjusted odds ratio(aOR) = 1.92[95%CI:1.03-3.57]), to have grown up in rural areas (aOR = 1.90[95%CI:1.09-3.32]), have fewer new clients in the past month (aOR = 0.33[95%CI:0.16-0.68]), and for last sex with clients to be condomless (aOR = 2.09[95%CI:1.07-4.08]). Although FSW reporting AI in past month were more likely to have been raped (aOR = 1.95[95%CI:1.05-3.65]) and harassed because of being a sex worker (aOR = 2.09[95%CI:1.16-3.74]), they were also less likely to have ever been blackmailed (aOR = 0.50[95%CI:0.25-0.98]) or been afraid to walk in public places (aOR = 0.46[95%CI:0.25-0.87]). Correlates of AI with inconsistent condom use were similar to those of AI.
AI is commonly practised and condom use is inconsistent among Swazi FSW. Sex act data are needed to determine how frequently AI is practiced. Interventions to address barriers to condom use are needed, as are biomedical interventions that reduce acquisition risk during AI.
由于在与血清不一致和病毒载量高的性伴侣进行无保护的接受性肛交（AI）时，艾滋病毒非常容易传播，因此这种做法可能导致斯威士兰（前身为斯威士兰）的女性性工作者（FSW）中 HIV 感染率居高不下。我们旨在估计斯威士兰 FSW 中报告 AI（AI 流行率）的比例，并确定 AI 实践的相关因素，以便更好地为该人群提供 HIV 预防干预措施。
使用响应驱动抽样（RDS），于 2011 年招募了 325 名斯威士兰 FSW。我们估计了过去一个月内与任何类型的伴侣进行 AI 和 AI 与不一致的 condom 使用率，以及与 AI 和阴道性交（VI）的不一致 condom 使用率按伴侣类型。使用单变量和多变量逻辑回归模型来确定与 AI 和 AI 与不一致 condom 使用率相关的行为和结构因素。
RDS 调整后的 AI 和 AI 与不一致 condom 使用率均较高，分别为 44%[95%置信区间（95%CI）：35-53%]和 34%[95%CI：26-42%]，且不因伴侣类型而异。该 FSW 样本中的 HIV 感染率很高（70%），但对 AI 增加 HIV 感染风险的认识较低，只有 10%的人将 AI 视为风险最大的性行为。那些报告 AI 的人更有可能受过良好教育（调整后的优势比（aOR）=1.92[95%CI：1.03-3.57]），来自农村地区（aOR=1.90[95%CI：1.09-3.32]），过去一个月中新客户较少（aOR=0.33[95%CI：0.16-0.68]），并且最后一次与客户进行无保护的性行为（aOR=2.09[95%CI：1.07-4.08]）。尽管报告过去一个月内 AI 的 FSW 更有可能被强奸（aOR=1.95[95%CI：1.05-3.65]）和因性工作而受到骚扰（aOR=2.09[95%CI：1.16-3.74]），但他们也不太可能被勒索（aOR=0.50[95%CI：0.25-0.98]）或害怕在公共场所行走（aOR=0.46[95%CI：0.25-0.87]）。AI 与不一致 condom 使用率相关的因素与 AI 相似。
AI 在斯威士兰 FSW 中普遍存在， condom 使用率不一致。需要性行为数据来确定 AI 的实践频率。需要采取解决 condom 使用障碍的干预措施，以及减少 AI 期间获得风险的生物医学干预措施。
