Owen Branwen N, Elmes Jocelyn, Silhol Romain, Dang Que, McGowan Ian, Shacklett Barbara, Swann Edith M, van der Straten Ariane, Baggaley Rebecca F, Boily Marie-Claude
Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
Vaccine Clinical Research Branch, Division of AIDS, National Institutes of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, MD, USA.
J Int AIDS Soc. 2017 Jan 12;19(1):21162. doi: 10.7448/IAS.20.1.21162.
HIV is transmitted more effectively during anal intercourse (AI) than vaginal intercourse (VI). However, patterns of heterosexual AI practice and its contribution to South Africa's generalized epidemic remain unclear. We aimed to determine how common and frequent heterosexual AI is in South Africa.
We searched for studies reporting the proportion practising heterosexual AI (prevalence) and/or the number of AI and unprotected AI (UAI) acts (frequency) in South Africa from 1990 to 2015. Stratified random-effects meta-analysis by sub-groups was used to produce pooled estimates and assess the influence of participant and study characteristics on AI prevalence. We also estimated the fraction of all sex acts which were AI or UAI and compared condom use during VI and AI.
Of 41 included studies, 31 reported on AI prevalence and 14 on frequency, over various recall periods. AI prevalence was high across different recall periods for sexually active general-risk populations (e.g. lifetime = 18.4% [95%CI:9.4-27.5%], three-month = 20.3% [6.1-34.7%]), but tended to be even higher in higher-risk populations such as STI patients and female sex workers (e.g. lifetime = 23.2% [0.0-47.4%], recall period not stated = 40.1% [36.2-44.0%]). Prevalence was higher in studies using more confidential interview methods. Among general and higher-risk populations, 1.2-40.0% and 0.7-21.0% of all unprotected sex acts were UAI, respectively. AI acts were as likely to be condom protected as vaginal acts.
Reported heterosexual AI is common but variable among South Africans. Nationally and regionally representative sexual behaviour studies that use standardized recall periods and confidential interview methods, to aid comparison across studies and minimize reporting bias, are needed. Such data could be used to estimate the extent to which AI contributes to South Africa's HIV epidemic.
与异性阴道性交（VI）相比，HIV在肛交（AI）过程中的传播更有效。然而，异性肛交行为模式及其对南非广泛流行的艾滋病的影响仍不明确。我们旨在确定异性肛交在南非的普遍程度和频率。
我们检索了1990年至2015年期间报告南非异性肛交比例（患病率）和/或肛交及无保护肛交（UAI）行为数量（频率）的研究。采用按亚组分层的随机效应荟萃分析来得出合并估计值，并评估参与者和研究特征对肛交患病率的影响。我们还估计了所有性行为中肛交或无保护肛交的比例，并比较了阴道性交和肛交期间避孕套的使用情况。
在纳入的41项研究中，31项报告了肛交患病率，14项报告了频率，涉及不同的回忆期。在不同回忆期，性活跃的一般风险人群的肛交患病率较高（例如，终生患病率=18.4%[95%CI：9.——27.5%]，三个月患病率=20.3%[6.1——34.7%]），但在如性传播感染患者和女性性工作者等高风险人群中患病率往往更高（例如，终生患病率=23.2%[0.0——47.4%]，回忆期未说明=40.1%[36.2——44.0%]）。使用更保密访谈方法的研究中患病率更高。在一般和高风险人群中，所有无保护性行为中分别有1.2——40.0%和0.7——21.0%是无保护肛交。肛交行为使用避孕套保护的可能性与阴道性交行为相同。
报告显示异性肛交在南非人中很常见，但存在差异。需要开展全国性和地区性具有代表性的性行为研究，采用标准化的回忆期和保密访谈方法，以帮助进行研究间的比较并尽量减少报告偏倚。这些数据可用于估计肛交对南非艾滋病流行的影响程度。
