Cowan Frances M, Pascoe Sophie J S, Langhaug Lisa F, Dirawo Jeffrey, Chidiya Samson, Jaffar Shabbar, Mbizvo Michael, Stephenson Judith M, Johnson Anne M, Power Robert M, Woelk Godfrey, Hayes Richard J
Centre for Sexual Health and HIV Research, University College London, London, UK.
Trop Med Int Health. 2008 Oct;13(10):1235-44. doi: 10.1111/j.1365-3156.2008.02137.x. Epub 2008 Sep 5.
To assess the effectiveness of a community-based HIV prevention intervention for adolescents in terms of its impact on (1) HIV and Herpes simplex virus type 2 (HSV-2) incidence and on rates of unintended pregnancy and (2) reported sexual behaviour, knowledge and attitudes.
Cluster randomised trial of a multi-component HIV prevention intervention for adolescents based in rural Zimbabwe. Thirty communities were selected and randomised in 2003 to early or deferred intervention implementation. A baseline bio-behavioural survey was conducted among 6791 secondary school pupils (86% of eligibles) prior to intervention implementation.
Baseline prevalences were 0.8% (95% CI: 0.6-1.0) for HIV and 0.2% (95% CI: 0.1-0.3%) for HSV-2. Four girls (0.12%) were pregnant. There was excellent balance between study arms. Orphans who made up 35% of the cohort were at increased risk of HIV [age-sex adjusted odds ratio 3.4 (95% CI: 1.7-6.5)]. 11.9% of young men and 2.9% of young women reported that they were sexually active (P < 0.001); however, there were inconsistencies in the sexual behaviour data. Girls were less likely to know about reproductive health issues than boys (P < 0.001) and were less likely to have used and to be able to access condoms (P < 0.001).
This is one of the first rigorous evaluations of a community-based HIV prevention intervention for young people in southern Africa. The low rates of HIV suggest that the intervention was started before this population became sexually active. Inconsistency and under-reporting of sexual behaviour re-emphasise the importance of using externally validated measures of sexual risk reduction in behavioural intervention studies.
评估一项针对青少年的社区艾滋病毒预防干预措施的效果,该干预措施对以下方面的影响:(1)艾滋病毒和2型单纯疱疹病毒(HSV-2)感染率以及意外怀孕率;(2)报告的性行为、知识和态度。
在津巴布韦农村地区对青少年进行的一项多成分艾滋病毒预防干预措施的整群随机试验。2003年选择了30个社区并将其随机分为早期或延迟干预实施组。在干预实施前,对6791名中学生(占符合条件者的86%)进行了基线生物行为调查。
艾滋病毒的基线患病率为0.8%(95%可信区间:0.6-1.0),HSV-2的基线患病率为0.2%(95%可信区间:0.1-0.3%)。有4名女孩(0.12%)怀孕。各研究组之间的平衡良好。占队列35%的孤儿感染艾滋病毒的风险增加[年龄-性别调整后的优势比为3.4(95%可信区间:1.7-6.5)]。11.9%的年轻男性和2.9%的年轻女性报告他们有性行为(P<0.001);然而,性行为数据存在不一致之处。女孩比男孩更不了解生殖健康问题(P<0.001),使用和能够获得避孕套的可能性也更小(P<0.001)。
这是对南部非洲一项针对年轻人的社区艾滋病毒预防干预措施的首批严格评估之一。艾滋病毒感染率较低表明该干预措施在这一人群开始性行为之前就已启动。性行为的不一致和报告不足再次强调了在行为干预研究中使用经外部验证的降低性风险措施的重要性。