McGrath N, Nyirenda M, Hosegood V, Newell M-L
Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, London, UK.
Sex Transm Infect. 2009 Apr;85 Suppl 1(Suppl_1):i49-55. doi: 10.1136/sti.2008.033324.
To identify factors associated with sexual debut and early age at first sex (AFS) among young men and women (12-25 years) in a population with a high prevalence and incidence of HIV in rural South Africa.
Longitudinal data from four rounds (2003-7) of a prospective population-based HIV and sexual behaviour survey in rural KwaZulu-Natal were used to investigate the distribution and predictors of earlier first sex. Survival analyses were used, and each analysis considered men and women separately.
Among the 4724 women and 4029 men who were virgins at the beginning of the period, the median AFS was 18.5 and 19.2 years, respectively. In multivariable models, factors associated with earlier AFS across gender were periurban residence (vs rural), ever use of alcohol and knowing at least one person who had HIV, while school attendance had a significant protective effect. Other factors were important for one gender only. Maternal death was significantly associated with earlier AFS for women, in the same way that paternal death was for young men, while mother's membership of the same household significantly delayed AFS of young men. The analysis of early first sex confirmed the same factors to be important as in the overall analyses for men and women.
Given the association of individual, household and community level factors with sexual debut, a multisectorial approach to prevention and targeting in youth programmes is recommended.
在南非农村地区艾滋病毒高流行率和高发病率的人群中，确定与青年男女（12 - 25岁）首次性行为及初次性行为早龄相关的因素。
利用夸祖鲁 - 纳塔尔农村地区基于人群的前瞻性艾滋病毒和性行为调查四轮（2003 - 2007年）的纵向数据，调查初次性行为较早的分布情况和预测因素。采用生存分析，每次分析分别考虑男性和女性。
在该时期开始时为处女的4724名女性和4029名男性中，初次性行为的中位数年龄分别为18.5岁和19.2岁。在多变量模型中，跨性别的与初次性行为早龄相关的因素包括城郊居住（相对于农村）、曾饮酒以及认识至少一名艾滋病毒感染者，而上学则具有显著的保护作用。其他因素仅对某一性别重要。母亲死亡与女性初次性行为早龄显著相关，同样，父亲死亡与年轻男性初次性行为早龄显著相关，而母亲与年轻男性同住显著延迟了年轻男性的初次性行为年龄。对初次性行为较早情况的分析证实，与总体分析中男性和女性相同的因素很重要。
鉴于个人、家庭和社区层面因素与首次性行为之间的关联，建议在青年项目中采用多部门预防和针对性方法。
