Departments of Epidemiology, University of Washington, Seattle, WA, USA.
Sex Transm Dis. 2012 May;39(5):388-93. doi: 10.1097/OLQ.0b013e318248aa8a.
Although growing evidence suggests that condoms offer moderate protection against herpes simplex virus type 2 (HSV-2), inability to control for unknown or unmeasured confounders associated with sexual activity may reduce the accuracy of the estimates. The case-crossover design offers increased control of individual-level confounders, and was thus used with the aim of producing a more accurate estimate of the effect of condom use on HSV-2 acquisition.
Data were pooled from 6 prospective studies that measured HSV-2 status at enrollment and over follow-up, and included periodic self-reported condom use and sexual activity. Sexual activity contemporaneous with acquisition was assigned to a case period; earlier sexual activity was assigned to a control period. Conditional logistic regression was used to assess differences in behavior during the case and control periods.
One hundred ninety-one eligible participants acquired HSV-2 during follow-up. This approach detected a 3.6% increase in the odds of HSV-2 acquisition with each unprotected act (odds ratio = 1.036; 95% confidence interval: 1.021-1.052), but no increase in the odds of acquisition associated with protected acts (odds ratio = 1.008; 95% confidence interval: 0.987-1.030).
This analysis suggests that condoms offer significant protection against HSV-2 transmission.
尽管越来越多的证据表明避孕套能为预防单纯疱疹病毒 2 型（HSV-2）提供一定程度的保护，但无法控制与性行为相关的未知或未测量的混杂因素，可能会降低这些估计的准确性。病例交叉设计提供了对个体水平混杂因素的更好控制，因此被用于生成更准确的避孕套使用与 HSV-2 感染之间关系的估计。
数据来自 6 项前瞻性研究，这些研究在入组时和随访期间测量了 HSV-2 状态，并包括定期自我报告的避孕套使用情况和性行为。与感染同时发生的性行为被分配到病例期；更早的性行为被分配到对照期。条件逻辑回归用于评估病例期和对照期之间行为的差异。
191 名符合条件的参与者在随访期间感染了 HSV-2。这种方法检测到每次未保护性行为的 HSV-2 感染几率增加了 3.6%（比值比=1.036；95%置信区间：1.021-1.052），但与保护性行为相关的感染几率没有增加（比值比=1.008；95%置信区间：0.987-1.030）。
这项分析表明，避孕套能为预防 HSV-2 传播提供显著保护。
