From the *Department of Medicine, University of Washington; †Public Health-Seattle & King County HIV/STD Program; ‡Department of Epidemiology, University of Washington, Seattle, WA.
Sex Transm Dis. 2017 Jul;44(7):385-389. doi: 10.1097/OLQ.0000000000000614.
Rectal sexually transmitted infections (STI) have been associated with human immunodeficiency virus (HIV) diagnosis, but inferring a causal association requires disentangling them from receptive anal intercourse (RAI).
We conducted a stratified case-control study by frequency matching 4 controls to each case within year using clinical data from men who have sex with men (MSM) attending the Seattle STD Clinic 2001 to 2014. Cases were MSM with a new HIV diagnosis and negative HIV test at 12 months or less. Controls were HIV-negative MSM. All included men had rectal STI testing, tested negative for syphilis, and had complete sexual behavior data. We categorized men by RAI: (1) none; (2) condoms for all RAI; (3) condomless RAI only with HIV-negative partners; and (4) condomless RAI with HIV-positive or unknown-status partners. We created 3 logistic regression models: (1) 3 univariate models of concurrent rectal gonorrhea, rectal chlamydia, and rectal STI in 12 months or less with new HIV diagnosis; (2) those 3 infections, plus age, race, year, number of sexual partners in 2 months or less, and methamphetamine use; and (3) model 2 with RAI categories. We calculated the population attributable risk of rectal STI on HIV diagnoses.
Among 176 cases and 704 controls, rectal gonorrhea, chlamydia and rectal STI in 12 months or less were associated with HIV diagnosis. The magnitude of these associations attenuated in the second model, but persisted in model 3 (gonorrhea: adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.3-3.8; chlamydia: aOR, 2.5; 95% CI, 1.5-4.3; prior STI: aOR, 3.0; 95% CI, 1.5-6.2). One in 7 HIV diagnoses can be attributed to rectal STI.
Rectal STI are independently associated with HIV acquisition. These findings support the hypothesis that rectal STI play a biologically mediated causal role in HIV acquisition and support screening/treatment of STI for HIV prevention.
直肠性传播感染（STI）与人类免疫缺陷病毒（HIV）诊断有关，但要推断因果关系，就需要将其与接受性肛交（RAI）区分开来。
我们通过按年对每个病例进行频率匹配，对在 2001 年至 2014 年间在西雅图性传播疾病诊所就诊的男男性行为者（MSM）进行了分层病例对照研究。病例为 HIV 新诊断且在 12 个月或更短时间内 HIV 检测呈阴性的 MSM。对照组为 HIV 阴性的 MSM。所有纳入的男性均接受了直肠 STI 检测，梅毒检测呈阴性，且具有完整的性行为数据。我们根据 RAI 将男性分为以下几类：（1）无；（2）所有 RAI 时均使用避孕套；（3）仅与 HIV 阴性伴侣进行无保护的 RAI；（4）与 HIV 阳性或未知状态的伴侣进行无保护的 RAI。我们创建了 3 个逻辑回归模型：（1）3 个单变量模型，分别为 12 个月或更短时间内同时患有直肠淋病、直肠衣原体和直肠 STI 与 HIV 新诊断的关系；（2）将 3 种感染、年龄、种族、年份、2 个月内性伴侣数量和使用冰毒纳入其中；（3）模型 2 加上 RAI 类别。我们计算了直肠 STI 对 HIV 诊断的人群归因风险。
在 176 例病例和 704 例对照中，12 个月或更短时间内患有直肠淋病、衣原体和直肠 STI 与 HIV 诊断相关。这些关联的幅度在第二个模型中减弱，但在第三个模型中仍然存在（淋病：调整后的优势比[aOR]，2.3；95%置信区间[CI]，1.3-3.8；衣原体：aOR，2.5；95% CI，1.5-4.3；既往 STI：aOR，3.0；95% CI，1.5-6.2）。每 7 例 HIV 诊断中就有 1 例可归因于直肠 STI。
直肠 STI 与 HIV 感染独立相关。这些发现支持直肠 STI 在 HIV 感染中具有生物介导的因果作用的假设，并支持对 STI 进行筛查/治疗以预防 HIV。
