Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
J Acquir Immune Defic Syndr. 2019 Apr 15;80(5):585-589. doi: 10.1097/QAI.0000000000001962.
Incidence of syphilis continues to increase among HIV-positive men who have sex with men (MSM) in Ontario. Our objective was to determine the effect of acute syphilis on virologic failure (VF) among virally suppressed HIV-positive MSM taking antiretroviral therapy (ART) and determine if the relationship is confounded by drug use.
The OHTN Cohort Study is a voluntary cohort of people receiving HIV care in Ontario. Syphilis and viral load (VL) data were retrieved via linkage with the provincial laboratory.
Analyses included 2632 MSM from 2008 to 2015, on ART, with ≥1 questionnaire and 2 consecutive VL of <50 copies per milliliter 6 months apart. VF was defined as (1) VL of ≥1000 copies per milliliter or (2) 2 consecutive VLs of ≥200 copies per milliliter ≥1 month apart. We modeled acute syphilis as a time-varying covariate on VF using Poisson regression. Time-varying drug use was assessed for confounding using an iterative process where potential confounders were removed and then reintroduced into the model. Our model allowed for repeat observations using generalized estimating equations.
VF incidence was 3.5 per 100 person-years [95% confidence interval (CI): 3.4 to 4.2]. The rate ratio for VF for acute syphilis was 1.5 (95% CI: 0.9 to 2.4) in the unadjusted model; 1.6 (95% CI: 1.0 to 2.4) in the model adjusted for age, education, region, and income; and 1.2 (95% CI: 0.7 to 1.9) in the final model with additional adjustment for drug use.
Acute syphilis was not associated with VF among virologically suppressed MSM on ART. Consequently, ART may still reduce HIV transmission risk to sexual partners.
安大略省艾滋病毒阳性男男性行为者（MSM）中梅毒的发病率持续上升。我们的目的是确定急性梅毒对接受抗逆转录病毒治疗（ART）的病毒抑制的艾滋病毒阳性 MSM 发生病毒学失败（VF）的影响，并确定该关系是否因药物使用而复杂化。
OHTN 队列研究是一个自愿性的艾滋病毒感染者队列，在安大略省接受艾滋病毒护理。通过与省级实验室的联系，检索梅毒和病毒载量（VL）数据。
分析包括 2008 年至 2015 年期间接受 ART 治疗、至少有 1 次问卷调查和 2 次连续 VL ＜50 拷贝/毫升、间隔 6 个月的 2632 名 MSM。VF 定义为（1）VL ≥1000 拷贝/毫升或（2）连续 2 次 VL≥200 拷贝/毫升、间隔 1 个月。我们使用泊松回归模型将急性梅毒作为 VF 的时间变化协变量进行建模。使用迭代过程评估时间变化的药物使用是否存在混杂，在该过程中，潜在混杂因素被移除，然后重新引入模型。我们的模型允许使用广义估计方程进行重复观察。
VF 发生率为 3.5/100 人年[95%置信区间（CI）：3.4 至 4.2]。在未调整模型中，急性梅毒发生 VF 的比率比为 1.5（95%CI：0.9 至 2.4）；在调整年龄、教育程度、地区和收入后，比值比为 1.6（95%CI：1.0 至 2.4）；在最终模型中，比值比为 1.2（95%CI：0.7 至 1.9），并进一步调整了药物使用情况。
在接受 ART 的病毒学抑制的 MSM 中，急性梅毒与 VF 无关。因此，ART 仍可能降低性伴侣的 HIV 传播风险。
