EPIUnit, Institute of Public Health, University of Porto, Porto, Portugal.
Euro Surveill. 2015 Apr 9;20(14):21091. doi: 10.2807/1560-7917.es2015.20.14.21091.
HIV incidence in men who have sex with men (MSM) is increasing in western countries, including Portugal. We aimed to estimate HIV incidence and to assess how individual short-term changes in exposures over time predict seroconversion. We evaluated participants of an open cohort of HIV-negative MSM enrolled after testing at a community-based voluntary HIV counselling and testing centre in Lisbon. At each evaluation a structured questionnaire was completed and HIV status was ascertained using rapid followed by confirmatory testing. Between April 2011 and February 2014, 804 MSM were followed for a total of 893 person-years. Predictors of HIV seroconversion were identified using Poisson generalised linear regression. The overall seroincidence was 2.80/100 person-years (95% confidence interval: 1.89-4.14). Men who seroconverted had a higher mean number of tests per year. Seroconversions were significantly associated with partner disclosure of HIV status during follow-up, newly-adopted unprotected anal intercourse (UAI) with a steady partner and being newly-diagnosed with syphilis during follow-up. Likewise, sexual intercourse with HIV-positive men, having an HIV-positive steady partner at least once during follow-up and persistent UAI with occasional partners were predictors of seroconversion. High HIV incidence in this cohort is likely driven by short-term contextual and behavioural changes during follow-up.
在西方国家，包括葡萄牙在内，男男性行为者（MSM）中的 HIV 发病率正在上升。我们旨在估计 HIV 的发病率，并评估随着时间的推移，个体短期暴露变化如何预测血清转换。我们评估了在里斯本一个基于社区的自愿艾滋病毒咨询和检测中心检测后参加 HIV 阴性 MSM 开放队列的参与者。在每次评估中，都会完成一份结构化问卷，并使用快速检测和确认检测来确定 HIV 状态。在 2011 年 4 月至 2014 年 2 月期间，共有 804 名 MSM 随访了 893 人年。使用泊松广义线性回归确定了 HIV 血清转换的预测因素。总的血清发病率为 2.80/100 人年（95%置信区间：1.89-4.14）。血清转换的男性每年接受的检测次数平均值更高。在随访期间，伴侣告知 HIV 状态、新采用与稳定伴侣的无保护肛交（UAI）以及在随访期间新诊断为梅毒与血清转换显著相关。同样，与 HIV 阳性男性发生性关系、在随访期间至少有一次与 HIV 阳性稳定伴侣发生性关系以及与偶尔伴侣发生持续 UAI 是血清转换的预测因素。在这个队列中，HIV 发病率高可能是由于随访期间的短期环境和行为变化所致。
