Unit of Infectious Diseases, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy.
Centre for Clinical Research, Epidemiology, Modelling and Evaluation (CREME) Institute for Global Health UCL, London, UK.
AIDS. 2021 Jun 1;35(7):1103-1112. doi: 10.1097/QAD.0000000000002825.
Zero risk of linked HIV transmission in serodiscordant couples when the HIV-infected partner had viral load less than 200 copies/ml ('U status') was found in observational studies. We aimed at estimating the proportion of time in which 'U status' was maintained and identifying factors associated with the risk of losing it.
Observational cohort study.
We included participants in the ICONA cohort who had reached an established 'U status' (viral load ≤200 copies/ml for >6 months) as of December 2010. The outcome was the number of person-days of follow-up (PDFU) above a viral load greater than 200 copies/ml, relative to the total number of PDFU observed. A logistic regression model was used to identify factors independently associated with the risk of losing 'U status'.
Eight thousand, two hundred and forty-one persons living with HIV were included in the analysis who contributed 2 670 888 PDFU. Of these, 1648 (20%) were women, 768 (9%) were people who inject drugs (PWID), and 2066 (25%) were foreign-born. The median of viral load measurements was 9 (IQR: 4-15). Overall, only 3.1% of PDFU were observed when viral load was above 200 copies/ml. The proportion of PDFU with viral load more than 200 copies/ml was higher than average in women (5.3%), unemployed (5.4%), PWID (4.7%), and in people with more than three previous virologic failures (6.3%). These variables were significant predictors of losing 'U status' in the multivariable logistic regression.
Our results reinforce the validity of the U=U message in real-world setting. However, we identified subsets of our study population at higher risk of losing the 'U status' for whom additional efforts are needed.
在观察性研究中发现，当 HIV 感染者的病毒载量低于 200 拷贝/ml（“U 状态”）时，血清学不一致的夫妇之间不存在 HIV 传播的风险。本研究旨在估计“U 状态”持续时间的比例，并确定与失去“U 状态”相关的风险因素。
观察性队列研究。
我们纳入了 ICONA 队列中截至 2010 年 12 月已达到稳定“U 状态”（病毒载量≤200 拷贝/ml 且持续时间>6 个月）的参与者。主要结局是病毒载量超过 200 拷贝/ml 的随访人日数（PDFU）与观察到的总 PDFU 之比。采用逻辑回归模型确定与失去“U 状态”风险相关的独立因素。
共纳入 8241 名 HIV 感染者，共随访 2670888 人日。其中，1648 名（20%）为女性，768 名（9%）为注射吸毒者（PWID），2066 名（25%）为外国出生。病毒载量测量值的中位数为 9（四分位距：4-15）。总体而言，仅 3.1%的 PDFU 时病毒载量>200 拷贝/ml。女性（5.3%）、失业者（5.4%）、PWID（4.7%）和多次病毒学失败（6.3%）者的病毒载量>200 拷贝/ml 的 PDFU 比例高于平均水平。这些变量在多变量逻辑回归中是失去“U 状态”的显著预测因素。
本研究结果进一步证实了 U=U 信息在真实环境中的有效性。然而，我们发现研究人群中有一些亚组更有可能失去“U 状态”，需要对这些人群进行额外的努力。
