瑞典一项研究称，感染新冠病毒的人在感染后数月内深静脉血栓形成和肺栓塞的风险明显增加，即使是轻症病例也不例外。研究人员发现，感染者在确诊新冠30天后，肺栓塞风险增加33倍，深静脉血栓形成风险增加5倍。

A man is given a coronavirus disease (COVID-19) test at pop-up testing site in New York City, US, April 11, 2022. [Photo/Agencies]

New observational research out of Sweden has tracked more than one million COVID-19 cases for months after their acute illness in order to determine how the disease influences subsequent risk of blood clots. The findings indicate COVID-19 significantly increases a person’s risk of deep vein thrombosis and pulmonary embolism in the months after infection.

瑞典一项观察研究对100多万新冠病例进行了数月追踪，以确定新冠是如何影响感染者随后出现血栓的风险的。研究结果表明，人们在感染新冠后几个月内深静脉血栓形成和肺栓塞的风险明显增加。

The large study, published in The BMJ, looked at health data from 1,057,174 positive COVID-19 cases. This covers every single positive recorded case in Sweden from the beginning of the pandemic up to May 2021. A control group of four million age- and sex-matched subjects not positive with COVID was generated to quantify the increase in risk for blood clots caused by infection.

这项研究样本庞大，对1057174新冠病毒阳性感染者的健康数据进行了分析，涵盖了瑞典从疫情暴发以来到2021年5月的所有阳性感染者。研究设置了一个对照组，从而量化感染新冠导致的血栓风险增加程度，对照组由400万年龄和性别相仿的受试者组成，这些受试者的新冠病毒检测结果未呈阳性。该研究发表在《英国医学杂志》上。

In the 30 days after an initial COVID-19 diagnosis the researchers found a 33-fold increase in pulmonary embolism risk, a five-fold increase in deep vein thrombosis (DVT) risk and a two-fold increase in general bleeding events. The heightened risk, compared to the uninfected control group, persisted 60 days for bleeding, 90 days for DVT, and 180 days for pulmonary embolism.

研究人员发现，感染者在最初确诊新冠30天后，肺栓塞风险增加33倍，深静脉血栓形成风险增加5倍，一般性出血事件风险增加2倍。与未感染新冠的对照组相比，出血风险升高持续60天，深静脉血栓形成风险升高持续90天，肺栓塞风险升高持续180天。

Factoring in acute disease severity, the researchers found those initially hit hardest with COVID-19 did experience greater long-term risk for blood clotting events. However, the increased risk was not zero in those experiencing mild COVID. Those with only a mild infection still showed a three-fold risk of DVT and a seven-fold risk of pulmonary embolism.

研究人员发现，重症感染者血栓形成的风险更大。但轻症感染者血栓形成的风险也有所增加。轻症患者的深静脉血栓形成风险增加3倍，而肺栓塞风险增加7倍。

While this new study is the most robust to investigate the relationship between blood clots and SARS-CoV-2 infection it is not the first to identify this association. A large UK study last year found similar signs when it compared rates of hematological and vascular events after COVID-19 to rates of those same events after COVID vaccination.

该项最新研究是探索血栓形成与新冠病毒感染之间相关度的最有力研究，但它并不是第一项发现这种关联的研究。2021年英国的一项大型研究也发现了类似迹象，该研究比较了感染新冠后与接种新冠疫苗后的血液血管疾病的发生率。

That study more generally found significant increases in rates of stroke, heart attack and blood clotting a month after a COVID infection. It also found these rates of adverse events were much higher after COVID-19 than after vaccination, validating the suggestion that the deleterious after-effects of COVID-19 are much more impactful than any potential harms caused by vaccination.

该研究更普遍地发现，在感染新冠一个月后，中风、心脏病发作和血栓的发生率显著增加。

研究还发现，在感染新冠后，这些疾病的发生率要比接种疫苗之后高得多，这验证了新冠后遗症的危害比接种疫苗造成的任何潜在危害的影响更大的观点。

Another UK study published last year found incidences of and deaths from thromboembolism doubled in the first six months of the pandemic compared to rates seen in the years prior.

去年发布的另一项英国研究发现，在新冠疫情发生的前六个月，血栓栓塞症的发病率和死亡率比前几年翻了一番。

Ioannis Katsoularis, an author on the new Swedish study from Umeå University, said the findings affirm the value of vaccination in reducing the likelihood and severity of COVID-19.

该最新研究的论文作者，瑞典于默奥大学的伊奥尼斯·卡苏拉里斯称，这些研究结果肯定了疫苗接种在降低感染风险和减少重症方面的价值。