华盛顿——根据一项美国研究，长新冠影响多个身体系统的人群，其改善可能性远低于总体康复估计所显示的水平，感染三年内仅不到五分之一的人经历了持续改善。
WASHINGTON – People whose long Covid-19 affects multiple body systems are far less likely to improve than overall recovery estimates suggest, with fewer than one in five experiencing sustained improvement within three years of infection, according to a US study.
研究人员追踪了1019名成年人，他们在初次感染一年后仍患有疑似长新冠。
Researchers followed 1,019 adults who still had probable long Covid-19 a year after their initial infection.
该研究于11月2日发表在《内科学年鉴》上，发现约一半参与者在随后三年内经历了持续的症状改善，而约四分之一实现了症状完全缓解。但预后因病情模式不同而存在巨大差异。
About half experienced sustained symptom improvement over the following three years, while roughly a quarter had complete symptom remission, the study, published on Nov 2 in Annals of Internal Medicine, found. But outcomes differed dramatically depending on the pattern of illness.
以嗅觉或味觉改变为主导症状的长新冠患者中，约60%在三年后有所改善；而症状影响多个身体系统的患者中，这一比例不足19%。
About 60% of people whose long Covid-19 was dominated by changes in smell or taste had improved by three years, compared with less than 19% of those with symptoms affecting multiple body systems.
长新冠可导致疲劳、认知障碍和劳累后不适——即即使轻微的体力或脑力活动后症状加重——以及涉及多个器官系统的问题。目前尚无获批治疗该病症的疗法。
Long Covid-19 can cause fatigue, cognitive impairment and post-exertional malaise – a worsening of symptoms after even modest physical or mental activity – along with problems involving numerous organ systems. There is no approved treatment for the condition.
这项研究是美国国家卫生研究院资助的“Recover”计划的一部分，追踪的症状包括疲劳、脑雾、头晕、心悸、呼吸急促以及嗅觉或味觉改变。
The study, part of the US National Institutes of Health-funded Recover initiative, tracked symptoms including fatigue, brain fog, dizziness, palpitations, shortness of breath and changes in smell or taste.
当参与者的症状评分在两次连续的研究随访中均保持在疑似长新冠阈值以下时，即被视为有所改善。
Participants were considered to have improved when their symptom score remained below the threshold for likely long Covid-19 at two successive study visits.
但未参与该研究的圣路易斯退伍军人事务医疗系统临床流行病学中心主任齐亚德·阿拉利表示，该评分系统对嗅觉或味觉丧失和慢性咳嗽赋予了相当大的权重。
But the scoring system gives substantial weight to loss of smell or taste and chronic cough, said Ziyad Al-Aly, director of the Clinical Epidemiology Centre at the VA St. Louis Health Care System, who wasn’t involved in the research.
他说，虽然这些症状是新冠感染的特征，但并非他所认定的长新冠相关慢性多系统疾病的核心特征。
Although characteristic of Covid-19 infection, those symptoms aren’t central features of the chronic multi-system illness he associates with long Covid.
“多系统组是一种完全不同的疾病，”Al-Aly说。“这是真正的长新冠，它将持续存在，而这些患者似乎并没有表现出强劲的康复轨迹。”这些发现还说明了在确定有多少人从长新冠中康复时存在的一个更广泛的问题：什么算作康复。
The multi-system group “is a different disease altogether,” Al-Aly said. “This is the real long Covid that will endure, and these patients do not appear to show a robust trajectory of recovery.”The findings also illustrate a broader problem in determining how many people recover from long Covid-19: what counts as recovery.
南安普顿大学公共卫生学教授Nisreen Alwan表示，该研究使用的症状指数是利用“Recover”计划的数据开发的，并未在其他人群中得到独立验证。长新冠症状也可能波动，出现好转期后又复发。
The symptom index used in the study was developed using data from the Recover initiative and hasn’t been independently validated in other populations, said Nisreen Alwan, a professor of public health at the University of Southampton. Long Covid-19 symptoms can also fluctuate, with periods of improvement followed by relapse.
Alwan和一位同事6月在《英国医学杂志》（BMJ）上撰文指出，定义不一致使得难以区分持久康复与暂时缓解。彭博社
Alwan and a colleague argued in the BMJ in June that inconsistent definitions make it difficult to distinguish lasting recovery from temporary remission. BLOOMBERG