Baba Kenji, Kawai Seiko, Iwase Satoshi, Ushida Takahiro, Tamura Yasuhiro, Arimoto Mariko, Nojiri Makiko, Watanabe Daisuke, Ban Nobutaro
Department of General Medicine, Medical Center, Aichi Medical University, 17-33 Kawagoe, Niki-cho, Okazaki 444-2148, Aichi, Japan.
Center of Medical Education, Aichi Medical University School of Medicine, 1-1 Yazakokarimata, Nagakute 480-1195, Aichi, Japan.
J Clin Med. 2024 Aug 24;13(17):5019. doi: 10.3390/jcm13175019.
The objectives were to investigate the clinical characteristics and course of long COVID, defined as the persistence of symptoms at least one month after the onset of COVID-19, in outpatients and to clarify differences in symptoms between SARS CoV-2 mutant strains. Our observational study in a primary care institution in Japan included 1053 patients with long COVID who visited our outpatient clinic between April 2021 and March 2023. Symptom distribution, performance status, and patient background at the time of the first outpatient visit were compared between infectious strains (Delta and before group and Omicron group). Background factors and symptoms related to time to remission were also analyzed. The severity of COVID-19 in the acute phase was mild, moderate, and severe in 82.2%, 14.9%, and 2.9% in the Delta and before group; and in 97.6%, 1.7%, and 0.4% in the Omicron group, respectively. Vaccination coverage was significantly different between the Delta and before (37.1%) and Omicron groups (73.1%) ( < 0.001), probably due to the period of vaccine unavailability in the former group. Symptoms of fatigue and headache occurred most frequently, irrespective of infectious strain. The mean number of symptoms per patient was significantly higher in the Delta and before group than the Omicron group (3.4 vs. 2.7, < 0.0001). The median time overall to remission of long COVID was 169 days. Cox hazard model analysis identified female sex, high body mass index, and dyspnea (but not infectious strain) as significant factors prolonging the time to remission ( < 0.05). Differences in the number of symptoms between infectious strains may be related to differences in viral virulence and/or vaccination coverage. However, the clinical course was found to be minimally influenced by the infectious strain. The present results should improve the understanding of prognosis in patients with long COVID from both the clinical and social perspectives.
目的是调查门诊患者中新冠后长期症状（定义为新冠病毒病发病至少一个月后症状持续存在）的临床特征和病程，并阐明严重急性呼吸综合征冠状病毒2（SARS-CoV-2）突变株之间症状的差异。我们在日本一家基层医疗机构开展的观察性研究纳入了2021年4月至2023年3月期间到我们门诊就诊的1053例新冠后长期症状患者。比较了感染毒株（德尔塔及之前毒株组和奥密克戎组）首次门诊就诊时的症状分布、体能状态和患者背景。还分析了与缓解时间相关的背景因素和症状。急性期新冠病毒病的严重程度，德尔塔及之前毒株组中轻症、中症和重症分别占82.2%、14.9%和2.9%；奥密克戎组中分别占97.6%、1.7%和0.4%。德尔塔及之前毒株组（37.1%）和奥密克戎组（73.1%）的疫苗接种率存在显著差异（<0.001），这可能是由于前一组存在疫苗供应不足的时期。疲劳和头痛症状出现最为频繁，与感染毒株无关。德尔塔及之前毒株组患者的平均症状数量显著高于奥密克戎组（3.4 vs. 2.7，<0.0001）。新冠后长期症状总体缓解的中位时间为169天。Cox风险模型分析确定女性、高体重指数和呼吸困难（而非感染毒株）是延长缓解时间的显著因素（<0.05）。感染毒株之间症状数量的差异可能与病毒毒力和/或疫苗接种率的差异有关。然而，发现临床病程受感染毒株的影响极小。本研究结果应能从临床和社会角度提高对新冠后长期症状患者预后的认识。
