Department of Radiology, Chonnam National University Hospital, Gwangju, Korea.
Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea.
Radiology. 2023 Jul;308(1):e230653. doi: 10.1148/radiol.230653.
Background Differences in the clinical and radiological characteristics of SARS-CoV-2 Omicron subvariants have not been well studied. Purpose To compare clinical disease severity and radiologically severe pneumonia in patients with COVID-19 hospitalized during a period of either Omicron BA.1/BA.2 or Omicron BA.5 subvariant predominance. Materials and Methods This multicenter retrospective study, included patients registered in the Korean Imaging Cohort of COVID-19 database who were hospitalized for COVID-19 between January and December 2022. Publicly available relative variant genome frequency data were used to determine the dominant periods of Omicron BA.1/BA.2 subvariants (January 17 to June 20, 2022) and the Omicron BA.5 subvariant (July 4 to December 5, 2022). Clinical outcomes and imaging pneumonia outcomes based on chest radiography and CT were compared among predominant subvariants using multivariable analyses adjusted for covariates. Results Of 1916 confirmed patients with COVID-19 (mean age, 72 years ± 16 [SD]; 1019 males), 1269 were registered during the Omicron BA.1/BA.2 subvariant dominant period and 647 during the Omicron BA.5 subvariant dominant period. Patients in the BA.5 group showed lower odds of high-flow O requirement (adjusted odds ratio [OR], 0.75 [95% CI: 0.57, 0.99]; = .04), mechanical ventilation (adjusted OR, 0.49 [95% CI: 0.34, 0.72]; < .001]), and death (adjusted OR, 0.47 [95% CI: 0.33, 0.68]; <.001) than those in the BA.1/BA.2 group. Additionally, the BA.5 group had lower odds of severe pneumonia on chest radiographs (adjusted OR, 0.68 [95% CI: 0.53, 0.88]; = .004) and higher odds of atypical pattern pneumonia on CT images (adjusted OR, 1.81 [95% CI: 1.26, 2.58]; = .001) than the BA.1/BA.2 group. Conclusions Patients hospitalized during the period of Omicron BA.5 subvariant predominance had lower odds of clinical and pneumonia severity than those hospitalized during the period of Omicron BA.1/BA.2 predominance, even after adjusting for covariates. See also the editorial by Hammer in this issue.
背景 奥密克戎亚变体的临床和影像学特征差异尚未得到很好的研究。目的 比较在奥密克戎 BA.1/BA.2 或奥密克戎 BA.5 亚变体为主导时期住院的 COVID-19 患者的临床疾病严重程度和影像学严重肺炎。材料与方法 本多中心回顾性研究纳入了 2022 年 1 月至 12 月期间在韩国 COVID-19 影像学队列数据库中登记的因 COVID-19 住院的患者。使用公开的相对变体基因组频率数据来确定奥密克戎 BA.1/BA.2 亚变体（2022 年 1 月 17 日至 6 月 20 日）和奥密克戎 BA.5 亚变体（2022 年 7 月 4 日至 12 月 5 日）的主导时期。使用多变量分析，根据胸部 X 线和 CT 对主要亚变体的临床结果和影像学肺炎结果进行比较，并调整了协变量。结果 在 1916 例确诊 COVID-19 患者（平均年龄 72 岁±16 [标准差]；1019 例男性）中，1269 例患者在奥密克戎 BA.1/BA.2 亚变体主导时期登记，647 例患者在奥密克戎 BA.5 亚变体主导时期登记。BA.5 组患者需要高流量氧气支持的可能性较低（调整比值比 [OR]，0.75 [95%置信区间：0.57，0.99]； =.04）、机械通气（调整 OR，0.49 [95% CI：0.34，0.72]； <.001）和死亡（调整 OR，0.47 [95% CI：0.33，0.68]； <.001）的可能性低于 BA.1/BA.2 组。此外，BA.5 组的胸片严重肺炎的可能性较低（调整 OR，0.68 [95% CI：0.53，0.88]； =.004），CT 图像上的非典型肺炎的可能性较高（调整 OR，1.81 [95% CI：1.26，2.58]； =.001），高于 BA.1/BA.2 组。结论 与奥密克戎 BA.1/BA.2 主导时期相比，在奥密克戎 BA.5 亚变体主导时期住院的患者的临床和肺炎严重程度较低，即使在调整了协变量后也是如此。本期杂志还刊登了 Hammer 的社论。
