Objective: To study the epidemiological and clinical features of children with mild coronavirus disease 2019 (COVID-19).
Methods: The children who were diagnosed with mild COVID-19 in the Wuchang Shelter Hospital in Wuhan from February 5 to March 10, 2020 were enrolled as subjects. The clinical, laboratory, and lung imaging data were collected during hospitalization and isolation. This was a retrospective single-center case series analysis.
Results: A total of 1 124 patients with mild COVID-19 were admitted from February 5 to March 10, 2020, including 13 children (1.16%). All the 13 children (7 boys and 6 girls) were residents of Wuhan in China, with a median age of 16 years (range: 10-18 years). Of all the 13 children, 9(69%) were from family clusters of COVID-19 and 4(31%) had unknown sources of infection. The mean time from exposure to onset was 6.8 days (range: 2-13 days) in 9 children with a definite history of exposure. There were 6 symptomatic children with the main manifestations of fever, cough, weakness, and myalgia, and the mean time from onset to hospitalization was 9.2 days. Of all the 13 children, 7(54%) were asymptomatic with positive nucleic acid test of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). There were 4 children (31%) with abnormal lung CT findings, mainly patchy shadows or ground-glass opacities in the lung field, and 6 children (46%) had no symptoms with normal lung CT findings. All children had normal routine blood test results and C-reactive protein levels. Eight children underwent SARS-CoV-2 IgM and IgG tests at least once, among whom 6 had negative SARS-CoV-2 IgM but positive IgG, and 2 underwent SARS-CoV-2 IgM and IgG tests twice and had negative results. Of all the 13 children, 11(85%) had negative results of two SARS-CoV-2 nucleic acid tests during hospitalization and were discharged, and 2(15%) had positive results of four SARS-CoV-2 nucleic acid tests and were transferred to another hospital and lost to follow-up. Among the 11 children who were followed up, 1 had positive results of two SARS-CoV-2 nucleic acid tests at the isolation point, and 10 had negative results. The mean hospital stay was 10.9 days for the 13 children. Eleven children recovered during follow-up, with good living and learning conditions.
Conclusions: Children with mild COVID-19 often have an uncertain history of exposure and may not have any clinical symptoms. Etiological diagnosis is more important than clinical diagnosis. The disappearance of clinical manifestations may not parallel with the result of SARS-CoV-2 nucleic acid test. SARS-CoV-2 has a long detoxification time, and there may be recurrent cases of SARS-CoV-2 positivity. Further studies are needed to investigate the production patterns of SARS-CoV-2 IgM and IgG and their effect on the body.
目的: 探讨轻症2019-冠状病毒病（coronavirus disease 2019，COVID-19）患儿的流行病学和临床特征。
方法: 以2020年2月5日至3月10日武汉市武昌方舱医院确诊的轻症COVID-19儿童患者为研究对象，收集患儿住院期间和隔离期随访的临床、实验室、肺部影像学资料。该研究为回顾性、单中心系列病例分析。
结果: 2020年2月5日至3月10日期间，武昌方舱医院共收治轻症COVID-19患者1 124例，其中轻症儿童病例13例（1.16%）。13例患儿均为武汉市居民，中位年龄16岁（范围：10~18岁），男性7例，女性6例。家庭聚集性发病9例（69%），感染源不详4例（31%）。有明确接触史的9例患儿从接触感染源到发病平均时间为6.8 d（范围：2~13 d）。有症状患儿6例，主要表现为发热、咳嗽、乏力和肌肉疼痛。这6例患儿从发病到住院的平均时间为9.2 d。无症状、仅严重急性呼吸综合征冠状病毒-2（severe acute respiratory syndrome coronavirus-2，SARS-CoV-2）核酸检测阳性患儿共7例（54%）。肺部CT异常患儿共4例（31%），其影像学表现为肺野斑片状影或磨玻璃影。无症状且肺部CT正常的患儿共6例（46%）。所有患儿血常规及C-反应蛋白检测结果均正常。8例患儿进行了至少1次SARS-CoV-2 IgM和IgG检测，其中6例SARS-CoV-2 IgM阴性，而IgG阳性；2例2次SARS-CoV-2 IgM和IgG检测均为阴性。11例患儿（85%）在住院期间2次SARS-CoV-2核酸检测均阴性并出院；2例患儿（15%）4次SARS-CoV-2核酸检测均阳性，遂转院治疗，后失访。在11例随访患儿中，有1例在隔离点进行2次SARS-CoV-2核酸检测呈阳性，10例呈阴性。13例患儿平均住院时间为10.9 d。11例随访患儿均痊愈，生活及学习情况良好。
结论: 轻症COVID-19患儿存在如下特征：接触史多不确定，可能无临床症状；病原学诊断比临床诊断更为重要；临床表现消失和SARS-CoV-2核酸检测结果可能不平行，SARS-CoV-2排毒时间长，甚至可能出现SARS-CoV-2复阳病例；SARS-CoV-2 IgM和IgG的产生规律及其对机体的作用需进一步深入研究。