Objectives: To study the epidemiological and clinical features of children with coronavirus disease 2019 (COVID-19) caused by Delta variant infection and their differences from children with ordinary COVID-19 (non-Delta variant infection).
Methods: Eleven children aged <14 years, who were diagnosed with COVID-19 caused by Delta variant infection from August to September 2021 were enrolled (variant group). Five children aged <14 years who were diagnosed with ordinary COVID-19 from February to March 2020 served as the control group. The epidemiological data, clinical features, and laboratory examination results were compared between the two groups.
Results: There was no significant difference in the proportion of children with clinical symptoms between the two groups (P>0.05). There were no significant differences in white blood cell count, lymphocyte count, and platelet count between the two groups (P>0.05), while the variant group had a lower neutrophil count than the control group (P<0.05). Lymphocytopenia was not observed in either group. Compared with the control group, the variant group had a higher proportion of children with an increase in creatine kinase isoenzyme (P<0.05), while there were no significant differences in the proportion of children with an increase in lactate dehydrogenase, D-Dimer, C-reactive protein or interleukin-6 between the two groups (P>0.05). Among the 9 children in the variant group, 5 tested positive for IgM antibody at week 2 after admission, and all children tested positive for IgG antibody. At week 3 after admission, the level of IgM antibody tended to decrease in 9 children, and the level of IgG antibody tended to decrease in 8 children.
Conclusions: Delta variant is more infectious. COVID-19 caused by Delta variant infection may cause more serious myocardial damage than ordinary COVID-19 in children. In children infected with Delta variant, IgG antibody appears at almost the same time as IgM antibody.
目的: 探讨儿童Delta变异株新型冠状病毒肺炎（coronavirus disease 2019，COVID-19）的流行病学及临床特征，分析其与儿童普通COVID-19的差异。方法: 回顾性选取2021年8~9月确诊的Delta变异株COVID-19和2020年2~3月确诊COVID-19的14岁以下儿童16例为研究对象。将16例患儿按照病毒变异情况分为变异组（n=11）与普通组（n=5），对两组流行病学、临床特征及实验室检查资料进行比较。结果: 临床症状发生比例在变异组与普通组间比较差异无统计学意义（P>0.05）。白细胞计数、淋巴细胞计数和血小板计数在两组间比较差异无统计学意义（P>0.05）；变异组中性粒细胞计数低于普通组（P<0.05）；两组均没有淋巴细胞减少病例。变异组肌酸激酶同工酶增高比例较普通组多见（P<0.05）；而乳酸脱氢酶、D-二聚体、C-反应蛋白、白细胞介素-6增高比例与普通组比较差异无统计学意义（P>0.05）。9例变异组患儿在入院第2周有5例检测出IgM抗体阳性，均检测出IgG抗体阳性；入院第3周9例患儿IgM抗体水平呈下降趋势，8例患儿IgG抗体水平呈下降趋势。结论: Delta变异株感染性增强，对儿童心肌的损害高于普通COVID-19。儿童感染Delta变异株后，IgG抗体出现时间与IgM抗体基本相同。.
Keywords: COVID-19; Child; Clinical feature; Delta variant.