Differences in Clinical Features and Laboratory Results between Adults and Children with SARS-CoV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children accounts for a small proportion of all infections and is usually mild or asymptomatic. There are few studies on the clinical characteristics of SARS-CoV-2 infection in children, and the causes of the low prevalence in children remain unclear. Herein, we compared the epidemiological and clinical characteristics of SARS-CoV-2 infection between adults and children. Fifty-two patients with Coronavirus Disease 2019 (COVID-19) were retrospectively analyzed, including 38 adults and 14 children. Their clinical information such as epidemiological exposure history, laboratory indicators, chest computed tomography (CT) performance, and number of SARS-CoV-2 positive days were analyzed and compared. In children, 5 (35.71%) had mild COVID-19 and 9 (64.29%) had common type, while, in adults, 9 (23.68%) cases were mild, and 29 (76.32%) were common COVID-19. Among them, family clustering infection accounted for 50% (7/14) of child cases and 23.68% (9/36) of adult cases. Epidemiological exposure history, clinical classification, clinical symptoms, chest CT manifestations, and number of SARS-CoV-2-positive days were not significantly different between children and adults. However, the percentage of neutrophils in adults was significantly higher than that in children (P<0.05). The percentage and absolute value of lymphocytes, platelet counts, aspartate aminotransferase, and aspartate aminotransferase/alanine aminotransferase in adults were lower than those in children (P<0.05). Conclusively, children infected with SARS-CoV-2 show the characteristics of family clustering, and the proportion of mild and asymptomatic infections is higher. For families with a history of epidemiological exposure, routine SARS-CoV-2 nucleic acid testing and chest CT examination should be performed in asymptomatic children to determine whether they are infected. Unlike adults, although the reduction of lymphocytes and platelets in children is not common, it is necessary to be alert to the increased risk of liver damage in children.