[Clinical characteristics of convalescent children infected with SARS-CoV-2 Omicron variant in Tianjin].

ABSTRACT

Objective: To analyze the clinical characteristics of SARS-CoV-2 Omicron variant infected children in convalescence in Tianjin. Methods: A total of 104 pediatric patients infected by SARS-CoV-2 Omicron variant Tianjin First Central Hospital (designated hospital for SARS-CoV-2 infection in Tianjin) for convalescent treatment from January 22nd, 2022 to February 24th were included for a retrospective study.Clinical data including clinical typing, SARS-CoV-2 IgG and IgM test and 2019-nCoV nucleic acid test were collected.The cases were divided into 2-dose group and zero-dose group based on the doses of inactivated SARS-CoV-2 vaccine. The children were divided into repositive group and negative group, according to the nucleic acid test during hospitalization. Chi-square test was used for the comparison between the groups. Results: The age of these 104 children was 10.0 (0.3, 14.0) years on admission, 53 children were males and 51 were females, 92 cases (88.5%) had mild symptoms, 12 cases (11.5%) had common symptoms.The age and SARS-CoV-2 IgG level of zero-dose group was lower (2.0 (0.3, 10.2) vs. 10.0 (3.2, 14.0) years, 10 (2, 17) vs. 193 (157, 215), χ²=-5.57, Z=-48.76,both P<0.001) than that of 2-dose group. The zero-dose group had a high rate of transmission among family members and a high level of SARS-CoV-2 IgM level (13/14 vs. 62.2% (56/90), 0.4 (0.2, 0.8) vs. 0.4 (0.2, 1.1),χ²=5.09, Z=-48.95, both P<0.05) than the 2-dose group. Repositive group had a high rate of underlying diseases and SARS-CoV-2 IgM level was higher (2/13) vs. 1.1% (1/91), (0.6 (0.2, 1.0) vs. 0.3 (0.2, 0.7), χ²=8.29, Z=2.70, both P<0.05) than negative group. The SARS-CoV-2 IgG level of repositive group was lower than that of negative group (160 (78, 197) vs. 213 (186, 231), χ²=-3.20, P<0.05). Conclusions: Children infected with SARS-CoV-2 Omicron variant in Tianjin were mainly transmitted by family members, and most of them had mild symptoms. Two-dose group had higher IgG levels and lower IgM levels than zero-dose group.The probability of SARS-CoV-2 nucleic acid test repositivity increased in children with underlying diseases and lower IgG levels.