Analysis of epidemiological characteristics of human coronavirus in hospitalized children with respiratory tract infection in Hebei region

Objective: To investigate the epidemiological characteristics of human coronavirus (HCoV) in hospitalized children with respiratory tract infection in Hebei region, providing evidence for the diagnosis and prevention of children with respiratory tract infection. Methods: A retrospective study was conducted on 1 062 HCoV positive children hospitalized for respiratory tract infection in Children's Hospital of Hebei Province from January 2015 to December 2020, aged from 33 days to 14 years, with a median age of 2 years. 27 932 (60.9%) were males and 17 944(39.1%) were females. And the gender, ages, seasonal distribution, HCoV-positive rates, co-detection distribution and clinical diagnosis of HCoV positive cases were analyzed by SPSS 25.0. Enumeration data were expressed by frequency and percentage; categorical variable were compared by the Pearson χ2test. Results: The overall HCoV-positive rate was 2.31% (1 062/45 876), which was 2.37% (662/27 932) in male children and 2.23% (400/17 944) in female children. There was no statistically significant difference between genders (χ²=0.916, P=0.339). Children at age groups<1 years (2.44%) and 1-<3 years (2.63%) had higher HCoV-positive rates than those at age groups 3-<5 years (1.97%) and ≥5 years (1.38%) (χ²=27.332,P<0.01). The HCoV-positive rates from 2015 to 2018 were 2.13%, 2.45%, 2.28% and 2.23%. The HCoV-positive rate of 2019 (1.71%) was significantly lower than in 2016 (χ²=12.05, P<0.01), 2017 (χ²=7.34, P=0.01) and 2018 (χ²=6.78, P=0.01), but there was no significant difference compared with 2015 (χ²=2.84, P=0.09). The HCoV-positive rate of 2020 (3.37%) was significantly higher than in 2015 (χ²=13.636, P<0.01), 2016 (χ²=11.099, P<0.01), 2017 (χ²=15.482, P<0.01), 2018(χ²=18.601, P<0.01) and 2019(χ²=45.580, P<0.01). The positive rate was highest in spring (March to May) in 2015 and 2017 to 2018. February to April and July to September of 2016 were the peak periods of positive detection. No obvious seasonal change was observed in 2019 and the HCoV-positive rate of 2020 was extremely low from January to July, following significantly increased from August to December. 26.37% (280/1 062) of HCoV were co-detected with other respiratory pathogens and the most frequently identified mixed detection was RSV. Three or more pathogens were detected in 7.34% (78/1 062) of the HCoV-positive samples. Bronchopneumonia and bronchiolitis were more frequently observed in the single HCoV positive (61.89% and 16.75%) children compared to co-detected children(34.29% and 9.64%)(χ²=63.394 and 8.228, P<0.01). However, compared to those with HCoV mono-detection, co-detected children were more likely to have severe pneumonia (4.6% and 47.14%) (χ²=280.171, P<0.01). Conclusions: HCoV is one of the respiratory pathogens in children in Hebei region and more prevalent in spring. The susceptible population of HCoV is mainly children under the age of 3 years old. HCoV often co-detects with other respiratory pathogens, and the co-infection is one of the risk factors of severe pneumonia in children with respiratory infection.