Objective  To investigate the distribution of severe acute respiratory tract virus infection in children and the etiological characteristics and circulation of the pathogens in Huzhou, Zhejiang province, from 2016 to 2019, and provide evidence for thye effective prevention and control, clinical diagnosis and treatment of severe acute respiratory tract virus infection.

  Methods  The throat swabs or lower respiratory tract samples were collected from children aged ≤14 years with severe acute respiratory tract infections for the detections of 13 viruses with fluorescence multiple PCR. The results were analyzed by using SPSS 22.0.

  Results  According to the annual analysis, the positive detection rates of acute respiratory tract virus infection in children from 2016 to 2019 were 57.27%, 46.22%, 32.71% and 31.99%, respectively, the differences in annual positive detection rate had significance (P<0.05). The overall positive detection rate was 41.90%. The top three pathogens were respiratory syncytial virus (8.98%), influenza A virus (7.60%) and human adenovirus (5.94%). The positive detection rates of respiratory tract virus infection in spring, summer, autumn and winter were 43.65%, 30.75%, 40.73% and 49.67%, respectively, the differences had significance (P<0.05). The positive detection rates of respiratory tract virus infection were higher in winter and spring. The positive detection rates were 50.84%, 52.98%, 43.00% and 36.22%, respectively, in age groups 0, 1, 4, and 7–14 years. the differences were significant (P<0.05). The positive detection rates in age groups 0 and 1 year were significantly higher than those in age groups 4 and 7–14 years. The positive detection rate was 42.06% in males and 41.69% in females, the difference was not significant (P=0.864).

  Conclusion  The positive detection rate of viruses in children with acute respiratory tract infection showed a downward trend and the infection mainly occurred sporadically from 2016 to 2019, but the positive detection rate was still high. Children under 1 year old are more likely to be infected with respiratory virus. Winter and spring are still the season with high incidence of respiratory infections in children. It is necessary to pay close attention to acute respiratory tract virus infection in children.