Analysis of clinical characteristics of influenza virus pneumonia and risk factors for severe pneumonia in 711 Children / 国际儿科学杂志

ABSTRACT

Objective:To investigate the clinical characteristics of influenza A and influenza B pneumonia and the risk factors of severe influenza pneumonia in children.Methods:The epidemiology, clinical characteristics, laboratory tests and pathogens of co-infection in children with pneumonia caused by influenza A virus and influenza B virus, and the risk factors of severe influenza pneumonia were retrospectively analyzed.Results:(1) The cases of influenza A infection accounted for 65.1% and those with influenza B infection accounted for 32.9% among the 711 children with influenza pneumonia.The dominant strain was Influenza B Victoria virus in spring and summer, influenza A(H 3N 2) virus in autumn, and influenza A(H1N1) virus in winter.The dominant strain was influenza A virus at the age of < 1 year and ~3 years, influenza A virus and influenza B virus at the age of ~6 years, and influenza B virus at the age of ≥6 years.(2) The gastrointestinal symptoms were more common in children with influenza B pneumonia compared with those with influenza A pneumonia(53.4% vs 44.7%, χ2=4.728, P=0.030), but crackles and wheezing were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(80.1% vs 70.5%, 36.9% vs 25.6%, χ2=8.945, 8.093, all P<0.05). (3) The percentage of decreased lymphocyte count in children with influenza B pneumonia was higher than those with influenza A pneumonia(5.6% vs 1.9%, χ2=6.633, P=0.010). (4) Mixed Mycoplasma Pneumoniae was more common in children with influenza B pneumonia compared with those with influenza A pneumonia(23.9% vs 10.8%, χ2=20.789, P<0.001), and mixed virus and bacteria were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(15.8% vs 8.1%, 50.1% vs 41.9%, χ2=7.934, 4.221, all P<0.05). (5) Multivariate logistic regression analysis showed that age <2 years( OR=1.886, 95% CI 1.149~3.096, P=0.012), increased LDH( OR=1.736, 95% CI 1.080~2.790, P=0.023), the percentage of lymphocyte decreased( OR=2.762, 95% CI 1.669~4.571, P<0.001) and the percentage of CD3 + decreased ( OR=6.019, 95% CI 3.993~9.331, P<0.001)were risk factors for severe influenza pneumonia. Conclusion:Among hospitalized children with influenza pneumonia, there were some differences in the age of infection, clinical characteristics, laboratory tests and pathogens of co-infection between the cases caused by influenza B and influenza A, and clinicians should remain vigilant for the occurrence of severe influenza pneumonia.