Severe influenza virus infection in children admitted to the PICU: Comparison of influenza A and influenza B virus infection

Although the influenza virus usually causes a self-limiting disease, deaths are reported even in children without risk factors. We aimed to identify the clinical features, mortality associated with severe influenza A and B virus infections of children admitted to the pediatric intensive care unit (PICU). We conducted a retrospective study of children with confirmed influenza infection between 2012 and 2019 who were admitted to the PICU. Demographic features, risk factors, clinical data, microbiological data, complications, and outcomes were collected. Over seven influenza seasons (2012-2011 to 2015-2016), 713 children diagnosed with laboratory-confirmed influenza-related LRTI, and PICU admission was needed in 6% (46/713) of the patients. Thirty-one patients (67.4%) were diagnosed with influenza A and 15 patients were diagnosed with influenza B. Epidemiologic and clinical characteristics were similar in both influenza types, lactate dehydrogenase levels were significantly higher for influenza A than for influenza B infections. Although the influenza A to B ratio among the patients admitted to the PICU was 2.06, the percentage of cases requiring PICU admission was nearly two times higher in influenza B cases. There was no statistically significant difference in disease severity and complications in patients with influenza A and influenza B.