Risk Factors for Severe Influenza in Children

Introduction: Influenza poses a significant risk of mortality among pediatric patients. However, the specific risk factors associated with severe influenza in children are not well-defined. Clarifying these factors is crucial for improving preventive strategies against infection. Methods: This retrospective study analyzed pediatric patients under 15 years old who were diagnosed with influenza infection at Vajira Hospital from January 1, 2018, to December 31, 2022. Multivariate analysis was utilized to identify factors associated with severe influenza. Results: The 5-year retrospective study revealed that 300 pediatric patients were diagnosed with influenza infection. The median age was 4 months (interquartile range, 2.00–8.75 months), with 50% of patients being female. Among them, 80 patients (26.67%) had underlying diseases, with chronic lung disease being the most prevalent (22 patients, 7.33%). Notably, 94% of the patients had not received the influenza vaccine. Severe influenza was found in 56 patients (18.67%). Underlying diseases (odds ratio, 7.37; P < 0.001), especially chronic lungs disease (adjusted odds ratio, 45.286; P < 0.001) and nosocomial infection (adjusted odds ratio, 3.29; P = 0.019) were identified as factors associated with severe influenza. Conclusions: One-fifth of pediatric influenza cases exhibited severe manifestations, with underlying diseases and nosocomial infection identified as significant risk factors for severe influenza. Close monitoring is warranted for these patients, and infection control measures should be emphasized to prevent nosocomial infections.