Comparison of Clinical Presentations and Disease Severity of Children Hospitalized with Influenza A and B.

This study compared the clinical presentations and disease severity between influenza A and B (FLUA and FLUB). The study included children hospitalized with virologically confirmed influenza between 2010 and 2020. The severity of the disease was evaluated based on admission to the pediatric intensive care unit (PICU), mechanical ventilation requirement, length of hospital stay, length of stay in the PICU, and death. Influenza viruses were compared within predefined age groups (0-2, 3-9, and 10-18 years) and in all age groups. Of 343 patients, FLUA and FLUB were detected in 75.8% and 24.2% of children, respectively. FLUB was associated with a higher incidence of headache and abdominal pain (P < .001 and P = .01). Children with FLUB were prescribed antibiotics and antivirals 0.56 and 0.58- fold fewer than those with FLUA. Headache and abdominal pain rates were higher in patients between 3 and 9 years with FLUB. Children between 0 and 2 years with FLUA were more frequently admitted to the PICU than those with FLUB (23.6% vs. 4.0%; P < .004). Eight patients with FLUA died, while only 1 with FLUB died (P = .69). The clinical presentation of FLUA and FLUB appeared similar, except for headache and abdominal pain, which were more prevalent in older patients with FLUB. Our study revealed that children between 0 and 2 years with FLUA were at a significantly higher risk for admission to the PICU. As a result, greater attention and awareness should be paid to children under 2 years old with FLUA.