Comparing COVID-19 and Influenza Course in Hospitalized Children

The course of COVID-19 illness was likely to be less severe than of influenza in a study of hospitalized children.

Children hospitalized with COVID-19 shared some clinical features with those hospitalized for influenza but were more likely to have a less severe clinical course, in a study at one hospital in Turkey.

Kamil Yilmaz, MD, Department of Pediatrics, Dicle University School of Medicine, Diyarbakir, Turkey, and colleagues compared clinical and laboratory parameters, as well as the rates of intensive care and mechanical ventilation requirement by children hospitalized for either of the viral illnesses.

“A review of the literature indicates that a limited number of studies have compared these two diseases in children,” Yilmaz and colleagues indicate. “In the present study, we aimed to compare the clinical and laboratory features of the pediatric cases caused by SARS-CoV-2 and influenza viruses.”

The investigators conducted a retrospective review of the medical records of 164 children hospitalized with RT-PCR confirmed COVID-19 and 46 with Influenza A or B at the Dicle University Hospital between March and November 2020.The two groups did not differ significantly in age or gender.

The investigators note that the decision to refer children with RT-PCR confirmed COVID-19 for hospitalization is made by the Ministry of Health and family physicians during their 14-day isolation period; with those having mild symptoms continuing isolation at home, and those requiring further evaluation taken directly to the hospital by ambulance.

Yilmaz and colleagues found that the Influenza patients had a significantly longer period of hospitalization, higher rates of intensive care and ventilator support requirement, and higher mortality rate than those with COVID-19.

Among the patients hospitalized for COVID-19 (mean age 93.9±16.5 months) compared to those with influenza (mean age 87.5±12.4 months), the median length of hospitalization was 2 (1-14) days and 14 (1-74 days), respectively; and 3 (1.8%) vs 19 (41.3%) needed intensive care.Of those admitted to ICU, 2 (1.2%) of COVID-19 patients required mechanical ventilation and 2 (1.2%) died; compared to 16 (34.8%) of those with influenza requiring mechanical ventilation and 7 (15.2%) who died.

The most common clinical characteristics at admission for both groups were cough, fever, muscle pain, and malaise, but the rates in the influenza group were significantly higher: cough (80.4% vs 23.2%), fever (67.4% vs 20.7%), muscle pain (73.9% vs18.9%). Those with influenza also had higher rates of vomiting, sore throat, nasal discharge, and tachypnea.The investigators reported the groups had similar rates of headache, diarrhea and conjunctivitis symptoms.

Yilmaz and colleagues acknowledge that the study limitations include the substantially smaller number of patients with influenza than with COVID-19, and that the cohorts were drawn from patients of a single hospital.They also note that in two other studies comparing children with COVID-19 and influenza, one found no significant differences between the groups, and the other found a substantially higher rate of mortality with COVID-19.

The investigators also recognize distinct differences between the two illnesses, including the emerging cases of Multisystem Inflammatory Syndrome in Children (MIS-C) with COVID-19; and that the long-term complications of COVID-19in children remain unclear.

"Considering the rise in MIS-C cases, one should bear in mind that different results may emerge in the future or that the disease may lead to different outcomes as a result of possible mutations in the viral genome," Yilmaz and colleagues caution.