Bacterial-like inflammatory response in children with adenovirus leads to inappropriate antibiotic use: a multicenter cohort study

Purpose: To compare the clinical severity of Human Adenovirus (HAdV) infection with other viral diseases in a cohort of children, evaluating presentation, therapy, and outcome. Methods: We conducted a retrospective multicenter cohort study in Italian children hospitalized from January to December 2023 for respiratory symptoms. The study included children with HAdV infection presenting primarily with respiratory symptoms. Patients with isolated gastrointestinal involvement or coinfection with bacteria were excluded. Results: A total of 171 children were enrolled: 98 with HAdV infection (age 44.3 ± 37.9 months) and 73 with other viruses (age 20.4 ± 27.2 months). In the first group, 57.1% had a coinfection with one or more additional viruses. The most common symptoms were fever (89.8%), cough (73.5%) and sore throat (52%). Respiratory distress and hypoxemia were more frequent in the non-HAdV group. Children with HAdV infection demonstrated significantly higher C-reactive protein levels (50.8 ± 54.2 vs. 16.5 ± 33.8 mg/L, p < 0.001), experienced a longer duration of fever (4.9 ± 3.6 vs. 3.4 ± 2.3 days, p = 0.009) and were more likely to receive antibiotic treatment (77.6% vs. 27.4%, p < 0.001). No differences were observed in hospitalization stay, rate of complications, and ICU admission. Conclusions: Interestingly, our data suggests that HAdV-infected children exhibit a more pronounced inflammatory response despite experiencing less severe respiratory symptoms compared to other viruses. The presence of prolonged fever and a strong inflammatory response often leads to antibiotic overuse during the initial phase, when the viral etiology is yet to be confirmed. Early and accurate identification of HAdV infection is crucial to optimize treatment strategies and minimize unnecessary antibiotic use.