The Epidemiology and Clinical Burden of Human Adenovirus Respiratory Infections Among Hospitalized Children Under 5 Years in Jordan.

BACKGROUND: Human Adenovirus (HAdV) is a significant pathogen associated with severe acute respiratory infections, especially in children under 5. Despite its global impact, its epidemiological and clinical burden in Jordan, particularly post-COVID-19, is limited. METHODS: We conducted a multicenter cross-sectional study across 4 hospitals in Jordan from November 2022 to April 2023. Nasopharyngeal swabs were collected from children <5 years old hospitalized with respiratory symptoms. HAdV positivity was determined using real-time polymerase chain reaction. Demographic, clinical and laboratory data were analyzed to identify predictors of HAdV positivity and complications. RESULTS: Among 1000 enrolled participants (median age 9.68 months, 59% male), the HAdV positivity rate was 10.9%, highest in children 49-60 months of age. HAdV-positive cases had higher rates and longer duration of sore throat compared with HAdV-negative cases. Coinfections with respiratory syncytial viruses or influenza were present in 34.9% of HAdV-positive cases and were associated with increased rates of cough, wheezing and respiratory crackles. Logistic regression revealed lower odds of HAdV positivity in children under six months [odds ratio (OR) 0.31, P < 0.001], while invasive ventilation was associated with higher odds of positivity (OR 5.01, P < 0.001). HAdV infection without coinfection was associated with reduced odds of complications (OR 0.06, P < 0.001). CONCLUSIONS: This is the first comprehensive study in Jordan to document the epidemiologic and clinical burden of HAdV in children post-COVID-19. HAdV remains a major cause of respiratory morbidity, with significant coinfection rates. Further research is needed to explore the nonrespiratory manifestations, identify HAdV common local serotypes and genetic characteristics.