Objective: To compare the clinical characteristics of different types of human adenovirus (HAdV)
infection in hospitalized children with acute respiratory
infection in Beijing, and to clarify the clinical necessity of adenovirus typing. Methods: In a cross-sectional study, 9 022 respiratory tract specimens collected from hospitalized children with acute respiratory
infection from November 2017 to October 2019 in Affiliated Children's Hospital, Capital Institute of Pediatrics were screened for HAdV by direct immunofluorescence (DFA) and (or)
nucleic acid detection. Then the Penton base, Hexon and Fiber gene of HAdV were amplified from HAdV positive specimens to confirm their HAdV types by phylogenetic tree construction. Clinical data such as laboratory results and imaging data were analyzed for children with predominate type HAdV
infection using t, U, or χ2 test. Results: There were 392 cases (4.34%) positive for HAdV among 9 022 specimens from hospitalized children with acute respiratory
infection. Among those 205 cases who were successfully typed, 131 were male and 74 were female, age of 22.6 (6.7, 52.5) months,102 cases (49.76%) were positive for HAdV-3 and 86 cases (41.95%), HAdV-7, respectively, while 17 cases were confirmed as HAdV-1, 2, 4, 6, 14 or 21. In comparison of clinical characteristics between the predominate HAdV type 7 and 3
infection, significant differences were shown in proportions of children with
wheezing (10 cases (11.63%) vs. 25 cases (24.51%)), white blood cell count >15 ×109/L (4 cases (4.65%) vs.14 cases (13.73%)), white blood cell count <5×109/L (26 cases (30.23%) vs.11 cases (10.78%)),
procalcitonin level>0.5 mg/L (43 cases (50.00%) vs. 29 cases (28.43%)), multilobar infiltration (45 cases (52.33%) vs.38 cases (37.25%)),
pleural effusion (23 cases (26.74%) vs. 10 cases (9.80%)), and severe adenovirus
pneumonia (7 cases (8.14%) vs. 2 cases (1.96%)) with χ²=5.11, 4.44, 11.16, 9.19, 4.30, 9.25, 3.91 and P=0.024, 0.035, 0.001, 0.002, 0.038, 0.002, 0.048, respectively, and also in length of
hospital stay (11 (8, 15) vs. 7 (5, 13) d, Z=3.73, P<0.001). Conclusions: HAdV-3 and 7 were the predominate types of HAdV
infection in hospitalized children with acute
respiratory tract infection in Beijing. Compared with HAdV-3
infection, HAdV-7
infection caused more obvious inflammatory reaction, more severe pulmonary symptoms, longer length of
hospital stay, suggesting the clinical necessity of further typing of HAdVs.