Analysis of the typing of adenovirus and its clinical characteristics in children with acute respiratory tract infection

BACKGROUND: The purpose of this study was to investigate the typing of adenovirus (AdV) infection in children hospitalized with acute respiratory tract infection (ARTI) and its clinical characteristics. METHODS: Samples from 7832 hospitalized children with ARTIs from January 2021 to June 2022 were tested by multiplex PCR for AdV. AdV hex neighborhood genes were amplified and sequenced for typing by nested PCR. RESULTS: Three hundred twenty-eight cases were positive for AdV with rate of 4.48% (328/7832). No statistical difference in the rate of AdV detection was observed in different ages (P > 0.05). Among the 328 cases, 305 cases underwent amplification and sequence determination of AdV five-neighborhood, six-neighborhood and fibronectin genes. Only 237 cases were sequenced successfully for all 3 genetic fragments. The typing results of 231 cases with 3 genes were consistent, with 49.78% (115/231) of type 3, 41.56% (96/231) of type 7 and 8.66% (20/231) of other types identified. The main clinical symptoms in 231 children hospitalized with ARTI who were AdV positive were cough, sputum not easily coughable, Wheezing or shortness of breath and fever. Clinical diagnoses of 231 cases included: acute bronchitis 3.03% (7/231), capillary bronchitis 16.45% (38/231), pneumonia (mild/severe) 76.62% (177/231) (68.40% (158/231) in mild and 8.23% (19/231) in severe cases), bronchial asthma combined with pulmonary infection 3.46% (8/231). Higher percentage of shortness of breath, multilobar infiltration, and pleural effusion were found in type 7. Calcitoninogen in type 7 were significantly higher than those of type 3 and other types, and the white blood cell count was lower than those of type 3 and other types, and the difference was statistically significant (P < 0.05). CONCLUSION: AdV type 3 and 7 were frequently found in hospitalized children with acute lower respiratory tract involvement. AdV type 7 seems to be associated with more severe outcome.