Abstract: ObjectiveTo describe the incidence trend and clinical characteristics of children with adenovirus infection in medical institutions in Shanghai. MethodsA cross-sectional study was designed to collect the demographic characteristics, clinical diagnosis and virological detection of children with adenovirus infection in outpatient and emergency settings and hospitalization in 38 medical institutions in Shanghai from January 1st, 2018 to May 31st, 2019，and compare the clinical characteristics of children with adenovirus infection in the same period of 2019 and 2018 (from January to May). ResultsA total of 618 children with adenovirus infection were included in this analysis. Sixteen patients (2.6%) were admitted to PICU and there were no deaths. There were 298 children with adenovirus positive detected in outpatient and emergency settings, including 176 male cases (59.1%) and 104 adenovirus pneumonia cases (34.9%). There were 320 hospitalized children, including 204 male cases (63.7%) and 278 adenovirus pneumonia cases (86.9%). In January of 2018 and 2019, the number of children with adenovirus infection in outpatient and emergency settings reached its peak. After January 2018, the peak of infection dropped rapidly, and from January to May in 2019 the peak decreased but still remained at a relatively high level. In 2019, compared with the same period in 2018 (from January to May), the incidence of pediatric adenovirus infection in outpatient and emergency settings and hospitalization increased by 1.8 times (148/84) and 2.3 times (157/69), respectively; the proportion of emergency visits increased (37.2% vs 9.5%); the mean age was younger (3.0 vs 4.0); the proportion of children under 2 years old was higher; the proportion of adenovirus pneumonia increased (50.0% vs 13.0%). There were statistically significant differences (P<0.05). Adenovirus detection methods in children's specialized hospital mainly include deep sputum antigen detection, the rapid detection of nasal swab antigen and serum IgM antibody detection. The detection methods of adenovirus in general hospital mainly include the rapid detection of nasal swab antigen and serum IgM antibody detection. ConclusionCompared with the same period of 2018 (from January to May), the incidence of adenovirus infection in Shanghai showed a higher trend in 2019 and lasted until May at least, with a higher proportion of adenovirus pneumonia and adenovirus infection in children under 2 years old.