Objective To analyze the surveillance status of acute respiratory tract infection pathogens in Fengxian District of Shanghai, and to determine the pathogen spectrum and epidemiological characteristics of acute respiratory tract infection in the district.

Methods Case surveillance data from Fengxian Central Hospital were collected through the Shanghai Integrated Surveillance System for Acute Respiratory Infections, and respiratory specimens were collected from the 50^th week of 2022 to the 49^th week of 2023 for nucleic acid detection of 25 pathogens and bacterial culture testing. Case surveillance data from Fengxian Central Hospital were collected through the National Influenza Sentinel Surveillance System, and respiratory specimens were collected for nucleic acid detection of 5 pathogens.

Results The percentage seeking for medical visits of influenza-like illness (ILI) and severe acute respiratory infection (SARI) were 4.74% and 0.81%, respectively, with epidemic peaks in winter and spring. A total of 1 610 samples were detected, among which 354 were SARI cases, whose age of P₂₅ and P₇₅ quartiles were 44 years and 71 years, respectively, with a positive detection rate of 48.31%. Among the 1 256 ILI cases, the age of P₂₅ and P₇₅ quartiles were 21 years and 39 years, respectively. The positive detection rate of pathogens was 65.04% in 123 ILI cases under comprehensive surveillance of respiratory tract infection and 66.11% in 1 133 ILI cases under influenza surveillance. The positive rates of influenza and SARS-CoV-2 in SARI samples were 12.99% and 29.66%, respectively. The positive rates of influenza and SARS-CoV-2 in ILI case samples were 33.20% and 31.53%, respectively. Influenza virus concentrated in the winter and spring. The ILI and SARI cases had the highest positivity rates in the 6‒14 years old group and 15‒24 years old group, respectively.

Conclusion The main pathogens of respiratory tract infection in Fengxian District of Shanghai were SARS-CoV-2 and influenza virus. Special efforts should be made to monitor respiratory disease pathogens in the population under 24 years old, and surveillance of SARI cases aged ≥60 years should be strengthened. The influenza virus and SARS-CoV-2 are alternating, which is different from the past and requires a change in the previous prevention and control strategies.