Objective To understand the performance of etiological surveillance for influenza A and B in Jiading district of Shanghai, and provide reference for the prevention and control of influenza A and B.

Methods The incidence data of influenza-like illness (ILI) in Jiading from 2016 to 2023 were collected from a sentinel hospital in Shanghai for the descriptive and statistical analyses on the incidence of influenza A and B.

Results The predominant pathogens of influenza detected in a sentinel hospital in Shanghai from 2016 to 2023 varied with year. Influenza A and influenza B mainly occurred from December to April. There was no significant difference in the positive rate of influenza virus between men and women (χ²=0.752, P＞0.05), but there were significant differences among different age groups (χ²=51.465, P＜0.05). The highest positive rate of influenza A virus was 22.50% in age group ≥60 years (223/991), and the highest positive rate of influenza B virus was 9.90% in age group 25-＜60 years (511/5 164). ArcGIS map showed that the areas with high positive rate were in southern Jiading. The global spatial autocorrelation analysis showed a random distributions of the positive rates of influenza A and B viruses (Moran's I＞0,P＞0.05). Local spatial autocorrelation showed that there were high-low clustering of positive rate of influenza A virus in the southern part of the industrial zone, low-low clustering in Xinchenglu street, and no clustering of the positive rate in other areas. No clustering of positive rate of influenza B virus was not found. The routine blood test analysis showed that the means of white blood cell count, neutrophil count and C-reactive protein value were higher in influenza A cases than in influenza B cases, while the means of red blood cell count and lymphocyte count were higher in influenza B cases than in influenza A cases, the differences had significance (P＞0.05).

Conclusion The influenza A and influenza B cases showed different age and area distributions, and the routine blood test indicators varied. It is necessary to further strengthen the etiological surveillance in population at high risk and the season with high incidence and conduct routine blood test to provide evidence for the prevention and control of influenza.