Objective:To analyze the pathogen spectrum and epidemiological characteristics of acute respiratory infections in Yantai from 2024 to 2025.Methods:Influenza-like illness（ILI）and severe acute respiratory infection（SARI）patients were enrolled from the national sentinel hospitals for acute respiratory infectious diseases in Yantai between January 2024 and April 2025. Oropharyngeal swab samples were collected and 16 common respiratory pathogens were tested using real-time quantitative PCR. Descriptive epidemiological methods were used to analyze the detection results.Results:A total of 1 499 cases were included in the study，including 1 070 ILI cases and 429 SARI cases. The overall positive rate of respiratory pathogens was 52.57%（788/1 499）. All of the 16 targeted respiratory pathogens were detected，with influenza virus A（FluA），SARS-CoV-2， Haemophilus influenzae（ Hi），and human adenovirus（HAdV）being the predominant pathogens. The co-infection rate was 6.27%（94/1 499），with FluA combined with Hi infection being the predominant type. Statistically significant differences in the positive rates of influenza B virus and SARS-CoV-2 were observed between male and female patients（both P<0.05）. The overall positive rates varied significantly across different age groups（ P<0.001），with the highest rate（64.62%，84/130）observed in the 4-14 year age group. The overall positive rates also varied significantly among different months（ P<0.001），with the highest rate in December（69.93%，107/153）. The overall positive rate was 57.48%（615/1 070）in ILI cases and 40.33%（173/429）in SARI cases，with statistically significant difference between the two groups（ P<0.001）. Influenza viruses and SARS-CoV-2 were the predominant pathogens in ILI cases，whereas HAdV and Mycoplasma pneumoniae were more common in SARI cases. Conclusions:FluA，SARS-CoV-2， Hi，and HAdV are the predominant pathogens causing acute respiratory infections in Yantai from January 2024 to April 2025. The positive rates of respiratory pathogens varies across different gender and age groups，and shows distinct seasonal patterns. There are significant differences in pathogen spectra between ILI and SARI cases.

Objective:To analyze the pathogen spectrum and epidemiological characteristics of acute respiratory infections in Yantai from 2024 to 2025.Methods:Influenza-like illness（ILI）and severe acute respiratory infection（SARI）patients were enrolled from the national sentinel hospitals for acute respiratory infectious diseases in Yantai between January 2024 and April 2025. Oropharyngeal swab samples were collected and 16 common respiratory pathogens were tested using real-time quantitative PCR. Descriptive epidemiological methods were used to analyze the detection results.Results:A total of 1 499 cases were included in the study，including 1 070 ILI cases and 429 SARI cases. The overall positive rate of respiratory pathogens was 52.57%（788/1 499）. All of the 16 targeted respiratory pathogens were detected，with influenza virus A（FluA），SARS-CoV-2， Haemophilus influenzae（ Hi），and human adenovirus（HAdV）being the predominant pathogens. The co-infection rate was 6.27%（94/1 499），with FluA combined with Hi infection being the predominant type. Statistically significant differences in the positive rates of influenza B virus and SARS-CoV-2 were observed between male and female patients（both P<0.05）. The overall positive rates varied significantly across different age groups（ P<0.001），with the highest rate（64.62%，84/130）observed in the 4-14 year age group. The overall positive rates also varied significantly among different months（ P<0.001），with the highest rate in December（69.93%，107/153）. The overall positive rate was 57.48%（615/1 070）in ILI cases and 40.33%（173/429）in SARI cases，with statistically significant difference between the two groups（ P<0.001）. Influenza viruses and SARS-CoV-2 were the predominant pathogens in ILI cases，whereas HAdV and Mycoplasma pneumoniae were more common in SARI cases. Conclusions:FluA，SARS-CoV-2， Hi，and HAdV are the predominant pathogens causing acute respiratory infections in Yantai from January 2024 to April 2025. The positive rates of respiratory pathogens varies across different gender and age groups，and shows distinct seasonal patterns. There are significant differences in pathogen spectra between ILI and SARI cases.