To analyze the epidemiological characteristics of acute respiratory infections (ARIs) during the autumn-winter season in Beijing, providing evidence for the prevention, control, diagnosis, and treatment of ARIs.

A convenience sampling method was employed, enrolling patients who visited Peking Union Medical College Hospital (PUMCH) between September 2023 and February 2024 due to ARIs. Nasopharyngeal swabs were collected, and real-time fluorescence quantitative PCR was used to detect six common respiratory pathogens[influenza A virus (FluA), influenza B virus (FluB), human rhinovirus (HRV), Mycoplasma pneumoniae(MP), respiratory syncytial virus (RSV), and adenovirus(ADV)], as well as SARS-CoV-2 infection. The distribution patterns of pathogen infections were analyzed.

A total of 5556 eligible patients were included. The overall positivity rate for the six common respiratory pathogens was 63.7%, with single-pathogen positivity at 54.0%, dual-pathogen positivity at 8.9%, and triple or more pathogen positivity at 0.7%. The predominant pathogens detected were FluA(16.1%) and RSV(15.7%), followed by ADV(11.1%), MP(11.1%), HRV(10.0%), and FluB(10.0%).No significant difference in overall pathogen positivity was observed between genders.However, significant differences were found between autumn and winter(χ²=34.617, P < 0.001) and among pediatric, young/middle-aged, and elderly patients(χ²=422.38, P < 0.001).Specifically, MP(χ²=8.647, P=0.003), FluA(χ²=131.932, P < 0.001), and HRV(χ²=174.199, P < 0.001) exhibited significantly higher positivity rates in autumn than in winter, whereas FluB was more prevalent in winter(χ²=287.894, P < 0.001). In pediatric patients, MP, RSV, HRV, and ADV positivity rates were significantly higher than in young/middle-aged and elderly patients(all P < 0.001), whereas FluB was more common in young/middle-aged patients(both P < 0.001). The positivity rates of the six common respiratory pathogens significantly declined during the SARS-CoV-2 epidemic period, exhibiting an asynchronous seasonal pattern.

The prevalence of respiratory pathogens in Beijing is associated with age and season. Targeted preventive measures should be implemented in different seasons and for key populations.