Dynamic Shifts in Respiratory Pathogens During the First Post-COVID-19 Autumn-Winter in Beijing

Area of Science:

• Infectious Diseases
• Epidemiology
• Microbiology

Background:

• The COVID-19 pandemic significantly altered respiratory pathogen epidemiology.
• Respiratory infections surged in China after COVID-19 restrictions eased in December 2022.
• The study focuses on the first post-COVID-19 autumn-winter season in Beijing.

Purpose of the Study:

• To investigate the spectrum of respiratory pathogens.
• To analyze mixed infection patterns.
• To track temporal dynamics of respiratory pathogens in Beijing post-COVID-19.

Main Methods:

• Analysis of 864 throat swab specimens from patients with respiratory infections.
• Multiplex PCR used to detect 31 viral, bacterial, and atypical pathogens.
• Detection rates, co-infection patterns, and temporal trends analyzed across demographics and clinical settings.

Main Results:

• High detection rate of respiratory bacteria (79.63%), especially in children.
• Co-infections occurred in 59.16% of positive cases (viral-bacterial and bacterial-bacterial dominant).
• Influenza A (27.31%), Influenza B (10.42%), and *Haemophilus influenzae* (26.62%) were among the most detected pathogens.

Conclusions:

• The post-COVID-19 autumn-winter season in Beijing saw widespread co-circulation of multiple respiratory pathogens.
• High viral burden and frequent bacterial co-infections were observed.
• Emphasizes the need for continuous molecular surveillance and integrated testing for clinical and public health management.