The epidemiological features of respiratory tract infection using the multiplex panels detection during COVID-19 pandemic in Shandong province, China

Respiratory tract infection is one of the most common reasons for both morbidity and mortality worldwide. High attention has been paid to the etiological tracing of respiratory tract infection since the advent of COVID-19. In this study, we aimed to evaluate the epidemiological features of pathogens in respiratory tract infection, especially during COVID-19 pandemic. A total of 7668 patients with respiratory tract infection who admitted to Qilu Hospital of Shandong University from March 2019 to Dec 2021 were retrospectively included. The respiratory tract specimens were detected using a commercial multiplex PCR-based panel assay for common respiratory pathogens including influenza A virus (Flu-A), influenza A virus H1N1 (H1N1), influenza A virus H3N2 (H3N2), influenza B virus (Flu-B), parainfluenza virus (PIV), respiratory syncytial virus (RSV), adenovirus (ADV), Boca virus (Boca), human Rhinovirus (HRV), Metapneumovirus (MPV), Coronavirus (COV), Mycoplasma pneumoniae (MP), and Chlamydia (Ch). The positive rates were compared using a chi-square test. Compared with 2019, the positive rate of pathogen detection during from January 2020 to December 2021 was significantly lower, especially the detection of Flu-A. The positive rate of respiratory pathogen strains was 40.18% during COVID-19 pandemic, and a total of 297 cases (4.69%) of mixed infection with two or more pathogens were detected. There was no statistical difference in the positive rate between male and female patients. However, the positive rates of infection were different among different age groups, with higher incidence of RSV in infancy and toddler group, and MP infection in children and teenager group. While, HRV was the most common pathogen in the adult patients. Moreover, Flu-A and Flu-B were higher in winter, and MP and RSV were higher in spring, autumn and winter. The pathogens such as ADV, BOCA, PIV, and COV were detected without significant seasonal distribution. In conclusion, respiratory pathogen infection rates may vary by age and season, regardless of gender. During the COVID-19 epidemic, blocking transmission routes could help reduce the incidence of respiratory tract infection. The current prevalence of respiratory tract infection pathogens is of great significance for clinical prevention, diagnosis and treatment.