Epidemiology of respiratory tract infections using multiplex PCR in a Japanese acute care hospital during the COVID19 pandemic.

INTRODUCTION

We aimed to investigate the epidemiology of respiratory infections by season and age during the COVID-19 pandemic in a Japanese acute care hospital using multiplex PCR testing.

METHODS

We detected 21 pathogens in specimens from outpatients with respiratory symptoms at the Nara Prefecture General Medical Center using the multiplex PCR-based FilmArray Respiratory Panel 2.1 (bioMérieux).

RESULTS

Of the 3177 cases, 1215 (38.2%) were infected with at least one causative virus, and 1641 viruses were detected. The most common viruses detected were human rhinovirus/enterovirus (n = 655) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 264). Additionally, 321 (10.1%) of these cases were infected with two or more overlapping viruses. There were 23 cases of co-infection with SARS-CoV-2 and other viruses. In the winter months from December 2020 to March 2021, the number of detected viruses was relatively low, followed by the surge of human rhinovirus/enterovirus, respiratory syncytial virus (RSV), and parainfluenza type 3 in the spring and summer of 2021. While the number of human rhinovirus/entero-virus remained relatively high after the 2021 summer, the number of other viruses detected since September 2021 was low. After December 2021, the number of SARS-CoV-2 increased rapidly.

CONCLUSIONS

Continuous monitoring of the epidemiology of respiratory infection is important to understand the prolonged impact of the COVID-19 pandemic.