Abstract
BACKGROUND: Infection prevention and control (IPC) measures during the coronavirus disease 2019 (COVID-19) pandemic have led to a reduction in respiratory viral infections. However, these infections showed a resurgence in the post-COVID-19 era. Respiratory viral infections often exacerbate respiratory diseases. OBJECTIVES: This study aimed to determine how the relaxation of IPC measures affects the incidence of virus-related acute exacerbations in various respiratory diseases. DESIGN: A retrospective study conducted at a tertiary care facility. METHODS: This study retrospectively assessed data from adult patients aged 18 years and older who visited the emergency department (ED) of a tertiary medical centre in Kobe, Japan, from 1 October 2020 to 12 March 2024. We identified patients who visited because of chronic obstructive pulmonary disease (COPD) exacerbation, asthma exacerbation or acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) and classified them into two groups based on the pre-relaxation and post-relaxation of IPC measures. The detection rates and respiratory viruses identified using multiplex polymerase chain reaction were compared between the groups. RESULTS: The total number of ED visits was 84,183 involving 129 cases of COPD exacerbation, 156 cases of asthma exacerbation and 68 cases of AE-IPF. Virus-related COPD exacerbations were significantly more frequent after the relaxation of IPC measures than before (7.7% vs 52.5%, p < 0.001). Similarly, virus-related asthma exacerbations occurred significantly more frequently after relaxation than before (39.7% vs 66.7%, p = 0.009). In contrast, no significant difference in the virus-associated AE-IPF was observed before and after relaxation (2.5% vs 5.0%, p = 0.61). CONCLUSION: Relaxation of IPC measures may increase virus-related exacerbations in COPD and asthma.