Immediate and long-term changes in the epidemiology, infection spectrum, and clinical characteristics of viral and bacterial respiratory infections in Western China after the COVID-19 outbreak: a modeling study

BACKGROUND: The impact of COVID-19 on the epidemiology, clinical characteristics, and infection spectrum of viral and bacterial respiratory infections in Western China is unknown. METHODS: We conducted an interrupted time series analysis based on surveillance of acute respiratory infections (ARI) in Western China to supplement the available data. RESULTS: The positive rates of influenza virus, Streptococcus pneumoniae, and viral and bacterial coinfections decreased, but parainfluenza virus, respiratory syncytial virus, human adenovirus, human rhinovirus, human bocavirus, non-typeable Haemophilus influenzae, Mycoplasma pneumoniae, and Chlamydia pneumoniae infections increased after the onset of the COVID-19 epidemic. The positive rate for viral infection in outpatients and children aged <5 years increased, but the positive rates of bacterial infection and viral and bacterial coinfections decreased, and the proportion patients with clinical symptoms of ARI decreased after the onset of the COVID-19 epidemic. Non-pharmacological interventions reduced the positive rates of viral and bacterial infections in the short term but did not have a long-term limiting effect. Moreover, the proportion of ARI patients with severe clinical symptoms (dyspnea and pleural effusion) increased in the short term after COVID-19, but in the long-term, it decreased. CONCLUSIONS: The epidemiology, clinical characteristics, and infection spectrum of viral and bacterial infections in Western China have changed, and children will be a high-risk group for ARI after the COVID-19 epidemic. In addition, the reluctance of ARI patients with mild clinical symptoms to seek medical care after COVID-19 should be considered. In the post-COVID-19 era, we need to strengthen the surveillance of respiratory pathogens.