Virus profiling of bronchoalveolar lavage fluid in hospitalized non-COVID-19 adult patients with pulmonary infection from November 2020 to November 2021

Identifying the cause of respiratory tract infections is important for reducing the burden of diagnosis and treatment. To assess viral etiologies of hospitalized patients with pulmonary infection, bronchoalveolar lavage fluid (BALF) specimens were collected from non-COVID-19 adult patients (n ​= ​333, including patients with lower respiratory tract infection, tuberculosis, lung cancer, and pulmonary nodules) between November 2020 and November 2021. Multiple common respiratory pathogens were detected using multiplex reverse-transcription polymerase chain reaction. The result showed that at least one virus was identified in 35.44% (118/333) of the cases. Among these, influenza virus was the most commonly identified, followed by the parainfluenza virus, coronavirus, human rhinoviruses, and human respiratory syncytial viruses. The tuberculosis group demonstrated the highest viral detection rate, yet paradoxically exhibited the lowest co-infection rate. In contrast, the highest co-infection frequency was observed in the pulmonary nodules group. Patients with viral infections exhibited more severe clinical symptoms compared to those without detected viral infections. However, this observation was only noted in the lower respiratory tract infection group among the different disease groups. Notably, among patients infected with a specific virus, there were no significant differences in viral load between single and co-infections. Our study identified the major causative agents in hospitalized adult patients with pulmonary infection, offering insights for precise disease diagnosis and the prevention of unnecessary use of antimicrobial drugs.