Clinical significance of various pathogens identified in patients with acute exacerbations of COPD: a multi-center study in South Korea.

Background: Respiratory infection is a major cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We investigated the presence of bacterial and viral pathogens and clinical features in patients with AECOPD.

Methods: This retrospective study included 1,186 patients diagnosed with AECOPD from 28 hospitals in South Korea between 2015-2018. Pathogen identification rates, basic characteristics and clinical features, and associated factors for infection with potentially drug-resistant (PDR) pathogens were evaluated using microbiological tests.

Results: Bacteria, viruses, and both were found in 262 (22.1%), 265 (22.5%), and 129 (10.9%) patients, respectively. The most common pathogens were Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). A history of pulmonary tuberculosis (OR 1.66; P=0.046), bronchiectasis (OR 1.99; P=0.032), and triple inhaler use within six months (OR 2.04; P=0.005) were significant associated factors for PDR pathogen infection. Hospital stay length (15.9 days vs. 12.4 days; P=0.018) and ICU admission rates (15.9% vs. 9.5%; P=0.030) were increased in patients infected with PDR pathogens.

Conclusions: This study indicates that various types of pathogens are implicated during AECOPD. However, further research is needed to confirm whether these pathogens influence AECOPD development and progression.