A multicenter study to identify the respiratory pathogens associated with exacerbation of chronic obstructive pulmonary disease in Korea.

Background Although respiratory tract infection is one of the most important trigger factors for acute exacerbation of chronic obstructive pulmonary disease (AE-COPD), there are limited data on the epidemiologic patterns of microbiology in South Korea. Methods A multicenter observational study was conducted in 28 hospitals in South Korea between January 2015 and December 2018. Adult COPD patients with moderate to severe acute exacerbations were eligible for the present study. They underwent all conventional tests to identify etiologic microbiologic pathogens. The primary outcome was the percentage of different microbiological pathogens that caused AE-COPD. Comparative microbiological analysis was performed between the patients with asthma-COPD overlap (ACO) and pure COPD. Results We included 1,186 patients with AE-COPD. Pure COPD patients were 87.9% and ACO patients were 12.1%. Nearly half of the patients used an ICS-containing regimen and one-fifth used systemic corticosteroids. Among them, respiratory pathogens were found in 55.3%. Bacteria and viruses were found in 33% and 33.2%, respectively. Bacterial and viral coinfections were found in 10.9%. The most frequently detected bacteria were Pseudomonas aeruginosa (9.8%), and the most frequently detected virus was influenza A (10.4%). Multiple bacterial infections were more likely found in ACO compared to pure COPD (8.3% vs 3.6%, p-value=0.016). Conclusion Distinct microbiological patterns were identified in patients with moderate to severe AE-COPD in South Korea. These findings may improve evidence-based management for AE-COPD and become the basis for further research related with infectious pathogens in COPD patients.