Incidence and Prognostic Factors of Respiratory Viral Infections in Severe Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose: Severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD) that require hospitalization and emergency department visits are associated with considerable morbidity and mortality. Respiratory viral infection is an important cause of severe AECOPD. We evaluated the incidence and prognostic factors of viral infection in severe AECOPD. Patients and Methods: We performed a retrospective study of 262 cases of severe AECOPD in 192 patients who required hospitalization and emergency department visits at a tertiary teaching hospital in Daegu, Korea. A multiplex polymerase chain reaction panel using a nasopharyngeal swab sample was performed to detect viral infection. Results: Viral infection was detected in 108 events (41.2%) from 96 patients. The most common virus was rhinovirus/enterovirus (27.5%), followed by influenza virus (22.5%), respiratory syncytial virus (13.3%), parainfluenza virus (12.5%), coronavirus (12.5%), metapneumovirus (7.5%), and adenovirus (4.2%). Virus-positive exacerbations, compared to virus-negative exacerbations, had a higher frequency of symptoms of rhinopharyngitis, higher neutrophil count and C-reactive protein (CRP) level, and lower eosinophil count. Multivariate analysis demonstrated that elevated CRP levels (odds ratio [OR], 2.76; 95% confidence interval [CI], 1.24-6.15), symptoms of rhinopharyngitis (OR, 1.98; 95% CI, 1.03-3.78), low eosinophil count (OR, 1.74; 95% CI, 1.03-2.92), and inhaled corticosteroid (ICS) use (OR, 1.70; 95% CI 1.04-2.80) were associated with viral infection in severe AECOPD. Conclusion: The incidence of viral infection in severe AECOPD was 41.2%, and the most commonly detected virus was rhinovirus/enterovirus. Increased CRP level, symptoms of rhinopharyngitis, low eosinophil count, and use of ICS were associated with viral infection in severe AECOPD.