Prevalence, phenotype, and outcomes of virus PCR-positive severe acute exacerbations of chronic obstructive pulmonary disease (COPD)

Purpose : Viruses are recognized as etiologic agents of acute exacerbations (AE) of COPD. However, data on virus-induced severe AE (VSAE) requiring hospitalization remain limited. Given the significant costs of SAE and the development of effective vaccines, a better characterization of VSAE is essential. This study aimed to investigate the role of viruses in SAE and identify distinct characteristics of VSAE. Methods : We conducted a retrospective monocentric study of SAE during winter seasons at a tertiary care hospital. Nasopharyngeal swabs collected at admission were tested for 16 respiratory viruses using polymerase chain reaction (PCR). Cases with positive viral PCR results were classified as VSAE. Clinical, biological, and outcome data were compared between VSAE and virus PCR-negative SAE (non-VSAE). Results : There were 76 positive viral PCR (50%) among 153 admissions (139 patients). VSAE were predominantly associated with influenza (51%) and RSV (22%). COPD severity (GOLD stage) was similar between VSAE and non-VSAE.. At admission, VSAE more frequently presented with fever (45% vs. 26%; p=0.02) and had lower total white blood cell counts (10.7 ± 5.5 vs 12.4 ± 5.1× 10³/μL; p=0.04) and eosinophil counts (67 ± 123 vs 187 ± 322/μL; p<0.005). VSAE were associated with worse clinical outcomes, including longer hospital stays (17.8 ± 31.2 vs. 9.1 ± 9.2 days; p=0.02), increased systemic corticosteroid use (8.2 ± 7.9 vs. 5.2 ± 5.2 days; p<0.01), higher Intensive care unit (ICU) admission rates (30% vs. 12%; p<0.005), and more frequent endotracheal intubation (16% vs. 3%; p<0.005). Conclusion: Half of SAE cases were associated with viral infections, primarily influenza and RSV. VSAE were characterized by a higher prevalence of fever, lower eosinophil counts, and more severe clinical outcomes, including longer hospital stays and higher ICU admission rates. These findings emphasize the need for targeted prevention strategies, such as vaccination.