Pathogen Distribution and Infection Types Across Chronic Obstructive Pulmonary Disease Severity in a Cross-Sectional Study in Heyuan.

This cross-sectional study aimed to characterize the pathogen profile among hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in the Heyuan region and examine the distribution of infection types across severity grades defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). The study included 203 hospitalized patients with AECOPD from the largest comprehensive tertiary Grade A hospital in Heyuan. Pathogen screening was performed using serological antibody testing and sputum culture. The overall pathogen detection rate was 50.25%, while non-infectious factors accounted for 49.75%. Atypical pathogens were frequently detected, with Mycoplasma pneumoniae accounting for 35.96% and influenza virus for 11.82%. Mixed infections comprised 17.24%, and pure atypical pathogen infections represented 22.17%. Among the 109 AECOPD patients stratified by disease severity, simple viral and mixed pathogen infections had the highest combined proportions of severe and very severe cases (100.0% and 92.9%, respectively). These findings characterize pathogen detection patterns among hospitalized patients with AECOPD in Heyuan and demonstrate variation in infection types across GOLD severity grades. The findings should be interpreted cautiously because serological detection, particularly M. pneumoniae immunoglobulin G (IgG), cannot independently distinguish previous exposure from active infection. C-reactive protein (CRP) and procalcitonin (PCT) measurements may provide additional information when evaluating infection patterns; however, the observational study design does not establish treatment efficacy or support GOLD-stage-specific therapeutic recommendations.