A Multi-center Study to Determine the Prevalence and Influence of Pertussis on COPD Exacerbation in Shenzhen

Inclusion Criteria: \- Clinical diagnosis of acute COPD Exclusion Criteria: \- Major diseases except COPD; Significant abnormality in laboratory examination; Clinical diagnosis of lung cancer, bronchiectasis, pneumoconiosis or other simple restrictive ventilation dysfunction; Patients with a history of asthma, allergic rhinitis, or a blood eosinophil count of 2600/mm3 (0.6x10\^9/L) within 4 weeks; Currently suffering from active tuberculosis; Patients with life-threatening pulmonary embolism, or al-antitrypsin deficiency, or cystic fibrosis; Patients who have undergone lung resection.