[Clinical analysis of chest infections caused by streptococcus anginosus group]

Objective: To clarify the clinical characteristics of chest infections caused by streptococcus anginosus group (SAG). Methods: A total of 26 patients diagnosed in Affiliated Hospital of Jining Medical University from January 2014 to October 2019 were enrolled. The analyzed clinical data included baseline data, clinical symptoms, imaging manifestations, therapies, and outcomes. The microbiological diagnosis was established based on the specimens collected by lung needle biopsy, bronchoscopy, artificial airway aspiration, thoracentesis or thoracoscopy. Results: Among the 26 patients, there were 23 (88.5%) males and 3 (11.5%) females aged (63.0±12.5) years, and 21 cases (80.8%) had potential diseases. The distribution of clinical manifestations included 21 cases (80.8%) with fever, 13 cases (50.0%) with pectoralgia, 13 cases (50.0%) with cough, and 13 cases (50.0%) with expectoration. Chest CT displayed 18 cases (69.2%) with nodules, 18 cases (69.2%) with pleural effusion, 17 cases (65.4%) with patchy shadows, 12 cases (46.2%) with consolidation, 4 cases (15.4%) with cavity, 3 cases (11.5%) with spontaneous pneumothorax. 13 cases (50.0%) of Streptococcus constellatus, 12 cases (46.2%) of Streptococcus anginosus and 1 case (3.8%) of Streptococcus intermadius were observed through the bacterial culture. After anti-infection treatment and invasive operation (including tracheoscopy, thoracoscopy, lung puncture, and thoracic puncture drainage), the prognosis of 24 cases (92.3%) became satisfactory, and 2 (7.7%) died. Conclusion: Pulmonary infection caused by SAG is mainly seen in male patients with underlying diseases. No specificity is displayed in clinical manifestations. CT manifestations usually show intrapulmonary nodules, patchy shadows, consolidation and pleural effusion.