Abstract: Objective To investigate the survival status and pathogens in adult patients with severe communityacquired pneumonia (SCAP) for the past ten years in our hospital. Methods A total of 159 adult patients with SCAP were enrolled for this study from January 2007 to December 2016 in our hospital. Patients were divided into early stage group (from January 2007 to December 2011, n=71) and late stage group (from January 2012 to December 2016, n=88). The clinical data, pathogen distribution and prognosis were compared between two groups. Results (1) The proportion of patients with blood urea nitrogen (BUN) > 7.1 mmol/L was significantly higher in late stage group than that of early stage group (P＜0.05). There were no significant differences in baseline data, vital signs, imaging findings and other laboratory examinations between the two groups (P＞0.05). (2) For distribution of pathogens, 42 and 49 cases were detected pathogens in early stage group and late stage group. The detection rate of Legionella pneumophila was significantly higher in late stage group than that in early stage group (26.5% vs. 7.1%, P＜0.05). (3) For complications, the incidence of septic shock was significantly higher in late stage group than that in the early stage group (22.7% vs. 9.9%, P＜0.05). The fatality rate within 30 d after admission was significantly higher in late stage group than that of early stage group (43.2% vs. 25.4%, P < 0.05). Results of multi-factor Cox proportional hazard regression analysis showed that septic shock and respiratory acidosis were independent risk factors of mortality in early stage group (P＜0.05) while septic shock, chronic obstructive pulmonary disease (COPD) and multi- lobar infiltrates were independent risk factors of mortality in late stage group (P＜0.05). Conclusion In the past ten years, basic clinical characteristics of adult patients with SCAP in our hospital have changed little, but detection rate of legionella has showed increasing trend, and the short-term mortality rate has increased. Whether or not patients are combined with septic shock is a key factor affecting the prognosis.

Key words: pneumonia, community- acquired infections, legionella, prognosis, community- acquired pneumonia, pathogen, septic shock