Pneumococcal pneumonia presenting with septic shock: characteristics, outcomes, serotypes and genotypes

Abstract number: O130

Garcia-Vidal C., Ardanuy C., Tubau F., Viasus D., Liñares J., Gudiol F., Carratalà J.

Objectives: We aimed to ascertain the characteristics, outcomes, serotypes and genotypes of pneumococcal pneumonia (PP) presenting with septic shock.

Methods: Observational analysis of a prospective cohort of 1041 nonseverely immunosuppressed adults with PP requiring hospitalisation (1995–2008). Of them, 556 were diagnosed by urinary antigen and/or 650 were diagnosed by culture. Overall, 86% of pneumococcal strains were available for serotyping (Quellung) and 58% for PFGE (Smal) and or MLST. The diagnosis of septic shock was based on a systolic blood pressure <90 mmHg and peripheral hypoperfusion with clinical or bacteriologic evidence of uncontrolled infection.

Results: A total of 114 (11%) patients with PP had septic shock at presentation. Patients with shock were younger (61 vs 66 yrs; p = 0.003), were more frequently current smokers (45% vs 28%; p = 0.002), had received more commonly corticosteroid therapy (13% vs 6%; p = 0.015), and were more frequently classified into high-risk PSI classes (81% vs 60%; p < 0.001) than those who did not have this complication. They were also less likely to have received prior influenza vaccine (31% vs 48%; p = 0.007) and had more frequently bacteraemia (41% vs 30%; p = 0.014). No significant differences were found in rates of penicillin- (2% vs 2%) and erythromycin-resistance (16% vs 12%). Serotype 3 was more commonly associated with shock (40% vs 24%; p = 0.007), whereas serotype 1 was rarely associated with this complication (2% vs 9%; p = 0.041). No significant differences were found regarding genotypes: ST2603 (26% vs 16%), Netherlands-ser8-ST53 (10% vs 3%), Netherlands-ser3-ST180 (10% vs 8%), Spain-ser9V-ST156 (10% vs 12%). Patients with shock required more frequently mechanical ventilation (38% vs 4%; p < 0.001), and had longer LOS (19 vs 10 days; p < 0.001). Early (10% vs 1%; p < 0.001) and overall case-fatality rates (25% vs 5%; p < 0.001) were higher in patients with shock.

Conclusions: PP presenting with septic shock is still associated with a poor outcome. It occurs mainly in current smokers, patients receiving corticosteroids, and in those infections caused by serotype 3. Prior influenza vaccination and PP caused by serotype 1 are associated with a lower risk of shock.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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