Predictors of Mortality of Streptococcal Bacteremia and the Role of Infectious Diseases Consultation: A Retrospective Cohort Study

Abstract Background Streptococcal bacteremia is associated with high mortality. Thia study aims to identify predictors of mortality among patients with streptococcal bacteremia. Methods This retrospective study was conducted at the Lausanne University Hospital, Switzerland, and included episodes of streptococcal bacteremia among adult patients from 2015 to 2023. Results During the study period, 861 episodes of streptococcal bacteremia were included. The majority of episodes were categorized in the Mitis group (348 episodes; 40%), followed by the Pyogenic group (215; 25%). Endocarditis was the most common source of bacteremia (164; 19%). The overall 14-day mortality rate was 8% (65 episodes). The results from the Cox multivariable regression model showed that a Charlson comorbidity index >4 (P .001; hazard ratio [HR], 2.87; confidence interval [CI]: 1.58–5.22), Streptococcus pyogenes (P = .011; HR, 2.54;CI: 1.24–5.21), sepsis (P < .001; HR, 7.48; CI: 3.86–14.47), lower respiratory tract infection (P = .002; HR, 2.62; CI: 1.42–4.81), and absence of source control interventions within 48 hours despite being warranted (P = .002; HR, 2.62; CI: 1.43–4.80) were associated with 14-day mortality. Conversely, interventions performed within 48 hours of bacteremia onset, such as infectious diseases consultation (P < .001; HR, 0.29; CI: .17–.48) and appropriate antimicrobial treatment (P < .001; HR, .28; CI: .14–.57), were associated with improved outcome. Conclusions Our findings underscore the pivotal role of infectious diseases consultation in guiding antimicrobial treatment and recommending source control interventions for patients with streptococcal bacteremia. The overall 14-day mortality rate among 861 episodes of streptococcal bacteremia was 8%. Interventions performed within 48 hours of bacteremia onset, such as infectious diseases consultation, appropriate antimicrobial treatment, and source control were associated with improved outcome.