Predictors of mortality of streptococcal bacteremia and the role of infectious diseases consultation; a retrospective cohort study.

BACKGROUND: Streptococcal bacteremia is associated with high mortality. The 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 0.001; HR 2.87, CI 1.58-5.22), S. pyogenes (P 0.011; HR 2.54, CI 1.24-5.21), sepsis (P < 0.001; HR 7.48, CI 3.86-14.47), lower respiratory tract infection (P 0.002; HR 2.62, CI 1.42-4.81), and absence of source control interventions within 48 hours despite being warranted (P 0.002; 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 < 0.001; HR 0.29, CI 0.17-0.48), and appropriate antimicrobial treatment (P < 0.001; HR 0.28, CI 0.14-0.57) 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.