Characteristics of Streptococcal Toxic Shock Syndrome Caused by Different Beta-Hemolytic Streptococci Species: A Single-Center Retrospective Study

Background Streptococcal toxic shock syndrome (STSS) is a life-threatening condition caused by beta-hemolytic streptococci (BHS). Streptococcus pyogenes is the main causative agent of this disease; other BHS such as S. agalactiae or S. dysgalactiae could also cause STSS. However, the clinical characteristics of STSS caused by other types of BHS remain poorly understood. In this study, we evaluated the likelihood of STSS development in various streptococcal species. Methods We conducted a retrospective observational study using adult medical records of patients with invasive BHS in a tertiary care institution from 2002–2022 and classified them into STSS or non-STSS groups. Multivariable analysis of bacterial species adjusted for age and diabetes mellitus was conducted. S. pyogenes cases were propensity-matched (1:4) to non-pyogenes BHS cases. Results A total of 43 STSS and 285 non-STSS cases were identified. S. pyogenes, S. agalactiae, and S. dysgalactiae accounted for 17, 13, and 13 STSS cases, respectively. The crude mortality of STSS was approximately 35% in all groups. A multivariable analysis suggested that STSS was less frequent in S. agalactiae and S. dysgalactiae cases with odds ratio 0.24 (95% confident interval [CI]: 0.10–0.54, p<0.001) and 0.23 (95% CI: 0.10–0.55, p<0.001), respectively. Propensity score matching showed that S. pyogenes caused STSS more frequently than other BHS cases with an odds ratio of 3.28 (95% CI: 1.21–8.77, p=0.010). Conclusions This study described and compared the clinical characteristics of STSS caused by different BHS. We demonstrated that S. pyogenes caused STSS more often than other BHS.