Comparative analysis of streptococcal toxic shock syndrome caused by three β-hemolytic streptococcal species in Japan.

OBJECTIVES

We aimed to compare the clinical features in patients with streptococcal toxic shock syndrome (STSS) caused by the three β-hemolytic streptococci (BHS): Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus dysgalactiae subsp. equisimilis (SDSE).

METHODS

Overall, 301 adult patients with STSS with S. pyogenes (32.9%), S. agalactiae (17.6%), and SDSE (49.5%) in Japan were enrolled between 2016 and 2021. Data were analyzed to identify differences in clinical characteristics among the three BHS. Bacterial isolates were examined for emm or capsular typing.

RESULTS

The incidence of STSS with S. pyogenes declined during the COVID-19 pandemic, but STSS with S. agalactiae and SDSE did not. Patients with SDSE were the oldest (median age, 81 years; interquartile range, 70-88 years) followed by those with S. agalactiae (76 years; 67-85 years) and S. pyogenes (66 years; 58-78 years). The case fatality rates (CFRs) of STSS caused by the three BHS were not significantly different, ranging from 48-59%; however, the CFR significantly increased with age in patients with SDSE (P <0.05).

CONCLUSIONS

The characteristics of STSS differed among the three BHS. Clinicians should be aware of poor outcomes in patients with STSS, and provide appropriate treatment at an early stage.