Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2025 Feb;44(2):383-391.
doi: 10.1007/s10096-024-05015-2. Epub 2024 Dec 16.

Trends in the growing impact of group A Streptococcus infection on public health after COVID-19 pandemic: a multicentral observational study in Okayama, Japan

Shinnosuke Fukushima  1   2   3 , Takashi Saito  4 , Yoshitaka Iwamoto  4 , Yuko Takehara  5 , Haruto Yamada  6 , Koji Fujita  7 , Masayo Yoshida  8 , Yasuhiro Nakano  1 , Hideharu Hagiya  9
Affiliations
Observational Study

Trends in the growing impact of group A Streptococcus infection on public health after COVID-19 pandemic: a multicentral observational study in Okayama, Japan

Shinnosuke Fukushima et al. Eur J Clin Microbiol Infect Dis. 2025 Feb.

Abstract

Purpose: Following the COVID-19 pandemic, group A Streptococcus (GAS) infection has been surging worldwide. We aimed to compare the disease burden between notified cases of streptococcal toxic shock syndrome (STSS) and unreported GAS infections.

Methods: This is a multicentral observational study, retrospectively performed at seven hospitals in Okayama prefecture in Japan from January 2022, to June 2024. Clinical and microbiological data of patients with positive cultures of GAS were collected from the medical records. Primary outcomes were defined as rates of surgical procedures, intensive care unit (ICU) admission, and in-hospital mortality, which were compared among patients with locally-defined STSS, invasive GAS (iGAS), and non-iGAS infection.

Results: GAS was detected in 181 patients, with 154 active cases of GAS infection. The number of patients with GAS infection surged in late 2023. The most common source of infection was skin and soft tissue infections, accounting for 83 cases, including 15 cases of necrotizing fasciitis, and 12 cases (7.8%) were notified to public health authorities as STSS. Among the 25 unreported iGAS cases, 9 (36.0%) underwent surgical intervention, and 4 patients (16.0%) required ICU admission. The mortality rates in the unreported iGAS cases were comparable to those observed in the notified STSS.

Conclusions: We highlighted that the number of iGAS infections was twofold higher than that of notified STSS, with comparable mortality rate between these groups, indicating substantial underestimation of the true burden of iGAS. This epidemiological investigation has significant implications for enhancing infectious disease surveillance frameworks and public health policy development.

Keywords: Epidemiology; Group A Streptococcus; Necrotizing fasciitis; Streptococcal toxic shock syndrome; Surveillance.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethical approval: Ethical approval was obtained from the Institutional Review Board of Okayama University Hospital (No. 2406-015). Consent for publication: The requirement for informed consent was waived because this was a retrospective analysis of routinely collected anonymized data. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Study enrolment flow. GAS: group A streptococcus, iGAS: invasive GAS, STSS: streptococcal toxic shock syndrome. Of the 154 GAS infection cases, 12 cases (7.8%) were notified as STSS cases, whereas the remaining 142 cases (92.2%) did not meet the diagnostic criteria for STSS. Among the unreported cases, invasive cases are 25, 117 are non-invasive cases
Fig. 2
Fig. 2
Number of patients diagnosed with GAS infection, (A) by six-month intervals and (B) by patient age. GAS: group A streptococcus, iGAS: invasive GAS, SSTI: skin and soft tissue infection. Other infections include pharyngitis, respiratory and ear infections, abdominal and pelvic infections, genital infections, parotitis, conjunctivitis, primary bacteremia, and streptococcal toxic shock syndrome
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Defining the group A streptococcal toxic shock syndrome (1993) Rationale and consensus definition. The Working Group on severe streptococcal infections. JAMA. American Medical Association (AMA) 390–391 - PubMed
    1. Steer AC, Lamagni T, Curtis N, Carapetis JR (2012) Invasive group a streptococcal disease: epidemiology, pathogenesis and management: epidemiology, pathogenesis and management. Drugs 72:1213–1227 - PMC - PubMed
    1. Inada M, Iwamoto N, Nomoto H, Tsuzuki S, Takemoto N, Fuwa N et al (2024) Characteristics of streptococcal toxic shock syndrome caused by different beta-hemolytic streptococci species: a single-center retrospective study. Open Forum Infect Dis 11:ofae486 - PMC - PubMed
    1. Centers for Disease Control and Prevention Active Bacterial Core surveillance (ABCs) 2024 [Internet]. [cited 2024 Oct 1]. https://www.cdc.gov/abcs/index.html
    1. Miller KM, Lamagni T, Cherian T, Cannon JW, Parks T, Adegbola RA et al (2022) Standardization of epidemiological surveillance of invasive group a streptococcal infections. Open Forum Infect Dis 9:S31–40 - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources