Aim: To assess the impact of COVID-19 on the incidence and molecular epidemiology of invasive infections caused by Streptococcus pneumoniae (IPD) and Streptococcus pyogenes (iGAS) in the Czech Republic (CR).
Methods: Epidemiological data on IPD and iGAS from 2018 to 2024 were analyzed. WGS was conducted on selected isolates at the National Reference Laboratory for Streptococcal Infections (NRL/STR) to investigate prevailing GPSC, MLST in S.pneumoniae strains, and the presence of the M1UK sublineage among S.pyogenes strains.
Results: A 47% decrease in IPD morbidity was observed between 2018–2019 and 2020–2021, followed by a 129% increase between 2020–2021 and 2023–2024. In comparison to 2018–2019, IPD morbidity in 2023–2024 increased by 22%. Post-pandemic data revealed an increase in certain S. pneumoniae serotypes compared to the pre-pandemic period, serotypes 3, 4, 14, and 19F has increased in prevalence despite being included in the 10-valent, and 13-valent vaccines. Comparison of WGS data from isolates collected during the pre-pandemic, pandemic, and post-pandemic periods revealed no changes in the trends of occurring GPSCs or STs.
Relative to the 2018–2019 period, the iGAS morbidity in 2023–2024 increased by 348%. The emm1 type became dominant emm type, comprising 38% of all S. pyogenes isolates analyzed in NRL/STR in 2023. WGS identified the M1UK sublineage in 31 out of 36 tested emm1 isolates from 2022-2023.
Conclusion: The post-pandemic period has seen the resurgence of IPD, but without the change in circulating GPSCs and STs, and the emergence of S. pyogenes emm1, particularly the M1UK sublineage.
Grant No. 101113387 - HERA2CZ.