Multi-country surveillance of paediatric invasive group A Streptococcus infection, European Union/European Economic Area countries, 2022/23 season.

BACKGROUNDGroup A Streptococcus (GAS) commonly causes mild bacterial infections but also deadly invasive disease. An upsurge in paediatric invasive GAS (iGAS) infections was observed during the last quarter of 2022 in the European Union/European Economic Area (EU/EEA) countries.AIMWe aimed to assess iGAS surveillance in the EU/EEA countries and investigate the epidemiology of iGAS infections during the 2022/23 season.METHODSWe conducted a study on GAS and iGAS surveillance to evaluate coverage and surveillance methodology across the EU/EEA countries. We collected and analysed data on paediatric iGAS cases (patients aged ≤ 16 years) occurring in September 2022-June 2023 that resulted in hospitalisation or death. Associations of severe outcome (admission to intensive care unit and/or death) with potential risk factors were estimated by logistic regression in a case-case analysis.RESULTSNineteen countries responded to the questionnaire; eleven had mandated national surveillance for iGAS before 2022. Eight countries submitted data on 1,277 paediatric iGAS cases involving hospitalisation or death: 56% were males and median age was 4 years. Sixty-three (5%) of these cases died. Severe outcome was associated with emm1 type (odds ratio (OR) = 1.73; 95% confidence interval (CI): 1.13-2.67), having a sepsis without a known anatomic source (OR = 1.73; 95% CI: 1.11-2.73) and lower respiratory tract infections (OR = 4.14; 95% CI: 2.70-6.44).CONCLUSIONSurveillance of GAS and iGAS infections varied among the participating countries. We highlight the importance of including emm typing and analysis of clinical data in iGAS surveillance and having international collaboration for effective response to future surges.