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

BACKGROUNDGroup A <i>Streptococcus</i> (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 <i>emm</i>1 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 <i>emm</i> typing and analysis of clinical data in iGAS surveillance and having international collaboration for effective response to future surges.