National 10-year Cohort Study of Life-threatening Invasive Group A Streptococcal Infection in Children, 2013-2023.

BACKGROUND

Invasive group A streptococcal disease (iGAS) is an important cause of pediatric morbidity and mortality. We aimed to describe severe, life-threatening, iGAS cases to inform critical care services planning and identify potential opportunities for early intervention to prevent progression to death.

METHODS

Retrospective, multicenter, national cohort study in Scotland investigating critically unwell iGAS cases ≤15 years old from October 01, 2013 to September 30, 2023. We included children and young people (CYP) who required advanced intensive care or died with iGAS as the primary cause of death. Information collected included demographics, Streptococcus pyogenes emm types, viral coinfections and clinical outcomes.

RESULTS

Eighty-two cases of severe, life-threatening iGAS were identified, with 20 resulting in death. The annual iGAS pediatric intensive care unit (PICU) admission rate was 0.69/100,000 CYP, with a mean annual mortality rate of 0.22/100,000. iGAS PICU admissions dropped during 2020-2021, returned to baseline in 2021-2022, and then increased sharply in 2022-2023 without an increase in death rates. Across the cohort, the predominant emm type was type 1. In 9.8% of cases, GAS was identified using a nonculture molecular method (specific polymerase chain reaction or 16S rRNA sequencing). Prior primary or secondary care contact was sought by 9/20 (45%) of CYP who died; there was no significant association between time-to-care to PICU and illness severity or risk of death. Viral coinfections were common and associated with higher severity scores.

CONCLUSION

We demonstrate a significant annual burden of severe, life-threatening iGAS at the national level. High rates of viral coinfections and care-seeking before PICU admission or death, suggest potential opportunities for intervention.