Purpose: Studies have shown increased invasive Group A Streptococcus (GAS) disease, including bloodstream infections (GAS-BSI). However, the epidemiological data of GAS-BSI are limited in children.We aimed to describe GAS-BSI in Spanish children over 13 years (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017).Methods: Multicenter retrospective cohort study from 16 Spanish hospitals. Epidemiology, symptomatology, laboratory, treatment, and outcome of GAS-BSI in children ≤16 years were analyzed.Results: 109 cases of GAS-SBI were included, with incidence rate of 4.3 episodes/100,000 children attended at the emergency department/year. We compared incidence between two periods (P1:2005-June 2011 vs P2:July 2011-2017) and observed a non-signi cant increase along the study period (APC:+6.0% [95%CI:-2.7,+15.4]; p=0.163).Median age was 24.1 months (IQR:14.0-53.7), peaking during the rst four years of life (89/109 cases;81.6%). Primary BSI (46.8%), skin and soft tissue (21.1%), and osteoarticular infections (18.3%) were the most common syndromes. We compared children with primary BSI with those with a known source and observed that the former had shorter hospital stay (7vs.13 days; p=0.003) and received intravenous antibiotics less frequently (72.5%vs.94.8%; p=0.001) and for shorter periods (10vs.21 days; p=0.001). 22% of cases required PICU admission. Factors associated with severity were respiratory distress, pneumonia, thrombocytopenia, and surgery, but in multivariate analysis, only respiratory distress remained signi cant ). Two children (1.8%) died. Conclusion:We observed a trend in increased incidence of GAS-BSI within the study period. Younger children were more frequently involved, and primary BSI was the most common and less severe syndrome. PICU admission was frequent, being respiratory distress the main risk factor.

Purpose: Studies have shown increased invasive Group A Streptococcus (GAS) disease, including bloodstream infections (GAS-BSI). However, the epidemiological data of GAS-BSI are limited in children. We aimed to describe GAS-BSI in Spanish children over 13 years (2005-2017). Methods: Multicenter retrospective cohort study from 16 Spanish hospitals. Epidemiology, symptomatology, laboratory, treatment, and outcome of GAS-BSI in children ≤16 years were analyzed. Results: 109 cases of GAS-SBI were included, with incidence rate of 4.3 episodes/100,000 children attended at the emergency department/year. We compared incidence between two periods (P1:2005-June 2011 vs P2:July 2011-2017) and observed a non-significant increase along the study period (APC:+6.0% [95%CI:-2.7,+15.4]; p=0.163). Median age was 24.1 months (IQR:14.0–53.7), peaking during the first four years of life (89/109 cases;81.6%). Primary BSI (46.8%), skin and soft tissue (21.1%), and osteoarticular infections (18.3%) were the most common syndromes. We compared children with primary BSI with those with a known source and observed that the former had shorter hospital stay (7vs.13 days; p=0.003) and received intravenous antibiotics less frequently (72.5%vs.94.8%; p=0.001) and for shorter periods (10vs.21 days; p=0.001). 22% of cases required PICU admission. Factors associated with severity were respiratory distress, pneumonia, thrombocytopenia, and surgery, but in multivariate analysis, only respiratory distress remained significant (adjusted OR:9.23 [95%CI:2.16-29.41]). Two children (1.8%) died. Conclusion: We observed a trend in increased incidence of GAS-BSI within the study period. Younger children were more frequently involved, and primary BSI was the most common and less severe syndrome. PICU admission was frequent, being respiratory distress the main risk factor.