Background
The incidence of invasive disease caused by group A Streptococcus (GAS) has increased in multiple countries. To inform interventions such as GAS vaccines, we estimated incidence of invasive GAS (iGAS) disease, including death and disability outcomes, among high risk groups—pregnant women and children under 5 years. These represent, to the best of our knowledge, the first available estimates globally.
Methods
Systematic review and meta-analyses on iGAS outcomes (incidence, case fatality, and neurodevelopmental impairment) in pregnancy and children worldwide. We included published data from 1/1/2000 and unpublished data from an investigator group formed from collaborators worldwide.
Results
We identified 950 published and 29 unpublished datasets. 20 studies (seven unpublished) from 12 countries provided sufficient data to be included in meta-analyses. We did not identify studies reporting iGAS incidence during pregnancy, or on neurodevelopmental impairment in LMICs. Worldwide iGAS incidence was, 0·12/1000 live births (95%CI 0·11-0·14) in pregnancy/post-postpartum; 0·04/1000 live births (0·03-0·05) for neonates; 0·13/1000 live births (0·10-0·16) for infants; and, 0·09/1000 person-years ( 0·07-0·10) for children (0-5years). Incidence was higher in LMICs, particularly in neonates (0·12/1000 live births; 0·00-0·24) compared to (0·02/1000 live births; 0·00-0.03) in HICs. Case fatality risks were high, particularly among neonates in LMICs (61%; 33-89%).
Conclusions
We found high disease incidence and case fatality among young children with iGAS, particularly in LMICs. Notably, for LMICs, limited data are available for children, and no data are available for pregnant women. Incidences are likely underestimates, particularly in LMICs, due to limited GAS surveillance. Improving available data is essential to inform GAS vaccine development and evaluation.