# Group A Streptococcus Meningitis, United States, 1997–2022

## TL;DR

This study examines the incidence and severity of Group A Streptococcus meningitis in the US from 1997 to 2022, finding it to be rare but deadly compared to other meningitis causes.

## Contribution

The study provides the first comprehensive analysis of GAS meningitis incidence, case fatality rates, and antimicrobial resistance trends in the US.

## Key findings

- GAS meningitis had a case-fatality rate of 19.4%, higher than other common bacterial meningitis causes.
- Clindamycin resistance in GAS meningitis isolates increased significantly from 3.2% to 17.7% over the study period.
- Children under one year had the highest average annual incidence of GAS meningitis at 0.23 cases/100,000.

## Abstract

Group A Streptococcus (GAS) causes a variety of diseases in humans but is not widely appreciated as a cause of meningitis. During 1997–2022, ten sites participating in the Active Bacterial Core Surveillance network in the United States identified GAS meningitis cases. We calculated annual incidence and case-fatality rates (CFRs) for 320 of those cases and determined antimicrobial resistance by whole-genome sequencing. Annual incidence of GAS meningitis ranged from 0.02 to 0.07 cases/100,000 persons. Children <1 year of age had the highest average annual incidence, 0.23 cases/100,000 children. GAS meningitis had a higher CFR (19.4%) than meningitis caused by group B Streptococcus, Streptococcus pneumoniae, Neisseria meningitidis, or Haemophilus influenzae. Clindamycin resistance among GAS meningitis isolates increased from 3.2% during 1997–2002 to 17.7% during 2018–2022. Clinicians should be aware that meningitis is an uncommon but severe manifestation of invasive GAS and has a higher CFR than more established meningitis etiologies.