1989. Surge in Group A Streptococcal Infections in England during 2022

Abstract

Abstract Background Following removal of non-pharmaceutical interventions (NPI) to restrict SARS-CoV-2 transmission in England, large increases above seasonally expected levels of group A streptococcal (GAS) infections and associated deaths were seen, particularly in children, during 2022. Methods Nationwide data from UK Health Security Agency surveillance databases were extracted, including statutory clinical notifications of scarlet fever and laboratory-confirmed invasive GAS infections (iGAS; sterile-site specimens). Analyses compared infection and mortality rates in England for the pre-COVID-19 pandemic (2017-2019), pandemic-NPI (2020-2021), and post removal of COVID-19 NPI (post-NPI; 2022-2023) periods. Results Pre-pandemic, a mean of 2481 iGAS cases (range 2138-2921; 13%-14% < 15y; Figure) per-year were recorded in England (4.4/100,000 population; 95% confidence interval (CI):4.3-4.6). Case numbers fell markedly during the pandemic-NPI period, 1462 iGAS cases in 2020 (2.6/100,000; 7% aged < 15y) and 829 in 2021 (1.5/100,000; 6% < 15y; Figure). Post-NPI cessation, iGAS cases increased to 2892 (5.1/10,000; 24% < 15y) in 2022, remaining high into Jan-Mar 2023 (1361; 21% < 15y). Scarlet fever diagnoses similarly increased, with 54,630 (91.6/100,000; CI: 90.8-92.4) notified in 2022 (England & Wales), the highest number since 1953. In 2022, 339 deaths (< 7d iGAS diagnosis) were reported (case-fatality rate (CFR) 11.7%; CI:10.6-13.0%; 16% deaths were aged < 15y), compared to 214-335 per-year pre-pandemic (8%-10% in < 15y) and 88 in 2021 (6%< 15y). Respiratory virus co-infections were identified in 19% iGAS aged < 15y during 2022, CFR: 19.8%. Post-NPI cessation, strain typing identified increasing dominance of emm1 and emm12 (all ages: 35% and 18%) in 2022, compared with 3% and 2% in pandemic-NPI and 23% and 6% pre-pandemic (all-ages). Conclusion iGAS presentations showed a marked rebound in 2022, most notably in children, with re-emergence of emm1. The rapid, steep increase in morbidity was possibly driven by increased opportunities for exposure and sub-optimal immunity following COVID-19 NPI. Disclosures All Authors: No reported disclosures