Increase in invasive group A streptococcal disease among Australian children coinciding with northern hemisphere surges

Yara-Natalie Abo; Jane Oliver; Alissa McMinn; Joshua Osowicki; Ciara Baker; Julia E Clark; Christopher C Blyth; Joshua R Francis; Jeremy Carr; Pierre R Smeesters; Nigel W Crawford; Andrew C Steer

doi:10.1016/j.lanwpc.2023.100873

Increase in invasive group A streptococcal disease among Australian children coinciding with northern hemisphere surges

Lancet Reg Health West Pac. 2023 Aug 22:41:100873. doi: 10.1016/j.lanwpc.2023.100873. eCollection 2023 Dec.

Authors

Yara-Natalie Abo^{1

2

3

4}, Jane Oliver^{1

5}, Alissa McMinn¹, Joshua Osowicki^{1

2

4}, Ciara Baker¹, Julia E Clark⁶, Christopher C Blyth⁷, Joshua R Francis^{8

9}, Jeremy Carr^{10

11

12}, Pierre R Smeesters^{13

14}, Nigel W Crawford¹, Andrew C Steer^{1

2

4}

Affiliations

¹ Murdoch Children's Research Institute, Melbourne, Victoria, Australia.
² Infectious Diseases Unit, Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia.
³ Department of Microbiology, Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia.
⁴ Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
⁵ Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Victoria, Australia.
⁶ Queensland Children's Hospital, Queensland and School of Clinical Medicine, University of Queensland, Australia.
⁷ Telethon Kids Institute, University of Western Australia and Perth Children's Hospital, Western Australia, Australia.
⁸ Royal Darwin Hospital, Northern Territory, Australia.
⁹ Menzies School of Health Research, Charles Darwin University, Northern Territory, Australia.
¹⁰ Infection & Immunity, Monash Children's Hospital, Melbourne, Victoria, Australia.
¹¹ Monash University, Melbourne, Victoria, Australia.
¹² Department of Paediatrics, University of Oxford, Oxford, UK.
¹³ Department of Paediatrics, Brussels University Hospital, Academic Children Hospital Queen Fabiola, Université libre de Bruxelles, 1020 Brussels, Belgium.
¹⁴ Molecular Bacteriology Laboratory, Université Libre de Bruxelles, 1070 Brussels, Belgium.

Abstract

Background: Increases in invasive group A streptococcal disease (iGAS) have recently been reported in multiple countries in the northern hemisphere, occurring during, and outside of, typical spring peaks. We report the epidemiology of iGAS among children in Australia from 1 July 2018 to 31 December 2022.

Methods: The Paediatric Active Enhanced Disease Surveillance (PAEDS) Network prospectively collected iGAS patient notifications for children and young people aged less than 18 years admitted to five major Australian paediatric hospitals in Victoria, Queensland, Western Australia and the Northern Territory. Patients were eligible for inclusion if they had GAS isolated from a normally sterile body site, or met clinical criteria for streptococcal toxic shock syndrome or necrotising fasciitis with GAS isolated from a non-sterile site. We report patients' clinical and demographic characteristics, and estimate minimum incidence rates.

Findings: We identified 280 paediatric iGAS patients, median age 4.5 years (interquartile range 1.4-6.4). We observed a pre-pandemic peak annualised incidence of 3.7 per 100,000 (95% CI 3.1-4.4) in the 3rd quarter of 2018, followed by a decline to less than 1.0 per 100,000 per quarter from 2020 to mid-2021. The annualised incidence increased sharply from mid-2022, peaking at 5.2 per 100,000 (95% CI 4.4-6.0) in the 3rd quarter and persisting into the 4th quarter (4.9 per 100,000, 95% CI 4.2-5.7). There were 3 attributable deaths and 84 (32%) patients had severe disease (overall case fatality rate 1%, 95% CI 0.2-3.3). Respiratory virus co-infection, positive in 57 of 119 patients tested, was associated with severe disease (RR 1.9, 95% CI 1.2-3.0). The most common emm-type was emm-1 (60 of 163 isolates that underwent emm-typing, 37%), followed by emm-12 (18%).

Interpretation: Australia experienced an increase in the incidence of iGAS among children and young people in 2022 compared to pandemic years 2020-2021. This is similar to northern hemisphere observations, despite differences in seasons and circulating respiratory viruses. Outbreaks of iGAS continue to occur widely. This emphasises the unmet need for a vaccine to prevent significant morbidity associated with iGAS disease.

Funding: Murdoch Children's Research Institute funded open access publishing of this manuscript.

Keywords: Bacteraemia; Epidemiology; Invasive group A streptococcus; Sepsis; Streptococcus pyogenes; Viruses.