Background
The global health burden of Streptococcus pyogenes (Group A Streptococcus, GAS) disease has led the World Health Organization to declare GAS vaccine development an international priority. Severe acute GAS disease comprises hospitalised infections, toxin-mediated disease (scarlet fever and streptococcal toxic shock syndrome) and immune-mediated disease (acute rheumatic fever [ARF] and acute post-streptococcal glomerulonephritis). This study aimed to characterise the burden and spectrum of severe acute GAS disease in Auckland, New Zealand, to inform future GAS vaccine studies in this setting.
Methods
This population-based, multicentre prospective observational study utilised laboratory data and ARF notifications to capture all hospitalised GAS infections and toxin- and immune-mediated disease cases associated with hospitalisation in Auckland during 2023. The epidemiology, clinical features, incidence and hospitalisation costs of these cases are described.
Results
The complete clinical spectrum of severe acute GAS disease was observed, with 606 cases captured corresponding to 1:2000 people affected annually (52 cases/100,000 population/year). The burden is inequitably distributed across the population, greatest at the intersection of age, ethnicity and socioeconomic deprivation. In the most deprived areas, approximately 1:400 Pacific children <10-years and 1:200 Pacific adults ≥80-years are affected annually (261 and 483 cases/100,000 population/year, respectively). Hospitalisation costs exceeded $13.2 million New Zealand dollars.
Conclusion
This study demonstrates that the complete clinical spectrum of severe acute GAS disease occurs in Auckland and is associated with a substantial health and economic burden. The high incidence and entire range of severe acute GAS disease present make Auckland an ideal location for future vaccine studies.