Poster Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

High rates of group A streptococcal pharyngitis among a longitudinal cohort of school-aged children in remote Western Australia (#3)

Janessa Pickering 1 , Dylan D Barth 1 , Bernadette Wong 1 , Elizabeth McKinnon 2 , Marianne Mullane 2 , Alexandra Whelan 2 , August Mikucki 1 , Rebecca Dalton 1 , Andrew Hayes 3 , Mark Davies 3 , Alana Whitcombe 4 5 , Nicole J Moreland 4 5 , Scott Winslow 1 , John Jacky 2 , Liam Bedford 2 , Slade Sibosado 2 6 , Robyn Macarthur 7 , Shelley Kneebone 7 , Narelle Ozies 7 , Delia Lawford 8 , Jonathan Carapetis 2 , Asha C Bowen 1 , on behalf of the Missign Piece Surveillance Team 2
  1. Wesfarmers Centre for Vaccine and Infectious Diseases, The Kids Research Institute Australia, Perth, Western Australia, Australia
  2. The Kids Research Institute Australia, Perth, Western Australia, Australia
  3. Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
  4. The Maurice Wilkins Centre for Molecular Biodiscovery, The University if Auckland, Auckland, New Zealand
  5. School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
  6. Kimberley Aboriginal Health Alliance, Broome, Western Australia, Australia
  7. Derby Aboriginal Health Service, Derby, Western Australia, Australia
  8. Broome Regional Aboriginal Medical Service, Broome, Western Australia, Australia

Background

The prevalence of concurrent superficial group A Streptococcal (GAS) infections impetigo and pharyngitis is poorly understood yet guidelines recommend the early diagnosis of both infections to prevent acute rheumatic fever (ARF). Surveillance to enable the concurrent detection of these infections in high-risk populations has rarely been performed but is necessary to inform superficial GAS and ARF prevention.

Methods

In the ‘Missing Piece’ observational cohort study, children attending one of two schools in the remote Kimberley region of Western Australia were assessed for signs and symptoms of impetigo and pharyngitis at repeated screening visits (conducted up to three times per year). In addition, weekly assessments were performed to assess children with self-reported symptoms. GAS isolated from throat and skin swabs were whole genome sequenced and antibodies against streptococcal antigens were detected in dried blood spots.

Results

Two-hundred and fifty-four children participated in school surveillance from 2019-2022. A higher-than-anticipated rate of GAS-positive pharyngitis was detected, however GAS-positive impetigo was lower compared with other studies in the Kimberley. GAS strains cultured from skin and throat swabs were diverse but did not differ significantly according to source or participant ethnicity. Aboriginal children experienced more infections than did children of other ethnicities, particularly infections that were GAS culture-positive.

Conclusion

The high rates of GAS infection observed in school-aged children are of concern and must be addressed in the Kimberley region of Western Australia and in all populations at high risk of ARF and rheumatic heart disease.