Poster Presentation 20th Lancefield International Symposium on Streptococci and Streptococcal Diseases 2017

Group A Streptococcus pharyngitis and pharyngeal carriage: A systematic review (#214)

Jane R Oliver 1 , Erandi Malliya Wadu 1 , Nicole J Moreland 2 , Nevil Pierse 1 , Deborah A Williamson 3 , Michael G Baker 1
  1. University of Otago Wellington, Newtown/Wellington, WELLINGTON, New Zealand
  2. Maurice Wilkins Centre and School of Medical Sciences,, University of Auckland, Auckland, New Zealand
  3. Department of Microbiology and Immunology, Peter Doherty Institute, University of Melbourne , Melbourne, Australia

Antibiotic treatment of Group A Streptococcus (GAS) pharyngitis is important in acute rheumatic fever (ARF) prevention, however clinical guidelines for prescription vary. A proportion of patients with GAS culture-positive pharyngitis are GAS carriers with acute viral infections. These patients may receive antibiotics unnecessarily. This review aimed to assess the prevalence of GAS pharyngitis and carriage in different settings.

A systematic literature review and meta-analysis were performed using Medline and EMBASE databases. Pooled prevalence estimates for GAS culture-positive pharyngitis, serologically-confirmed (‘true’) GAS pharyngitis and asymptomatic pharyngeal carriage were generated. Findings were stratified by age group, recruitment method and country income level.

284 eligible studies were identified. The prevalence of GAS culture-positive pharyngitis was 24.1% (95% CI: 22.6-25.6%) in clinical settings, but significantly less in active sore throat management programmes 10.0% (8.1-12.4%). The prevalence of serologically-confirmed GAS pharyngitis was 10.3% (6.6-15.7%) in children from OECD countries and their asymptomatic GAS carriage prevalence was 10.5% (8.4-12.9%). GAS culture-positive pharyngitis was more prevalent in OECD countries (24.3%, 22.6-26.1%) than non-OECD countries 17.6% (14.9-20.7%).

These findings have important implications for clinical sore throat management and ARF prevention. In clinical settings, approximately 10% of children with throat swabs have true GAS pharyngitis, but this increases to around 55% when the child is GAS culture-positive. In active sore throat management programmes, the prevalence of GAS detection is lower, and if it declines towards the asymptomatic carriage rate, there may be little benefit from