Background: Asymptomatic children can be a major reservoir of pharyngeal Group A Streptococcus (GAS). There is a need to document GAS carriage, so as to inform the development of putative GAS vaccines. We, therefore, undertook to perform a cross-sectional study to determine the prevalence of GAS carriage in school children in Cape Town; we considered our results in the context of a meta-analysis of pooled data of GAS carriage in school children residing in African countries.
Methods: Pharyngeal swabs were obtained from learners in Cape Town and processed at the microbiology facility at Groote Schuur Hospital. Thereafter, we conducted a systematic review through a comprehensive literature search among several sources. Prevalence estimates with 95% CIs were determined using a random-effects meta-analysis.
Results: GAS was isolated from 31/950 healthy learners (3%; 95%CI, 2%-4 %) enrolled from 2009-2011. Together with 18 studies meeting our systematic review inclusion criteria, the pooled prevalence was 9% (95% CI, 6% to 11%; 19 studies). Sub-analyses revealed similar pooled rates across Southern, Eastern and Northern Africa. Countries within Central Africa and West Africa had notably lower estimates of <8%.
Discussion: Our cross-sectional study reports a low prevalence of GAS carriage in South African school children. Across Africa, pooled results reveal a GAS carriage estimate of 9%, lower than the 12% reported in an earlier systematic review. Given that, studies of pharyngitis report GAS prevalence of >20%, our findings emphasize the association between GAS and pharyngitis.