Prevalence of Group A β-hemolytic Streptococcal Throat Carriage and Prospective Pilot Surveillance of Streptococcal Sore Throat in Ugandan School Children

Abstract Objectives Group A β-hemolytic streptococcus (GAS), also known as Streptococcus pyogenes, is responsible for an annual 600 million cases of acute pharyngitis globally, with 92% of those infections occurring in low-resource settings. Further knowledge of the acute streptococcal pharyngitis burden in low resource settings is essential if serious post-streptococcal complications, rheumatic fever (RF) and its long-term sequel rheumatic heart disease (RHD), are to be prevented. Methods We conducted two studies in school-aged children (5 – 16 years): a cross-sectional study of streptococcal pharyngeal carriage followed by a prospective cohort study of streptococcal sore throat over 4 weeks from March to April 2017. Results The cross-sectional study revealed an overall prevalence of GAS carriage was 15.9% (79/496, 95% CI 12.8-19.5%). Among 532 children enrolled in the prospective cohort study, 358 children (67%) reported 528 sore throats, with 221 (41.1%) experienced at least one GAS positive sore throat. The overall GAS positive rate for sore throat was 41.8% (221/528). Conclusions The GAS pharyngeal carriage rates seen in Uganda (15.93%, 95% CI 12.8-19.5%) are higher than the most recent pooled results globally, 12% (range 6-28%). Additionally, pilot data suggest a substantially higher percentage of sore throat that was GAS positive (41.8%) compared to pooled global rates when active recruitment is employed.