Prevalence and Factors Associated With Group a Streptococcal Pharyngeal Carriage Among Primary School Children in Bomet County

Abstract

Background: Asymptomatic streptococcal pharyngeal carriers act as reservoirs for invasive Group A Streptococcus (GAS) clones, are important drivers for GAS transmission and are predisposed to acute rheumatic fever/rheumatic heart disease on acquisition of new rheumatogenic clones. Bomet County is considered to be within the ‘rheumatogenic’ belt but local studies around GAS are lacking despite the high burden of streptococcal complications. There is limited utilization of point of care rapid antigen detection tests (RADTs) which facilitate quick diagnosis and treatment of GAS pharyngitis. Objectives: The aim of this study was to determine the prevalence of and factors associated with GAS pharyngeal carriage among primary school children in Bomet County, Kenya. Methods: A cross-sectional study targeting children age 5-15 years in primary schools from Bomet County was conducted between December 2020 to March 2021. A semi-structured questionnaire was used to collect data including school characteristics, socio-demographics, and clinical features. For every enrolled child, a throat swab was taken and subjected to the RADT and the results recorded. Those who tested positive were categorized as GAS pharyngeal carriers. Analysis was done using the IBM SPSS v.24 with prevalence of GAS pharyngeal carriage being presented as a percentage with a 95% confidence interval (CI). Associated risk factors were analysed using Chi-square tests and Fischer’s exact with statistical significance set at p <0.05. Results: Out of the 210 children screened, twenty tested positive for GAS pharyngeal carriage giving a prevalence of 9.5% (95% CI= 6.3-14.3), with most carriers attending overcrowded classrooms. However, none of the factors examined were statistically significant. Conclusion and recommendations: The prevalence of GAS pharyngeal carriage among children aged 5-15 years old attending primary schools in Bomet county was 9.5%. Notably, overcrowded classrooms recorded higher carrier rates. We recommend improving care seeking practices for sore throats in this age group, utilizing a rapid test for point of care diagnosis of GAS and maintaining a maximum occupancy of not more than 0.9pupils/m2 of classroom area as stipulated in the Safety Standards Manual for schools in Kenya.