Beta hemolytic streptococci pharyngeal carriage in preschool children in pleven (Bulgaria)

Abstract

A prospective study was conducted to investigate the throat carrier rate of beta hemolytic streptococci (BHS) and to serotype the group A streptococci (GAS) in asymptomatic preschool children in Pleven (Bulgaria). Throat swabs were collected from 74 healthy children aged 3 to 7 years (mean: 4.72 ± 1.28 years). The Lancefield group of the streptococci isolated in pure culture was determined using the latex agglutination test (Slidex Strepto-Kit, BioMerieux, France). The strains of GAS were serotyped with anti-T, -SOF and -M sera. BHS were isolated from 24.02% of asymptomatic children, ranging from 20% to 26.42% at different stages of the study. GAS represented 16.20% of all tested, group C streptococci were isolated in 6.70%, group G in 1.12% of those surveyed. Circulation was found in four M serotypes (M 11, M 12, M 14 and M 49), a leading M 14 (65.52%) and two T serotypes (T 11 and T 14), the dominant T 14 (82.76%). The results of our study highlight the importance of regular surveillance programmes to keep GAS infections and carriage in check.