survey of carrier rate of group a hemolytic streptococci

this study was undertaken in order to ascertain the carrier rate of group a hemolytic streptococci in the throats of pupils in selected schools of tehran, and to evaluate the role of socio-economical factors on carrier state. during the period of six months, 7020 children and adolescents, aged 10 to 17, were studied. these pupils were visited at their schools and their socio-economical level was determined by social workers. at the same time, throat cultures were obtained by sterile swabs and inoculated on blood agar plates immediately. indentation of hemolytic streptococcus, its grouping and typing were done by standard techniques in the laboratory. out of 7020 throat cultures, 522 positive results were seen, giving an average rate of 7.4%. type 25 and 12 were the most prevalent types. further analysis of the data indicates that girls have more positive cultures than boys (8.1%yand 6.8% respectively), and the month of december depicts the highest rate of carrier state of this micro-organism. mid socio-economical group has shown a higher rate than the other two groups. this could be due to a larger sample size, of that group 'which actually were obtained during the month of december. the pupils who had tonsillectomy in the past showed 40% lower carrier rate than the intact group.