a study was undertaken to find out the prevalence rate or rheumatic fever (r.f.) and rheumatic heart disease (r.h.d.) among pupils in selected schools of tehran, and to evaluate the rate of socio-economical factors on prevalence rate of this disease. during period of 5 months, 6, 183 children and adolescents aged 5-17 were studied. out of 6,183 pupils, 3, 680 were boys (59.5) and 2,503 were gir...