History and Objectives: Due to prevalence of Streptococcal infections in children and adolescents and their complications and in order to determine the prevalence of carriers of these bacteria and their role in the ASO titer, this study was performed on 7-15 years old students in Kashan in 1375.
Materials and Methods: In the first stage a descriptive study was performed on 960 cases by random sampling and then a cohort study in 170 cases was carried out in the second stage. Sample from throat was obtained by means of a sterile swab and transferred to selective culture media containing crystal violet and blood agar. The plates were transferred to laboratory of medical faculty and incubated at 37° centigrade. After 24 hours bacteria were recognized by colonial morphology, B-hemolysis, catalase test, sensitivity to bacitracin disc and resistance to sulfamethoxazole trimethoprim. After 15 days, 5cc blood was obtained from the students and 5cc blood was obtained from the same numbers of normal children. The samples were immediately transferred to the laboratory. ASO titer was measured by Macro method.
Results: Bacterial isolation from selective culture media and blood agar was completely similar. Carrier state was defected in 8.85% of patients, 9.5% of boys and 7.96% of girls. Carrier state was most common (23.7%) in 13 years old and least common (1.2%) in 11 years old students. The prevalence of the carrier state was different in various areas of Kashan. The prevalence of the carrier state was also dependent on the number of children of the family. Comparing ASO titer in carriers and control group shows that 17.6% of carrier have abnormally high (>1/250) titers, while abnormal titer was detected in only 1.1% of the control group (P<0.001). The conclusion is that the bacteria can increase the ASO titer.
Conclusion: Due to prevalence of this bacterium among students and considering its late and irreversible complications, it is recommended essential therapeutic and hygienic measures be considered in this regard and also regarding the high prevalence of abnormally high ASO titer among carriers, interpretation of this test should be done with caution particularly in children and adolescents.
Saffari M, Pirouzmand A, Vali G R, Khorshidi A. Prevalence of Beta hemolytic group A Streptococcal carriers and its role in the ASO titer in students of Kashan in 1375 . Feyz 1999; 3 (2) :38-43 URL: http://feyz.kaums.ac.ir/article-1-510-en.html