در كودكان و نوجوانان 14-7 ساله شهرستان شهركرد، 6731 )ASO(O بررسي تيتر آنتي استرپتوليزين

Anti-streptolysin 0 (ASO) titer in children and adolescents (7-14 years old) of Shahrekord, 1998

Rheumatic fever is a delayed and non-suppurative streptococcal infection of upper respiratory tracts. Its diagnosis relies on clinical findings and supportive evidence of a recent group A streptococcal infection. The latter may be provided by elevated or rising ASO titer. Since normal range of ASO titer depends on the test type, age and geographical area, it should be interpreted cautiously. Because a normal range has not been established for this area, we determined the median, mode and upper limit of normal ASO titer in healthy children, and adolescentʹs sera in this city. We also investigated the relation of ASO titer with some background variables. This cross sectional study was performed in the spring of 1998. 400 students (7-14 years old) were selected from 19 primary and guidance schools by a random-stratified method of sampling. The exclusion criteria were 1- history of recent streptococcal infection, 2- evidence of streptococcal infection by physical examination, 3- history of rheumatic fever in the student or a family member. The median, mode and upper limit of normal ASO titer was 166 T.U. (Todd unit) Using a Mann-Whitney-U test revealed no significant differences between ASO titers in 5ifferent age and sex groups. Statistical analysis revealed a significant relation between ASO titers and family size and socioeconomic status. Although the upper limit of normal of titers in our study was different from other studies but the prevalence of high ASO titers in our study was similar to other findings. This confirms that a specific cut-off point level cannot be used as a standard level of normal ASO titer everywhere and it varies from site to site.