Determine upper limit of normal range of antistreptolysin-O titer in normal school children from 5 to 15 years old

Abstract

ObjectiveTo determine upper limit of normal range of antistreptolysin-O (ASO) titer in normal school children from 5 to 15 years old in Menoufia Governorate.BackgroundAlthough ASO titer has provided a useful guideline to physicians this has been shown to vary with age, geographical location, and site of infection.Patients and methodsA cross-sectional study was carried out in Menoufia Governorate and the samples were collected from outpatient clinics of Menoufia university hospital other than infection (by advertising in the outpatient clinics for analysis streptococcus laboratory for free in children aged 5–15 years) in the period from July 2016 to May 2017. Two hundred children aged 5–15 years were participated in this study after consent from their parents. The children were categorized into two groups: group 1: include children aged 5–10 years and group 2: include children aged 11–15 years. Full history, routine, physical examination, and special investigations were taking.ResultsThere was statistically significant difference between residence and social classes in the studied group. Also, there was statistically significant difference between age groups regarding ASO titer among rural patients. There was highly significant correlation between number of attacks of acute follicular tonsillitis with ASO titer level, age groups, and social classes.ConclusionThe upper limit of normal ASO titer in normal Egyptian children is quite high, reaching up to 398.5 IU/ml. Therefore, an isolated high ASO titer is not sufficient to diagnose acute rheumatic fever. Basal levels of ASO titer increase with age but age does not affect the peak level during acute streptococcal infection. Additional studies will be required for establishment of standard values to avoid over diagnosis of acute rheumatic fever and complications of long-acting penicillin.