Detection and evaluation of Streptococcus pyogenes (Group A) as a superior infectious agent of acute pharyngitis among school age children

Abstract

Background: Streptococcus pyogenes Group A -(GAS), is a bacterium has gram-positive coccoid shaped, that appears in chains, and produces a small colonies with color like white to greyish, produces a clear zone of type β-hemolysis when cultivate within blood agar. GAS causes severe human disease mostly by three mechanisms include: the suppuration, as in cases pyoderma, and pharyngitis, immune-mediated inflammation and toxin elaboration. Causes respiratory tract infections, with acute pharyngitis, are common through childhood and adolescence. And that occur most commonly and frequently among the children between (5 and 15) years of age. Objective: This study for searching about infection of Iraqi children at school age with Streptococcal pharyngitis by Streptococcus pyogenes Group A (GAS). Patients and methods: Collection of (60) samples from school children at age between (6- 12) years suffered from acute pharyngitis, from many schools in different regions in Baghdad city, with (20) healthy children for control. from period January to April 2019. Two swabs were collected from each child, Swabbing the posterior pharynx and tonsils, for both the rapid antigen-detection test and culture, with dimension of serum antibodies to Streptolysin-O. Results: Results of Culture on Blood Agar for genus Streptococcus were in 32 (53%) patients were mostly in age group (6-8) years: 23(38%), was in males (10), in female (13), with total Medical history of infection (14) while in control total (4). Also specific result by rapid antigen-detection test, Streptococcus pyogenes detection were in: 25 (42%), mostly in age group (6-8) years, was 19 (32%), in male (8) and in female (11) with total Medical history of infection (7) while in control were (1) in total. Conclusion: In school age patients with signs and symptoms, revealing of streptococcal pharyngitis, a specific diagnosis should be determined by substitute a throat culture, or a rapid antigen-detection test with execution a throat culture, if the rapid antigen-detection test be negative, as a minimum in children in school age. But if the rapid antigen-detection test was positive, a throat culture will not desirable for diagnosis, nor is necessary after treatment, if symptoms were resolved.