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Microbiological and epidemiological study of streptococcal sore throat at a children's clinic: a one-year study
Insights
Beta-hemolytic streptococci caused 26% of upper respiratory infections in children, with peak incidence in ages 5-8. Most strains were group A, sensitive to penicillin but some resistant to tetracycline.
Area of Science:
- Pediatrics
- Microbiology
- Infectious Diseases
Background:
- Upper respiratory tract infections (URTIs) are common in children.
- Bacterial and viral pathogens cause pharyngitis, necessitating accurate diagnosis and treatment.
Purpose of the Study:
- To investigate the prevalence and characteristics of beta-hemolytic streptococci in pediatric URTIs.
- To determine the etiological agents of pharyngitis in children and their antibiotic susceptibility.
Main Methods:
- Throat cultures were performed on 578 children with URTIs over a 12-month period.
- Isolated beta-hemolytic streptococci were identified, grouped (A, C, G), and typed (T and M antigens).
- Antibiotic susceptibility testing was conducted on isolated strains.
Main Results:
- Beta-hemolytic streptococci were isolated from 26% of patients; viral causes accounted for 74%.
- Streptococcal pharyngitis peaked in ages 5-8, while viral pharyngitis was most common in ages 2-6.
- Group A beta-hemolytic streptococci were predominant (86%), with types 1 and 12 being most prevalent.
- All isolates were sensitive to penicillin, erythromycin, and chloramphenicol; 11 strains showed tetracycline resistance.
Conclusions:
- Beta-hemolytic streptococci, particularly group A, are significant contributors to pediatric URTIs.
- Understanding seasonal and age-related incidence aids in diagnosis and management.
- Emerging antibiotic resistance, notably to tetracycline, warrants monitoring.
Abstract:
From October 1973 to September 1974, throat cultures were taken from 578 patients who referred to the Children's Clinic with upper respiratory tract infection. One hundred fifty-one (26%) of the sick children yielded beta-hemolytic streptococci and 427 (74%) of the pharyngitis cases were considered as viral. The most susceptible ages for streptococcal and viral pharyngitis were 5-8 and 2-6 years respectively. The peak seasonal incidence for streptococcal sore throat was from late autumn to early spring. There was a positive correlation between the incidence of upper respiratory infection and streptococcal isolation. From 100 strains of beta-hemolytic streptococci isolated and tested, 86 were group "A", 4 group "C", 2 group "G" and 8 non-groupable. From 86 group "A" strains. 71 (82%) were typable by agglutination ("T"-typing), but only 49 (57%) by precipitation ("M"-typing). The most prevalent "M" types were types 1 and 12. There was 95% correlation between serological and bacitracin disk method for grouping of hemolytic streptococci. All strains isolated were sensitive to penicillin, erythromycin and chloramphenicol, but 11 strains were resistant to tetracyclin.