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Updated: Aug 8, 2026
06:37
Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source
Published on: February 7, 2013
Summary
This study tracked hemolytic and group A streptococci in Nashville school children over 20 years. Positivity rates were highest in younger children and those from low socioeconomic backgrounds, with some antibody acquisition without disease.
Area of Science:
- Pediatric Infectious Diseases
- Bacteriology
- Epidemiology
Background:
- Streptococcal pharyngitis remains a significant public health concern, particularly in school-aged populations.
- Understanding the long-term incidence and prevalence of specific streptococcal strains is crucial for public health interventions.
- Previous studies have indicated variations in streptococcal infections based on age, season, and socioeconomic factors.
Purpose of the Study:
- To determine the incidence and prevalence of hemolytic and group A streptococci in a cohort of school children over a 20-year period.
- To identify the most common serotypes of group A streptococci isolated.
- To analyze trends in positivity rates based on age, season, race, and socioeconomic status.
Main Methods:
- Longitudinal study of 3,479 school children in Nashville, Tennessee, from 1953-1954 to 1973-1974.
- Analysis of 53,827 throat cultures for hemolytic and group A streptococci.
- Typing of group A streptococcal strains and statistical analysis of positivity rates across demographic and temporal variables.
Main Results:
- 17.98% of throat cultures were positive for hemolytic streptococci and 12.87% for group A streptococci.
- Predominant group A streptococcal types included 6, 1, 12, 4, 5, and 3.
- Positivity rates were highest in February, increased in younger children (ages 5-9), and were significantly higher in children from low socioeconomic areas, irrespective of race.
Conclusions:
- Hemolytic and group A streptococcal infections showed distinct epidemiological patterns over two decades.
- Age and socioeconomic status were significant factors influencing infection rates, while race was not.
- The findings suggest potential for type-specific antibody acquisition independent of clinical streptococcal disease.
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