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Streptococcal pharyngitis in schoolchildren in Bamako, Mali
Milagritos D Tapia1, Samba O Sow, Boubou Tamboura
1From the *Division of Infectious Disease and Tropical Pediatrics, Department of Pediatrics and ¶Division of Geographic Medicine, Department of Medicine, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; †Centre pour le Développement des Vaccins-Mali, Bamako, Mali; ‡Department of Pediatrics, University of Virginia, Charlottesville, Virginia; and §University of Tennessee Health Science Center and Veterans Affairs Medical Center Research Service, Memphis, Tennessee.
Insights
Group A Streptococcus (GAS) pharyngitis treatment guidelines and vaccine strategies are crucial for reducing rheumatic heart disease in developing nations. This study in Mali identified GAS emm types to inform vaccine development and treatment protocols for sore throats in children.
Area of Science:
- Infectious Diseases
- Vaccinology
- Global Health
Background:
- Group A Streptococcus (GAS) pharyngitis is a significant cause of rheumatic heart disease in developing countries.
- Limited guidelines exist for the empiric treatment of pharyngitis in low-resource settings.
- Understanding GAS emm types is vital for developing effective GAS vaccines.
Purpose of the Study:
- To identify guidelines for the empiric treatment of pharyngitis in low-resource settings.
- To determine the emm types of GAS causing pharyngitis in African schoolchildren to inform GAS vaccine design.
Main Methods:
- Pharyngitis surveillance was conducted among 5-16 year olds in Bamako, Mali.
- Throat swabs were collected for GAS isolation and emm typing from students with sore throats.
- Clinical signs, including cervical adenopathy, were recorded.
Main Results:
- GAS was isolated from 25.5% of sore throat episodes.
- Painful cervical adenopathy was a strong indicator of GAS infection (89.8% of GAS-positive children).
- A 30-valent GAS vaccine could potentially protect against nearly 75% of GAS infections in this population, covering 14 prevalent emm types.
Conclusions:
- Targeted antibiotic administration for children with sore throat and tender cervical adenopathy can effectively treat GAS while minimizing unnecessary antibiotic use.
- A broadly covering GAS vaccine, targeting prevalent emm types in Bamako, shows promise for reducing rheumatic heart disease in low-resource settings.
Background:
Group A streptococcus (GAS) pharyngitis is associated with high rates of rheumatic heart disease in developing countries. We sought to identify guidelines for empiric treatment of pharyngitis in low-resource settings. To inform the design of GAS vaccines, we determined the emm types associated with pharyngitis among African schoolchildren.
Methods:
Surveillance for pharyngitis was conducted among children 5-16 years of age attending schools in Bamako, Mali. Students were encouraged to visit a study clinician when they had a sore throat. Enrollees underwent evaluation and throat swab for isolation of GAS. Strains were emm typed by standard methods.
Results:
GAS was isolated from 449 (25.5%) of the 1,759 sore throat episodes. Painful cervical adenopathy was identified in 403 children (89.8%) with GAS infection and was absent in 369 uninfected children (28.2%). Emm type was determined in 396 (88.2%) of the 449 culture-positive children; 70 types were represented and 14 types accounted for 49% of isolates. Based on the proportion of the 449 isolates bearing emm types included in the 30-valent vaccine (31.0%) plus nonvaccine types previously shown to react to vaccine-induced bactericidal antibodies (44.1%), the vaccine could protect against almost 75% of GAS infections among Bamako schoolchildren.
Conclusions:
Two promising strategies could reduce rheumatic heart disease in low-resource settings. Administering antibiotics to children with sore throat and tender cervical adenopathy could treat most GAS-positive children while reducing use of unnecessary antibiotics for uninfected children. Broad coverage against M types associated with pharyngitis in Bamako schoolchildren might be achieved with the 30-valent GAS vaccine under development.
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