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.
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.
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.
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.
From 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.
Accepted for publication October 21, 2014.
J. B. Dale is the inventor of certain technologies related to the development of group A streptococcal vaccines, which have been licensed by the University of Tennessee Research Foundation to Vaxent, LLC. J. B. Dale serves as the Chief Scientific Officer of Vaxent and is a member. The authors have no other conflicts of interest to disclose.
Supported by National Institutes of Health, UO1AI060592, awarded to J. B. Dale.
Address for correspondence: Milagritos Tapia, MD, Center for Vaccine Development, University of Maryland School of Medicine, 685 W. Baltimore St., Rm 480, Baltimore, MD 21201. E-mail: firstname.lastname@example.org