Inverse association between Lancefield group G Streptococcus colonization and sore throat in slum and nonslum settings in Brazil.

Group G Streptococcus has been implicated as a causative agent of pharyngitis in outbreak situations, but its role in endemic disease remains elusive. We found an unexpected inverse association of Streptococcus dysgalactiae subsp. equisimilis colonization and sore throat in a study of 2,194 children of 3 to 15 years of age in Salvador, Brazil.