Epidemiology of Streptococcus dysgalactiae subsp. equisimilis in tropical communities, Northern Australia

Emerg Infect Dis. 2007 Nov;13(11):1694-700. doi: 10.3201/eid1311.061258.

Abstract

Streptococcus dysgalactiae subsp. equisimilis (groups C and G streptococci [GCS/GGS]) is an increasingly recognized human pathogen, although it may follow indirect pathways. Prospective surveillance of selected households in 3 remote Aboriginal communities in Australia provided 337 GCS/GGS isolates that were emm sequence-typed. Lancefield group C isolates (GCS) were localized to specific households and group G isolates (GGS) were more evenly distributed. GCS/GGS was more frequently recovered from the throat than group A streptococci (GAS [S. pyogenes]) but rarely recovered from skin sores, and then only with Staphylococcus aureus or GAS. Symptomatic GGS/GGC pharyngitis was also rare. Specific emm sequence types of GCS/GGS did not appear to cycle through the communities (sequential strain replacement) in a manner suggesting acquisition of type-specific immunity. These communities already have high levels of streptococcal and poststreptococcal disease. GCS/GGS may increase in importance as it acquires key virulence factors from GAS by lateral gene transfer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Australia / epidemiology
  • Child
  • Humans
  • Native Hawaiian or Other Pacific Islander*
  • Pharynx / microbiology
  • Population Surveillance / methods
  • Prospective Studies
  • Rheumatic Fever / epidemiology
  • Rheumatic Fever / microbiology
  • Rheumatic Heart Disease / epidemiology
  • Rheumatic Heart Disease / microbiology
  • Skin / microbiology
  • Streptococcal Infections / epidemiology*
  • Streptococcal Infections / microbiology
  • Streptococcus / genetics
  • Streptococcus / isolation & purification*
  • Tropical Climate