Increasing severity of invasive group A streptococcal disease in Australia: clinical and molecular epidemiological features and identification of a new virulent M-nontypeable clone

Clin Infect Dis. 1995 Nov;21(5):1220-7. doi: 10.1093/clinids/21.5.1220.


We conducted a 12-year review of all cases of group A streptococcal (GAS) bacteremia that were seen at Royal Children's Hospital in Melbourne, Australia, from 1982 through 1993. Forty-two cases were identified. There was a trend towards increased incidence of infections, as well as a clear increase in their severity, during the study period; more previously healthy children were affected during the last 6 years of the study (80% of cases) than during the first 6 years (47% of cases), and more complications occurred during the latter period than during the former (40% vs. 20%, respectively, with an 88% complication rate over the last 12 months). Seventy-four GAS isolates (41 invasive, 23 noninvasive, and 10 indeterminate) were analyzed. An M type 1 clone that was positive for the pyrogenic exotoxin A gene (speA) and that has been found to cause invasive disease in the Northern Hemisphere was most frequent among invasive isolates. Molecular typing also identified a genetically distinct strain that was virulent, mucoid, and M nontypable. Invasive GAS disease in Melbourne has become increasingly aggressive. Newer typing methods should be used in conjunction with traditional serotyping in order to maintain epidemiological surveillance of virulent strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Australia / epidemiology
  • Bacteremia / epidemiology*
  • Bacteremia / microbiology*
  • Bacterial Proteins*
  • Bacterial Typing Techniques
  • Child
  • Child, Preschool
  • Exotoxins / genetics
  • Genes, Bacterial
  • Humans
  • Infant
  • Membrane Proteins*
  • Molecular Epidemiology
  • Retrospective Studies
  • Streptococcal Infections / epidemiology*
  • Streptococcal Infections / microbiology*
  • Streptococcus pyogenes* / classification
  • Streptococcus pyogenes* / genetics
  • Streptococcus pyogenes* / pathogenicity
  • Virulence


  • Bacterial Proteins
  • Exotoxins
  • Membrane Proteins
  • SpeA protein, Streptococcus pyogenes
  • erythrogenic toxin