Background: in 1998, an unexpected increase of group A streptococci (GAS) i
n blood cultures was observed at our institution.
Materials and Methods: To determine whether they were from unrelated sporad
ic cases or attributable to a com mon source, all isolates were analyzed by
pulsed-field gel electrophoresis (PFGE) and by automated ribotyping,
Results: Two clusters were found. All isolates, except one, of cluster 2 ha
d been isolated from intravenous drug abusers.
Conclusion: All patients were hospitalized either in different hospitals or
at different times in the same hospitals indicating that the putative comm
on source is to be found in the drug community rather than in a particular