system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Adult, Electrophoresis, Gel, Pulsed-Field, Female, Humans, Male, Ribotyping, Streptococcal Infections, Streptococcus pyogenes, Substance Abuse, Intravenous, Switzerland.
user
Do automated ribotyping and pulsed-field gel electrophoresis reveal a cluster of group A streptococci in intravenous drug abusers? Context: In 1998, an unexpected increase of group A streptococci (GAS) in blood cultures was observed at our institution. To determine whether they were from unrelated sporadic cases or attributable to a common source, all isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and by automated ribotyping. Two clusters were found. All isolates, except one, of cluster 2 had been isolated from intravenous drug abusers.
assistant
All patients were hospitalized either in different hospitals or at different times in the same hospitals indicating that the putative common source is to be found in the drug community rather than in a particular hospital. Final Decision: yes