Testing for group a streptococci.

Context: Laboratory diagnosis of group A streptococcal pharyngitis in physician office and small-hospital laboratories.

Objective: To characterize laboratory practices for the diagnosis of group A streptococcal pharyngitis and to identify opportunities for improvement.

Design: Voluntary self-assessment questionnaire, used to assess the laboratory practices of 790 laboratories subscribing to the College of American Pathologists Excel Microbiology Proficiency Testing Program.

Results: We observed discrepancies between self-reported and recommended specimen collection and laboratory testing practices for some laboratories. The most notable discrepancies were failing to provide a written specimen-collection procedure (17.8%), sampling the tongue and oral mucosa (2%), failing to always perform back-up cultures when rapid antigen test results were negative (57.5%), and finalizing culture reports within 24 hours or less (34.0%). Additionally, among those respondents who used the bacitracin disk, 57.9% (277 respondents) applied the disk directly onto a primary plate.

Conclusions: Opportunities exist to improve testing practices for the diagnosis of group A streptococcal pharyngitis for some physician office and small-hospital laboratories.