Influence of antibiotic treatment on the isolation rate of group a streptococci from peritonsillar abscesses

Abstract

In a prospective one-year study, group A streptococci were cultured from pus specimens from 13 of 71 patients (18%) with peritonsillar abscesses. The isolation rate was significantly lower (7/57=12%) in patients who had received antibiotic treatment before specimen collection than in patients who had not received such treatment (6/12=50%). Group A streptococcus antigen detection tests on pus, using a commercially available diagnostic kit, had a low sensitivity (5/13=38%). It was concluded that in patients treated with antibiotics prior to collection of specimens, the absence of group A streptococcus on culture does not rule out that this organism could have been the principal etiologic agent.

Key Words:

• antigen detection
• group A streptococci
• isolation rate
• peritonsillar abscess