Diagnosis of group A beta-hemolytic streptococcal pharyngitis. Use of antigen detection tests.

Early diagnosis and prompt initiation of antibiotic therapy for group A beta-hemolytic streptococcal pharyngitis can shorten the duration of the clinical illness and reduce the period of infectivity. This in turn may expedite a patient's return to school or day care, as well as a parent's return to work. Antigen detection tests are available that can provide a rapid diagnosis of group A beta-hemolytic streptococcal pharyngitis and can facilitate the prompt initiation of antibiotic therapy. In addition, these antigen detection tests can provide a rapid exclusion of group A beta-hemolytic streptococcal pharyngitis and thereby prevent the initiation of unnecessary antibiotics in patients with nonstreptococcal pharyngitis. However, before throat cultures on blood agar plates are totally abandoned and completely replaced by antigen detection tests, a number of additional studies are needed. The consequences of false-negative and false-positive antigen detection tests need to be determined. The accuracy of the antigen detection test as performed in physicians' offices needs to be compared with traditional culture methods performed in physicians' offices and not with an "idealized" standard. Finally, investigations need to be initiated to determine the impact of different antigen detection tests on the revenues and work flow in various practice settings, as well as their direct impact on patient care.