Performance of an enzyme immunoassay test and anaerobic culture for detection of group A streptococci in a pediatric practice versus a hospital laboratory.
The ability of pediatricians and hospital laboratory personnel to detect group A streptococci in patients with suspected streptococcal pharyngitis was evaluated using the TestPack Strep A and anaerobic culture. Duplicate throat specimens (for similar processing by both the pediatricians and laboratory technologists) were simultaneously collected on rayon-tipped swabs from patients with symptoms of pharyngitis. Each swab was first inoculated to a 5% sheep blood agar plate, then tested for group A streptococcus antigen using the TestPack Strep A according to the manufacturer's instructions. Cultures were incubated anaerobically at 35 degrees C for 2 nights unless positive after 1 night. Group A streptococci were identified using specific antisera. Pediatric office or laboratory cultures from 112 (31.3%) of the 358 patients contained group A streptococci. Of the patients with positive cultures, 96 (85.7%) and 107 (95.5%) were detected by the pediatricians and laboratory, respectively. Respective findings with the TestPack Strep A by the pediatricians and laboratory were sensitivity 68.8% and 74.8%, specificity 94.3% and 95.6%, predictive value of a positive result 81.5% and 87.9%, and predictive value of a negative result 89.2% and 89.9%. Anaerobic culture was significantly more sensitive than the TestPack Strep A for detection of group A streptococci by both the pediatricians (P less than 0.005) and laboratory personnel (P less than 0.05).
Kellogg
J A
JA
Landis
R C
RC
Nussbaum
A S
AS
Bankert
D A
DA
D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000032:analysis; D001421:Bacteria, Anaerobic; D001431:Bacteriological Techniques; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques; D003470:Culture Media; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D009819:Office Visits; D009960:Oropharynx / Q000382:microbiology; D010612:Pharyngitis / Q000382:microbiology; D011933:Reagent Kits, Diagnostic; D013297:Streptococcus pyogenes / Q000276:immunology / Q000302:isolation & purification*
D000942:Antigens, Bacterial; D003470:Culture Media; D011933:Reagent Kits, Diagnostic