TY - JOUR
T1 - Evaluation of the Strep A OIA® assay versus culture methods
T2 - Ability to detect different quantities of Group A Streptococcus
AU - Kuhn, Susan
AU - Davies, H. Dele
AU - Katzko, Gary
AU - Jadavji, Taj
AU - Church, Deirdre L.
N1 - Funding Information:
We acknowledge the contributions of the Community G.A.S. Study Group (Drs. T. Govender, H. Schroter, S. Wainer, J. Heard, S. Cardwell, J. Wu, P. Niemann, N. Cooper, D. Palmer, T. Prince, M. Wright, E. Sheleyko, C. Nijssen-Jorden, and Ms. M. Lovegren). Special thanks also go to the microbiology technologists at the Alberta Children’s Hospital, and to research assistants D. Ma, D. Buser, and N. Martin. This study was presented in part at the 96th Annual American Society of Microbiology Meeting, May 1996, New Orleans, Louisiana. Dr. H. D. Davies is a Clinical Investigator of the Alberta Foundation for Medical Resesarch. Dr. S. Kuhn was supported by the Canadian Infectious Diseases Society Glaxo Wellcome Research Fellowship Award. The study was supported by a grant from the Alberta Children’s Hospital Foundation. Randolph et al. 1984 Taubert et al. 1991
PY - 1999/8
Y1 - 1999/8
N2 - The Strep A OIA® assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA® assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5% sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA® was then performed. A total of 144 of 363 (39.7%) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7%), THB culture detected 128 of 144 (88.9%), and the Strep A OIA® assay detected 129 of 144 (89.6%). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7%) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9%, specificity of 96.6%, a positive predictive value of 93.9%, and a negative predictive value of 98.3%. Although the performance of the Strep A OIA® assay had similar specificity (96.5%) and positive predictive value (93.8%) compared with the combined results of the two culture methods, the sensitivity (89.0%) and negative predictive value (93.6%) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA® assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0%) versus a moderate (3+) or heavy (4+) growth (98.1%) of GAS. Although the Strep A OIA® assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures. Copyright (C) 1999 Elsevier Science Inc.
AB - The Strep A OIA® assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA® assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5% sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA® was then performed. A total of 144 of 363 (39.7%) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7%), THB culture detected 128 of 144 (88.9%), and the Strep A OIA® assay detected 129 of 144 (89.6%). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7%) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9%, specificity of 96.6%, a positive predictive value of 93.9%, and a negative predictive value of 98.3%. Although the performance of the Strep A OIA® assay had similar specificity (96.5%) and positive predictive value (93.8%) compared with the combined results of the two culture methods, the sensitivity (89.0%) and negative predictive value (93.6%) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA® assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0%) versus a moderate (3+) or heavy (4+) growth (98.1%) of GAS. Although the Strep A OIA® assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures. Copyright (C) 1999 Elsevier Science Inc.
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U2 - 10.1016/S0732-8893(99)00027-9
DO - 10.1016/S0732-8893(99)00027-9
M3 - Article
C2 - 10459477
AN - SCOPUS:0032764873
SN - 0732-8893
VL - 34
SP - 275
EP - 280
JO - Diagnostic Microbiology and Infectious Disease
JF - Diagnostic Microbiology and Infectious Disease
IS - 4
ER -