Abstract
Presented here are the results of an external quality control survey organized by the Swiss Center for Quality Control (CSCQ) to evaluate the performance of direct antigen tests (DATs) widely used in Swiss medical practices and laboratories for the diagnosis of group A streptococcal pharyngitis. Twice yearly over a 4-year period, just over 100 participants were requested to analyze positive, weakly positive and negative samples provided to them by the CSCQ with their routinely used DATs and to send the results to the CSCQ. For 1,620 samples distributed, the CSCQ received 1,484 (91.6%) results obtained with 17 different DATs. The specificity of all DATs for negative samples was >91%. For samples containing abundant group A streptococcal antigen, sensitivities ranged from 59.1% to 95.5%; however, for samples containing low levels of antigen, the sensitivity was much lower for all DATs, ranging from 8.7% to 69.8%. Therefore, negative DAT results should be verified with well-performed cultures in order to assure the optimal care of patients with pharyngitis.
Similar content being viewed by others
References
Bisno AL (2001) Acute pharyngitis. N Engl J Med 344:205–211
Bisno AL, Gerber MA, Gwaltney JM, Kaplan EL, Schwartz RH (2002) Practice guidelines for the diagnosis and management of group A streptococcal pharyngitis. Clin Infect Dis 35:113–125
Needham CA, McPherson KA, Webb KH (1998) Streptococcal pharyngitis: impact of a high-sensitivity antigen test on physician outcome. J Clin Microbiol 36:3468–3473
Salkin IF, Limberger RJ, Stasik D (1997) Commentary on the objectives and efficacy of proficiency testing in microbiology. J Clin Microbiol 35:1921–1923
Facklam RR (1997) Screening for streptococcal pharyngitis: current technology. Infect Med 14:891–898
Kurtz B, Kurtz M, Roe M, Todd J (2000) Importance of inoculum size and sampling effect in rapid antigen detection for diagnosis of Streptococcus pyogenes pharyngitis. J Clin Microbiol 38:279–281
Johnson DR, Kaplan EL (2001) False-positive rapid antigen detection test results: reduced specificity in the absence of group A streptococci in the upper respiratory tract. J Infect Dis 183:1135–1137
Heiter BJ, Bourbeau PP (1993) Comparison of the Gen-Probe Group A Streptococcus Direct Test with culture and a rapid streptococcal antigen detection assay for diagnosis of streptococcal pharyngitis. J Clin Microbiol 31:2070–2073
Roe M, Kishiyama C, Davidson K, Schaefer L, Todd J (1995) Comparison of BioStar Strep A OIA optical immune assay, Abbott TestPack Plus Strep A, and culture with selective media for diagnosis of group A streptococcal pharyngitis. J Clin Microbiol 33:1551–1553
Rohner P, Matter L, Borst F, Stalder H (1992) Diagnosis of group A streptococcal pharyngitis: evaluation of a rapid test, culture and serology. Med Hyg 50:2433–2437
Tenjarla G, Kumar A, Dyke JW (1991) TestPack Strep A kit for the rapid detection of group A streptococci on 11,088 throat swabs in a clinical pathology laboratory. Am J Clin Pathol 96:759–761
Schlager TA, Hayden GA, Woods WA, Dudley SM, Hendley JO (1996) Optical immunoassay for rapid detection of group A beta-hemolytic streptococci. Should culture be replaced? Arch Pediatr Adolesc Med 150:245–248
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Morandi, PA., Deom, A., Mauris, A. et al. External Quality Control of Direct Antigen Tests to Detect Group A Streptococcal Antigen. Eur J Clin Microbiol Infect Dis 22, 670–674 (2003). https://doi.org/10.1007/s10096-003-1027-y
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10096-003-1027-y