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. 1993 Jul;31(7):1892–1895. doi: 10.1128/jcm.31.7.1892-1895.1993

Confirmation of positive results for chlamydial antigen by the Chlamydiazyme assay: value of repeated testing and a blocking antibody assay.

M A Olsen 1, A R Sambol 1
PMCID: PMC265652  PMID: 8349769

Abstract

We studied the specificity of the Abbott Chlamydiazyme test for detection of Chlamydia trachomatis antigen by means of a specific blocking antibody test. A total of 457 previously positive specimens were tested; 22 did not block in the blocking antibody test, 39 did not repeat as positive, and 396 were confirmed as positive. The distribution of A492 values obtained with specimens which did not repeat as positive was nonrandom and was concentrated between the cutoff values and 0.400. The positive predictive value of the Chlamydiazyme assay after initial testing was 86.7% (396 of 457), but the positive predictive value increased to 94.7% (396 of 418) if specimens which were not repeatedly positive were considered negative. We recommend routinely repeating the Chlamydiazyme assay for all specimens which give A492 values between the cutoff and 0.400 to eliminate many false-positive results. Use of the blocking antibody reagent can then be reserved for confirming only specimens which are repeatedly positive.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baselski V. S., McNeeley S. G., Ryan G., Robison M. A comparison of nonculture-dependent methods for detection of Chlamydia trachomatis infections in pregnant women. Obstet Gynecol. 1987 Jul;70(1):47–52. [PubMed] [Google Scholar]
  2. Hallander H., Jonsson P., Gästrin B. Value of confirmation of Chlamydiazyme enzyme immunoassay results in the detection of Chlamydia trachomatis. Eur J Clin Microbiol Infect Dis. 1992 Jun;11(6):550–552. doi: 10.1007/BF01960813. [DOI] [PubMed] [Google Scholar]
  3. Hipp S. S., Han Y., Murphy D. Assessment of enzyme immunoassay and immunofluorescence tests for detection of Chlamydia trachomatis. J Clin Microbiol. 1987 Oct;25(10):1938–1943. doi: 10.1128/jcm.25.10.1938-1943.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Howard L. V., Coleman P. F., England B. J., Herrmann J. E. Evaluation of chlamydiazyme for the detection of genital infections caused by Chlamydia trachomatis. J Clin Microbiol. 1986 Feb;23(2):329–332. doi: 10.1128/jcm.23.2.329-332.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Iwen P. C., Blair T. M., Woods G. L. Comparison of the Gen-Probe PACE 2 system, direct fluorescent-antibody, and cell culture for detecting Chlamydia trachomatis in cervical specimens. Am J Clin Pathol. 1991 Apr;95(4):578–582. doi: 10.1093/ajcp/95.4.578. [DOI] [PubMed] [Google Scholar]
  6. Kellogg J. A. Clinical and laboratory considerations of culture vs antigen assays for detection of Chlamydia trachomatis from genital specimens. Arch Pathol Lab Med. 1989 May;113(5):453–460. [PubMed] [Google Scholar]
  7. Kellogg J. A., Seiple J. W., Hick M. E. Cross-reaction of clinical isolates of bacteria and yeasts with the chlamydiazyme test for chlamydial antigen, before and after use of a blocking reagent. Am J Clin Pathol. 1992 Mar;97(3):309–312. doi: 10.1093/ajcp/97.3.309. [DOI] [PubMed] [Google Scholar]
  8. Kellogg J. A., Seiple J. W., Levisky J. S. Efficacy of duplicate genital specimens and repeated testing for confirming positive results for chlamydiazyme detection of Chlamydia trachomatis antigen. J Clin Microbiol. 1989 Jun;27(6):1218–1221. doi: 10.1128/jcm.27.6.1218-1221.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Kellogg J. A., Seiple J. W., Murray C. L., Levisky J. S. Effect of endocervical specimen quality on detection of Chlamydia trachomatis and on the incidence of false-positive results with the Chlamydiazyme method. J Clin Microbiol. 1990 Jun;28(6):1108–1113. doi: 10.1128/jcm.28.6.1108-1113.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Lefebvre J., Laperrière H., Rousseau H., Massé R. Comparison of three techniques for detection of Chlamydia trachomatis in endocervical specimens from asymptomatic women. J Clin Microbiol. 1988 Apr;26(4):726–731. doi: 10.1128/jcm.26.4.726-731.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Moncada J., Schachter J., Bolan G., Engelman J., Howard L., Mushahwar I., Ridgway G., Mumtaz G., Stamm W., Clark A. Confirmatory assay increases specificity of the chlamydiazyme test for Chlamydia trachomatis infection of the cervix. J Clin Microbiol. 1990 Aug;28(8):1770–1773. doi: 10.1128/jcm.28.8.1770-1773.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Mårdh P. A., Elbagir A. N., Stenberg K. Use of blocking reagent to confirm enzyme immunoassay results in chlamydial conjunctivitis. Eur J Clin Microbiol Infect Dis. 1990 Apr;9(4):292–293. doi: 10.1007/BF01968065. [DOI] [PubMed] [Google Scholar]
  13. Ryan R. W., Kwasnik I., Steingrimsson O., Gudmundsson J., Thorarinsson H., Tilton R. C. Rapid detection of Chlamydia trachomatis by an enzyme immunoassay method. Diagn Microbiol Infect Dis. 1986 Sep;5(3):225–234. doi: 10.1016/0732-8893(86)90006-4. [DOI] [PubMed] [Google Scholar]
  14. Schwebke J. R., Stamm W. E., Handsfield H. H. Use of sequential enzyme immunoassay and direct fluorescent antibody tests for detection of Chlamydia trachomatis infections in women. J Clin Microbiol. 1990 Nov;28(11):2473–2476. doi: 10.1128/jcm.28.11.2473-2476.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Smith J. W., Rogers R. E., Katz B. P., Brickler J. F., Lineback P. L., Van der Pol B., Jones R. B. Diagnosis of chlamydial infection in women attending antenatal and gynecologic clinics. J Clin Microbiol. 1987 May;25(5):868–872. doi: 10.1128/jcm.25.5.868-872.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Van Dyck E., Samb N., Sarr A. D., Van de Velden L., Moran J., Mboup S., Ndoye I., Lamboray J. L., Meheus A., Piot P. Accuracy of two enzyme immunoassays and cell culture in the detection of Chlamydia trachomatis in low and high risk populations in Senegal. Eur J Clin Microbiol Infect Dis. 1992 Jun;11(6):527–534. doi: 10.1007/BF01960808. [DOI] [PubMed] [Google Scholar]

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