Useful For

Detection of Chlamydia trachomatis DNA from genital specimens.

Clinical Information

Chlamydia trachomatis (CT) is the causative infectious agent for a variety of diseases in men: urethritis, proctitis, conjunctivitis, epididymitis, and Reiter’s Syndrome. Among woman, the consequences of chlamydial infections are severe if left untreated; CT infection can cause urethritis, cervicitis, conjunctivitis, endometritis, salpingitis (with subsequent infertility or ectopic pregnancy) and perihepatitis. Infants from infected mothers can develop conjunctivitis, pharyngitis, and pneumonia.

Chlamydia trachomatis (CT) is the most commonly diagnosed and reported sexually transmitted bacterial infection in Canada. The number of reported cases in Canada in 2006 was > 65,000 (202 per 100,000) and has been increasing annually. This, however, is an underestimate as the disease is often asymptomatic and therefore undiagnosed. CT infections are more common among females between the ages of 15-24 and young men aged 20-29.

Genital infections caused by Chlamydia trachomatis often go unrecognized as the majority of infected persons are asymptomatic. An estimated 3 out of 4 infected women and 1 out of 2 infected men will be asymptomatic initially.

Previously, culture was considered the gold standard test for diagnosis of Chlamydia trachomatis infections. However, organisms are labile in vitro and stringent specimen collection, transportation, and processing conditions are required to maintain organism viability, a necessity for culturing. Immunoassay tests are significantly less sensitive and specific than nucleic acid amplification testing (NAAT). NAAT is much more sensitive than culture, and is now considered the preferred test for detecting Chlamydia trachomatis.

Epidemiology in Newfoundland and Labrador can be found in the Communicable Disease Report:

https://www.health.gov.nl.ca/health/publichealth/cdc/mdr/Chlamydia_June_2011.pdf

Reference Values

NOT DETECTED

Interpretation

CT

DETECTED: indicates the presence of Chlamydia trachomatis DNA. This assay is not intended as a test of cure as non-viable CT may be detected when performed < 3 weeks after completion of therapy. In cases of treatment failure isolation/culture should be attempted.

NOT DETECTED: absence of Chlamydia trachomatis DNA.

INDETERMINATE: the specimen submitted contained substances inhibitory to the assay. Please recollect a specimen to complete follow up.

Clinical Reference

Essig, A. 2007. Chlamydia and Chlamydophilia, p. 1021-1035. In Murray, P. R., Baron, E. J., Jorgensen, J. H., Landry, M. L., and Pfaller, M. A. Manual of Clinical Microbiology, 9^th ed., vol. 2. ASM Press, American Society for Microbiology, Washington, DC.

Stamm, W. E., and Batteiger, B. E. 2010. Chlamydia trachomatis (Trachoma, Perinatal Infections, Lymphogranuloma Venereum, and Other Genital Infections, p. 2443-2461. In Mandell, D., Bennett, J. E., and Dolin, R. 2010. Principles and practice of infectious diseases, 7^th ed., vol. 2. Churchill Livingstone, Elsevier, Philadelphia, PA.

Roche Molecular Systems Inc. Cobas® 4800 CT/NG Test: Package insert. Roche Diagnostics GmbH, Mannheim.