Lab Test

Chlamydia trachomatis Detection by Nucleic Acid Amplification

CT, NAAT, STI, STD

Test Codes

EPIC: LAB6532, SOFT: ICTG

Department

Molecular Pathology

Instructions

Nucleic Acid Amplification testing (NAAT) is the preferred option for the detection of Chlamydia trachomatis (Ct). Swabs (urethral, endocervical), urine, and ThinPrep® PreservCyt liquid-based cytology specimens are acceptable for testing. ThinPrep® PreservCyt specimens offer the patient and physician an efficient means to perform Ct testing in conjunction with routine cytology and HPV testing as clinically indicated.

Specimen Collection Criteria

Collect: Swab, urine, or ThinPrep® PreservCyt specimen, as described below:

SWABS:

Female Endocervical:

  • Preferred specimen: Roche Cobas® PCR Female Swab Specimen Collection Kit.
  • Also acceptable: Swab specimen in UVT or UTM Transport Medium.

URINE (Male or Female):  

  • Preferred specimen: First void clean catch urine in Roche Cobas® PCR Urine Specimen Collection kit. 
  • Also acceptable:
    • First void clean catch urine in a sterile collection container or yellow top urine tube. (Minimum: 5.0 mL)
    • Midstream urine in a sterile container or yellow top urine tube. Midstream specimens have decreased clinical sensitivity and are of limited diagnostic value. (Minimum: 5.0 mL)
  • Chlamydia trachomatis tests MUST be ordered at the time of collection.
  • Add-on tests CANNOT be performed on urine specimens following testing on the Urinalysis Instrument.
ThinPrep® PRESERVCYT LIQUID BASED CYTOLOGY (Female endocervical):
  • Chlamydia trachomatis tests MUST be ordered at the time of collection.
  • Add-on tests CANNOT be performed once the ThinPrep® specimen has been processed for cytology and/or HPV testing.
  • Chlamydia trachomatis test results WILL be reported separately, and NOT as a component of the combined PAP/HPV report. 

Physician Office/Draw Specimen Preparation

Maintain swab and ThinPrep® specimens at room temperature (20-26°C or 68-78.8°F) prior to transport. Urine specimens must be refrigerated (2-8°C or 36-46°F) if not to be received in the Laboratory within 8 hours of collection.

Preparation for Courier Transport

Transport: All specimen types, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

  • Unlabeled specimens.
  • Specimens submitted in transport media other than those listed.
  • SurePath liquid-based cytology specimens.
  • Non genitourinary specimens require approval from the Medical Director or Supervisor.
  • Add-on requests for samples that have been previously run on the other instrumentation.

Inpatient Specimen Preparation

Specimens should be sent to the main Laboratory if received at Royal Oak. Specimens received at Farmington Hills should be sent to microbiology.

Storage

Specimen Stability for Testing:

Roche Cobas® PCR Female Swab
Room Temperature (20-26°C or 68-78.8°F): 365 days
Refrigerated (2-8°C or 36-46°F): 365 days
Frozen (-20°C/-4°F or below): Unacceptable

Swab Specimens in UVT or UTM Transport Medium
Room Temperature (20-26°C or 68-78.8°F): 2 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 14 days

Roche Cobas® PCR Urine Tube
Room Temperature (20-26°C or 68-78.8°F): 365 days
Refrigerated (2-8°C or 36-46°F): 365 days
Frozen (-20°C/-4°F or below): Unacceptable

Neat Urine Specimens
Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 180 days

ThinPrep® PreservCyt Specimens
Room Temperature (20-26°C or 68-78.8°F): 365 days
Refrigerated (2-8°C or 36-46°F): 365 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

UVT or UTM Transport Medium: Refrigerated (2-8°C or 36-46°F): 7 days

Roche Cobas® Swab or Urine Collection: Room Temperature (20-26°C or 68-78.8°F): 7 days

ThinPrep® PreservCyt Specimens Room Temperature (20-26°C or 68-78.8°F): 6 weeks

Laboratory

Royal Oak Clinical Molecular Pathology Laboratory

Performed

Monday – Saturday.
Results are usually available within 24 hours of receipt in the Laboratory (excluding weekends and holidays).

Reference Range

Negative for Chlamydia trachomatis.

Test Methodology

Real-time PCR Amplification and Detection (RT-PCR)- Roche Cobas® 4800 System.

This test is FDA approved for diagnostic purposes.

Interpretation

By report.

Clinical Utility

  • The presence or absence of Chlamydia trachomatis can be assessed in genitourinary specimens using DNA-based nucleic acid amplification technology, which has been shown to be more sensitive than culture. This test may be used for diagnostic or screening purposes for symptomatic or asymptomatic patients.
  • The submitted specimen may also be tested for the presence of Neisseria gonorrhoeae; two results can be made available from one clinical specimen. (See Neisseria gonorrhoeae Detection by Nucleic Acid Amplification.)

Reference

  1. Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR 2015 64(3):55-68.

CPT Codes

87491
LOINC: 21613-5

Contacts

Last Updated

6/17/2021

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