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Test Code LAB4602 CHLAMYDIA TRACHOMATIS + NEISSERIA GONORRHOEAE PCR

Additional Codes

Labcorp 183194

Specimen Type

Urine in Xpert Urine Transport Reagent tube (yellow top)

Vaginal/endocervical/cervix swab in Xpert Swab Specimen Collection Tube (pink top)

Throat/rectal swab in Xpert Swab Specimen Collection Tube (pink top)

 

USE ONLY GeneXpert Collection Transport Reagent for specimen collection.

Turnaround Time

24 Hours

Test Schedule

Daily 0500-2300

Sample Stability

Urine sample must be added to a Xpert Urine Specimen Collection Tube (pink top) Tube within 4 hours after collection. After placing specimen in the Xpert Specimen Collection Tube it is stable for up to 28 days at 2 - 30C.

Vaginal, Endocervical, Cervix, Throat, or Rectal sample must be immediately placed in the Xpert Swab Specimen Collection Tube (pink top). After placing specimen in the Xpert Specimen Collection Tube it is stable for up to 60 days at 2 - 30C.

Method

Cepheid GeneXpert Real-time PCR assay

Reference Ranges

Detected, Not Detected, or Invalid for Chlamydia trachomatis

Detected, Not Detected, or Invalid for Neisseria gonorrhoeae

Synonyms

CT/GC, CT/NG, CT, Chlam, GC, NG, Chlamydia Trachomatis, Neisseria Gonorrhoeae

CPT Codes

87491, 87591

Collection Instructions

Urine Specimen (Dirty) Collection Instructions:

  1. The patient should not have urinated for at least 1 hour prior to specimen collection. Patient should NOT cleanse genital area prior to collecting the specimen.
  2. Direct patient to provide first-catch urine (approximately 20 to 50 mL of the initial urine stream) into a urine collection cup free of any preservatives.
  3. Transfer approximately 7 mL of urine into the Xpert Urine Transport Reagent tube (yellow top) using the disposable transfer pipette up to the black dashed line (minimum volume 3mL).
  4. Tighten the cap securely on the BD Molecular Urine Sample Buffer tube.
  5.  Invert the reagent tube 3 to 4 times to ensure that the specimen and reagent are well mixed.
  6. Label tube with the patient information.
  7. Ship to laboratory at room temperature.

 

 Vaginal Specimen Collection Instructions:

·         Collect swab prior to pelvic, speculum, or bimanual exam.

·         No lubricant is used for the sample collection.

·         Do not collect at the posterior fornix

  1. Discard the large cleaning swab. Partially peel open the FLOQSwab in collection kit. Carefully insert the FLOQSwab 2 inches (5 cm) into the vagina.
  2. Rotate the swab for 10 to 30 seconds. Ensure the swab touches the wall of the vagina.
  3. Specimen must be transferred immediately into the Xpert Swab Specimen Collection Tube with the pink cap. Insert swab into collection tube and break the shaft at the score mark.
  4. Tightly recap the tube. Invert or gently shake tube 3-4 times.
  5.  Label the tube with patient information.
  6. Ship to laboratory at room temperature.

Cervix/Endocervical Specimen Collection Instructions:

  1. Partially open the large cleaning swab. Use the large cleaning swab to remove excess mucus from the cervical os and surround mucosa. Discard the large cleaning swab.
  2. Partially peel open the FLOQSwab in collection kit. Endocervical collection- carefully insert the swab into the endocervical canal, gently rotate the swab for 10 to 30 seconds. Cervix collection- swab the cervix and surrounding mucosa. Specimen must be transferred immediately into the Xpert Swab Specimen Collection Tube (pink top).
  3. Unscrew the cap of the Xpert Swab Specimen Collection Tube (pink top).
  4. Fully insert the swab into the Xpert Swab Specimen Collection Tube (pink top) so the tip is at the bottom after carefully removing cap so it can be used later to recap the specimen.
  5. Break the shaft at the score mark, taking care to avoid splashing. If the contents of the tube are spilled, use a new collection kit.
  6. Tightly recap the tube. Invert or gently shake tube 3-4 times.
  7. Label the tube with patient information.
  8. Ship to Laboratory at Room Temperature.

Throat Specimen Collection Instructions:

  1.  Discard large cleaning swab. Partially peel open the FLOQSwab in collection kit. Swab areas of the throat/pharynx (tonsil, posterior wall, uvula, posterior wall).      
  2. Withdraw the swab without touching the inside of the mouth. Specimen must be transferred immediately into the Xpert Swab Specimen Collection Tube with the pink cap.
  3. Unscrew the cap of the Xpert Swab Specimen Collection Tube (pink top).
  4. Fully insert the swab into the Xpert Swab Specimen Collection Tube (pink top) so the tip is at the bottom after carefully removing cap so it can be used later to recap the specimen.
  5. Break the shaft at the score mark, taking care to avoid splashing. If the contents of the tube are spilled, use a new collection kit.
  6. Tightly recap the tube. Invert or gently shake tube 3-4 times.
  7. Label the tube with patient information.     
  8. Ship to Laboratory at Room Temperature.

Rectal Specimen Collection Instructions:

  1. Discard large cleaning swab. Partially peel open the FLOQSwab in collection kit. Carefully insert swab approximately 1cm beyond the anal sphincter (so that the fiber tips are no longer visible).
  2. Rotate the swab for 10 to 30 seconds. Ensure the swab touches the wall of the vagina. Withdraw the swab. Specimen must be transferred immediately into the Xpert Swab Specimen Collection Tube with the pink cap.
  3. Unscrew the cap of the Xpert Swab Specimen Collection Tube (pink top).
  4. Fully insert the swab into the Xpert Swab Specimen Collection Tube (pink top) so the tip is at the bottom after carefully removing cap so it can be used later to recap the specimen.
  5. Break the shaft at the score mark, taking care to avoid splashing. If the contents of the tube are spilled, use a new collection kit.
  6. Tightly recap the tube. Invert or gently shake tube 3-4 times.
  7. Label the tube with patient information.
  8. Ship to Laboratory at Room Temperature.

Interfering Substances

Potential Interfering Substances: 

 CT/NG: Potentially interfering substances evaluated include blood and mucin with vaginal/endocervical specimens. Blood, mucin, bilirubin, and vagisil feminine powder with urine specimens.

Test Components

Chlamydia trachomatis, amplified probe technique

Neisseria gonorrhoeae, amplified probe technique

Specimen Rejection Criteria

  • Incorrect or expired transport medium
  • Any specimen that has leaked
  • Improper storage conditions during transport
  • Improper sample collection

Limitations

The Xpert CT/NG performance has not been evaluated in patients less than 14 years of age.  The Xpert CT/NG performance has not been evaluated in patients with a history of hysterectomy. Also it should not be used for sexual abuse cases.

Clinical Information

Chlamydia trachomatis (CT) are Gram-negative, non-motile, bacteria that exist as obligate intracellular parasites of eukaryotic cells due to their inability to synthesize ATP. The CT species is comprised of at least fifteen serovars that can cause disease in humans; serovars D through K are the major cause of genital chlamydial infections in men and women. Left untreated, CT can cause non-gonococcal urethritis, epididymitis, proctitis, cervicitis, and acute salpingitis. In women, untreated CT can lead to pelvic inflammatory disease (PID) in more than 40% of the infected population and render up to 20% infertile. PID can manifest as endometritis, salpingitis, pelvic peritonitis, and tubo-ovarian abscesses.

 

Neisseria gonorrhoeae (NG) are non-motile, Gram-negative diplococci, and the causative agent of gonorrheal disease. Gonorrhea is the second most commonly reported bacterial sexually transmitted disease (STD). The majority of urethral infections caused by NG among men produce symptoms that cause them to seek curative treatment, but among women, infections often do not produce recognizable symptoms until complications (e.g., PID) have occurred.

 

NG and CT infections are not limited to the genital tract but include extragenital sites, such as the pharynx and rectum. This is particularly true for men who have sex with men, where disease may be limited to the pharynx or rectum and may go undetected if only genital sites are tested. However, extragenital disease has also been reported in women. Improved detection of extragenital NG is critical for identifying patients who require treatment and may prevent development of drug resistance due to inadequate treatment regimens that do not cover extragenital sites.