Chlamydia trachomatis / Neisseria. gonorrhoeae DNA  

 
IMPORTANT! Pre-approval needed from state or local health department. Local or State Health Department. Send approval to NPHL@unmc.edu or call (402) 559-9444.

NPHL has moved to an electronic ordering system, NUlirt, and it is now the preferred method to order all tests. Once ordered, print a "batch list" (see NUlirt Guide).

Forms Required - Nulirt batch list or NPHL Test Request Form (completed in entirety) must accompany the specimen to include the following information: symptoms and date of onset, pregnancy status, travel and vaccine history. Testing will not be performed without all required information.

Please call NPHL Client Services at (402) 559-2440 or toll free at (800) 334-0459 for further clarification.

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Test: Chlamydia trachomatis / Neisseria gonorrhoeae Amplified Probe  
Synonym: STD PCR assay, Chlamydia/GC Nucleic acid amplification test (NAAT)  
Method: Qualitative Target Amplification Nucleic Acid Probe (GenProbe APTIMA®)  
Availability: Monday - Friday; results on the same day if received before 0800  
Specimen: Male urethral, endocervical, rectal, throat, urine, and vaginal

Collection kits available from Regional Pathology Services  
Collection Device: Male urethral, endocervical, rectal, and throat use the APTIMA Unisex Swab Specimen Collection Kit; vaginal use the APTIMA Vaginal Swab Specimen Collection Kit; urine use the APTIMA Urine Specimen Collection Kit for male and female.

Collection:

Male urethral: discard large cleaning swab and insert the collection swab (blue shaft) 2 - 4 cm into the urethra and rotate for 2 - 3 seconds. Immediately place the swab into the transport tube. Break the swab at the score line, recap, and label tube with patient information, specimen source, date and time collected.

Endocervical: Remove excess mucus and blood from the endocervical opening using the large cleaning swab (white shaft) and discard. Insert the collection swab (blue shaft) into the cervical canal and rotate for 10 - 30 seconds. Immediately place the swab into the transport tube. Break the swab at the score line, recap, and label tube with patient information, specimen source, date and time collected.

Rectal: discard large cleaning swab and insert the collection swab (blue shaft) into the anal canal and rotate for 15 - 30 seconds. Immediately place the swab into the transport tube. Break the swab at the score line, recap, and label tube with patient information, specimen source, date and time collected.

Throat: discard large cleaning swab and instruct the patient to tilt head backwards, open mouth and say “ah.” While using a tongue depressor, insert the collection swab (blue shaft) into the mouth without touching the lips, teeth, tongue, or cheeks and gently swab the tonsillar area side to side while making contact with the inflamed or purulent sites. Immediately place the swab into the transport tube. Break the swab at the score line, recap, and label tube with patient information, specimen source, date and time collected.

Urine: patient should NOT urinate for at least 1 hour prior to collection. Have the patient collect 20 - 30 mL of the initial urine into the collection cup. Within 24 hours of collection, transfer 2 mL of urine (using the pipette provided) into the transport tube (urine level should fall between the black lines on the transport tube). Cap the tube tightly and label with patient information, specimen source, date and time collected.

Vaginal: hold the swab, placing thumb and forefinger in the middle of the swab shaft covering the score line. Do not hold the swab shaft below the score line. Insert the swab (pink shaft) into the vagina about 2 inches past the introitus and rotate for 10 - 30 seconds making sure the swab touches the walls of the vagina. Immediately place the swab into the transport tube. Break the swab at the score line, recap, and label tube with patient information, specimen source, date and time collected.  
Volume: 1 swab or 20 - 30 mL urine  
Storage/Transport:

Swabs in APTIMA transport media can be stored and transported at 2 - 30 °C within 30 days of collection; unpreserved urine can be stored and transported at 2 - 30 °C within 24 hours of collection; and preserved urine can be stored and transported at 2 - 30 °C within 30 days of collection.

 
Unacceptable: Swabs other than those in the APTIMA collection kit (including wooden swabs), swabs not placed in the transport medium, the large white swab which is used only for cleaning of the endocervix, and specimens stored at ambient or refrigerator temperatures past the stability date.  
Specimen Stability: Collection kit specimens are stable at ambient or refrigerated for 1 month and frozen for 3 months. Unpreserved urine specimens are stable at ambient for 24 hours.  
Reference Interval: Negative for C. trachomatis / N. gonorrhoeae
Postive for C. trachomatis and/or N. gonorrhoeae  
Reportable Disease: All positive C. trachomatis and N. gonnorhoeae are reportable  
Comments: A negative result does not preclude the presence of a C. trachomatis or N. gonorrhoeae infection because results are dependent on adequate specimen collection, absence of inhibitors, and sufficient rRNA to be detected.

The positive predictive value of the test varies dependent on the disease prevalence in the population, the patient's gender, and the specimen source. According to CDC guidelines, positive results should be considered presumptive evidence of infection.

If an indeterminate result is reported, submit a new specimen if indicated or treat patient based on clinical judgment.

Culture is recommended as the standard for detection in suspected sexual abuse and for suspected failure of therapy.  
Revised: 2/13/2012 
If you have questions about proper specimen collection, please call NPHL Client Services at (402) 559-2440 or toll free at (800) 334-0459.

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