Sign in →

Test Code GCRNA Neisseria gonorrhoeae by Nucleic Acid Amplification (HOLOGIC)

Reporting Name

Neisseria gonorrhoeae Amplified RNA

Useful For

Detection of Neisseria gonorrhoeae

Method Name

Transcription Mediated Amplification

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Varies


Necessary Information


Specimen source is required.



Specimen Required


Submit only 1 of the following specimens:

 

Swab specimen must be collected using an Aptima Collection Unisex Swab (T583), or Aptima Collection Multitest Swab (T584, formerly called Aptima Vaginal Swab Specimen Collection Kit). These swabs are contained in the Aptima Collection Kit.

 

Supplies: Swab, Aptima Male/Female Collection (T583)

Specimen Type: Endocervix

Container/Tube: Aptima Collection Unisex Swab (T583)

Specimen Volume: Swab

Collection Instructions:

1. Use cleaning swab (white shaft) to remove excess mucus from endocervix and discard.

2. Insert second swab (blue shaft) 1 to 1.5 cm into endocervical canal, and rotate swab gently for 30 seconds. Avoid touching vaginal wall when removing swab.

3. Place second swab into transport tube provided in collection kit. Snap off swab at score line so swab fits into closed tube.

4. Cap tube securely, and label tube with patient's entire name, and date and time of collection.

5. Transport and store swab container at 2 to 30° C (refrigerate is preferred temperature) within 60 days of collection. If longer storage is needed, freeze at -20 to -70° C for 12 months.

 

Supplies: Swab, Aptima Multitest Swab Specimen Collection Kit (T584)

Specimen Type: Vaginal

Container/Tube: Aptima Collection Multitest Swab (T584)

Specimen Volume: Swab

Collection Instructions:

1. Insert swab (pink shaft) about 5 cm past introitus and rotate gently for 30 seconds.

2. Place swab into transport tube provided in collection kit. Snap off swab at score line so swab fits into closed tube.

3. Cap tube securely, and label tube with patient's entire name, and date and time of collection.

4. Transport and store swab container at 2 to 30° C (refrigerate is preferred temperature) within 60 days of collection. If longer storage is needed, freeze at -20 to -70° C for 12 months.

 

Supplies: Swab, Aptima Male/Female Collection (T583)

Specimen Type: Urethra (Males Only)

Container/Tube: Aptima Collection Unisex Swab (T583)

Specimen Volume: Swab

Collection Instructions:

1. Patient should not have urinated for at least 1 hour prior to collection.

2. With a rotating movement, insert swab (blue shaft) 2 to 4 cm into urethra.

3. Once inserted, rotate swab gently at least 1 full rotation using sufficient pressure to ensure swab comes into contact with all urethral surfaces. Allow swab to remain inserted for 2 to 3 seconds.

4. Place swab in transport tube provided in collection kit. Snap off swab at score line so swab fits into closed tube.

5. Cap tube securely, and label tube with patient's entire name, and date and time of collection.

6. Transport and store swab container at 2 to 30° C (refrigerate is preferred temperature) within 60 days of collection. If longer storage is needed, freeze at -20 to -70° C for 12 months.

 

Supplies: Aptima Urine Transport Tube (T582)

Specimen Type: Urine (Males and Females)

Container/Tube: Aptima Urine Specimen Transport Tube (T582)

Specimen Volume: 15-20 mL

Collection Instructions:

1. Patient should not have urinated for at least 1 hour prior to specimen collection.

2. Patient should collect first portion of random voided urine (first part of stream) into a sterile, plastic, preservative-free container.

3. Transfer 2 mL of urine into the urine specimen transport tube using the disposable pipette provided within 24 hours of collection. The correct volume of urine has been added when the fluid level is between the black fill lines on the urine transport tube. Place the labels on the transport tube so the black fill lines are still visible for volume confirmation at Mayo Medical Laboratories.

4. Transport and store urine specimen transport container at 2 to 30° C (refrigerate is preferred temperature) within 30 days of collection. If longer storage is needed, freeze at -20 to -70° C for 12 months.

 

Supplies: Aptima Thin Prep Transport Tube (T652)

Specimen Type: ThinPrep Specimen (Endocervix)

Container/Tube: ThinPrep (also called PreservCyt) Collection Kit (T652)

Specimen Volume: 1 mL

Collection Instructions:

1. Aliquot ThinPrep specimen for Chlamydia and/or Neisseria testing before processing for Pap smear. For each specimen, use a new pair of clean gloves.

2. Vortex ThinPrep/PreservCyt vial 3 to 10 seconds. Within 1 minute of vortexing:

a. Transfer 1 mL of specimen into the Aptima Specimen Transfer Tube (T652) using a disposable transfer pipette or a pipette tip containing a filter (aerosol barrier or hydrophobic plug).

b. Process only 1 ThinPrep and transfer tube set at a time.

c. Recap Aptima Specimen Transfer Tube tightly and gently invert 3 times to mix.

3. Label Aptima transfer tube with appropriate label.

4. Use remainder of ThinPrep specimen for Pap testing.

5. Transport and store specimen transfer container at 2 to 30° C (refrigerate is preferred temperature) within 60 days of collection. If longer storage is needed, freeze at -20 to -70° C for 12 months.


Specimen Minimum Volume

Endocervix in PreservCyt: 1mL
Urine: 2 mL
Swabs (Endocervical, Urethral, Vaginal): Entire collection

Specimen Stability Information

Specimen Type Temperature Time
Varies Refrigerated (preferred)
  Ambient 
  Frozen 

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Midstream urine specimen, overfilled or underfilled urine transport tubes, specimen collected into a SurePath device, transport tubes containing a cleaning swab or more than 1 swab

Reference Values

Negative

Day(s) and Time(s) Performed

Monday through Saturday; Varies

CPT Code Information

87591

LOINC Code Information

Test ID Test Order Name Order LOINC Value
GCRNA Neisseria gonorrhoeae Amplified RNA 43305-2

 

Result ID Test Result Name Result LOINC Value
SRC17 SOURCE: 31208-2
34875 Neisseria gonorrhoeae amplified RNA 43305-2

Analytic Time

1 day

Cautions

Care must be taken to avoid cross-contamination during handling of PreservCyt solution liquid Pap specimens. If testing PreservCyt specimens processed with the ThinPrep 2000 processor, it is important to follow procedures to reduce the risk for cross-contamination during Pap processing such as bleaching of the PreservCyt filter cap and changing gloves between each sample. Refer to the ThinPrep 2000 Processor Operator's Manual and the Aptima specimen for more guidance.

 

The performance of endocervical, vaginal, and male urethral swab specimens, male and female urine specimens, and PreservCyt solution liquid Pap specimens has not been evaluated in adolescents less than 16 years of age. The performance of vaginal swab specimens has not been evaluated in pregnant women.

 

This report is intended for use in clinical monitoring or management of patients; it is not intended for use in medico-legal applications.

 

Appropriate specimen collection and handling is necessary for optimal assay performance.

 

Results should be interpreted in conjunction with other laboratory and clinical information.

 

A negative test result does not exclude the possibility of infection. Improper specimen collection, concurrent antibiotic therapy, presence of inhibitors, or low numbers of organisms in the specimen (ie, below the sensitivity of the test) may cause false-negative test results.

 

In low-prevalence populations, positive results must be interpreted carefully as false-positive results may occur more frequently than true-positive results in this setting.

 

In general, this assay should not be used to assess therapeutic success or failure, since nucleic acids from these organisms may persist for 3 weeks or more following antimicrobial therapy.

 

The presence of mucous does not interfere with this assay. However, this test requires endocervical cells, and if excess mucous is not removed prior to collection, adequate numbers of these cells may not be obtained.

 

No interference is expected with swab specimens due to:

-Blood

-Lubricants and spermicides

 

The effects of use of tampons, douching, specimen types other than those listed in Specimen Required, and specimen collection variables have not been determined.

 

Testing of urine specimens with this method is not intended to replace cervical exam and endocervical sampling for diagnosis of urogenital infection; infections may result from other causes or concurrent infections may occur.

 

Testing urine specimens as the sole test for identifying female patients with gonococcal infections may miss some infected individuals.

 

Performance estimates for urine specimens are based on evaluation of urine obtained from the first part of the urine stream; performance on midstream collections has not been determined.

 

This assay has not been shown to cross-react with commensal (nonpathogenic) Neisseria species in the oropharynx.

Method Description

The HOLOGIC APTIMA Combo 2 Assay combines the technologies of target capture, transcription-mediated amplification, and dual kinetic assay. The detection of the rRNA amplification product sequences (amplicon) is achieved using nucleic acid hybridization. Single-stranded chemiluminescent DNA probes are labeled and combine with amplicon to form stable RNA:DNA hybrids. Light emitted from the labeled RNA:DNA hybrids is measured as photon signals in a luminometer.(Package insert: HOLOGIC APTIMA Combo 2 Assay 501798 Rev. 002 2017-03)

Interpretation

A positive result indicates the presence of rRNA of Neisseria gonorrhoeae.

 

A negative result indicates that rRNA for Neisseria gonorrhoeae was not detected in the specimen.

 

The predictive value of an assay depends on the prevalence of the disease in any particular population. In settings with a high prevalence of sexually transmitted disease, positive assay results have a high likelihood of being true-positives. In settings with a low prevalence of sexually transmitted disease, or in any settings in which a patient's clinical signs and symptoms or risk factors are inconsistent with gonococcal or chlamydial urogenital infection, positive results should be carefully assessed and the patient retested by other methods (eg, culture for Neisseria gonorrhoeae), if appropriate.

Specimen Retention Time

7 days

Clinical Information

Gonorrhea is caused by the bacterium Neisseria gonorrhoeae, which is a common sexually transmitted infection (STI).(1,2) Many infections in women are asymptomatic and the true prevalence of gonorrhea is likely much higher than reported. The organism causes genitourinary infections in women and men and may be associated with dysuria and vaginal, urethral, and/or rectal discharge. Potential complications include pelvic inflammatory disease in women and gonococcal epididymitis and prostatitis in men. Gonococcal bacteremia, pharyngitis, and arthritis may also occur. Infection in men is typically associated with symptoms that would prompt clinical evaluation. Given the risk for asymptomatic infection in women, screening is recommended for women at increased risk of infection (e.g., women with previous gonorrhea or other STI, inconsistent condom use, new or multiple sex partners, and women in certain demographic groups, such as those in communities with high STI prevalence).(1,2)

 

Routine bacterial culture was previously considered the gold standard test for diagnosis of Neisseria gonorrhoeae infection. However, organisms are labile in vitro, therefore, precise specimen collection, transportation, and processing conditions are required to maintain organism viability, which is necessary for successful culturing. In comparison, nucleic acid amplification testing (NAAT) provides superior sensitivity and specificity and is now the recommended method for diagnosis in most cases.(2-5) Immunoassays and nonamplification DNA tests are also available for Neisseria gonorrhoeae detection, but these methods are significantly less sensitive and specific than NAAT.(2-5)

 

Improved screening and performance of NAAT testing has resulted in an increased number of accurately diagnosed cases.(2-5) Improved detection rates result from both the increased performance of the assay and the patients' easy acceptance of urine testing. Early identification of infection enables sexual partners to seek testing and treatment as soon as possible and reduces the risk of disease spread. Prompt treatment reduces the risk of complications in women.

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request Form (T244) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/microbiology_test_request_form.pdf).