87591

Infectious agent detection by nucleic acid (DNA or RNA); Neisseria gonorrhoeae, amplified probe technique

CPT code 87591 refers to a laboratory diagnostic procedure for detecting Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea. This specific code identifies the use of an amplified nucleic acid probe technique, commonly referred to as a Nucleic Acid Amplification Test (NAAT). Unlike traditional culture methods or direct probe techniques (which do not involve an amplification step), NAATs utilize biochemical processes like Polymerase Chain Reaction (PCR), Transcription-Mediated Amplification (TMA), or Strand Displacement Amplification (SDA) to exponentially increase the number of target DNA or RNA sequences present in a clinical specimen. This high level of sensitivity allows for the detection of very small amounts of the organism, making it the preferred method for screening both symptomatic and asymptomatic patients. The procedure can be performed on a variety of specimen types, including endocervical swabs, vaginal swabs, male urethral swabs, and oropharyngeal or rectal swabs. One of the most significant advantages of code 87591 is its compatibility with non-invasive first-catch urine samples in both men and women. The process involves multiple phases: specimen collection and transport in specialized media, extraction of nucleic acids from the sample, the amplification of specific target sequences unique to the N. gonorrhoeae genome, and the subsequent detection of the amplified products using fluorescent signals or other markers. The result is typically reported qualitatively as 'detected' or 'not detected.' Because NAAT does not require live organisms, it is highly robust but does not provide the antimicrobial susceptibility profile that a traditional culture (CPT 87081) would offer.

Clinical Indications

  • Routine screening for sexually transmitted infections (STIs) in sexually active individuals under 25 years of age.
  • Evaluation of symptoms such as dysuria, urethral discharge, or vaginal discharge.
  • Assessment of patients with pelvic inflammatory disease (PID) or cervicitis.
  • Screening of pregnant individuals for gonococcal infection to prevent neonatal complications.
  • Evaluation of patients reporting known or suspected sexual contact with a partner who has tested positive for gonorrhea.
  • Investigation of proctitis or pharyngitis in individuals with a history of receptive anal or oral exposure.
  • Monitoring and follow-up in specific high-risk populations, including individuals with multiple partners or a history of STIs.
  • Test of cure in pregnant women three to four weeks after treatment completion.

Procedure Steps

  1. Collection of clinical specimen using site-specific swabs (vagina, cervix, urethra, rectum, or throat) or a sterile container for first-catch urine.
  2. Transfer of the specimen into the appropriate transport medium to stabilize nucleic acids and prevent degradation.
  3. Lysis of the specimen in the laboratory to release genetic material (DNA or RNA) from the bacterial cells.
  4. Purification and extraction of the nucleic acids from the clinical matrix to remove inhibitors that could interfere with the reaction.
  5. Preparation of the reaction mixture containing primers specific to N. gonorrhoeae, nucleotides, and amplification enzymes (e.g., DNA polymerase).
  6. Initiation of the amplification cycle (e.g., thermal cycling for PCR) to replicate the target genetic sequence.
  7. Detection of the amplified products using labeled probes that emit a signal (such as fluorescence) when they bind to the target sequence.
  8. Analysis of signal data against internal controls to ensure the validity of the run.
  9. Interpretation and reporting of the final qualitative result.

Coding Guidelines

  • Report 87591 for amplified probe techniques; do not use 87590 for direct probe techniques (non-amplified) or 87592 for quantification.
  • If testing for both Chlamydia trachomatis and Neisseria gonorrhoeae using NAAT, report 87591 in addition to 87491.
  • Do not report 87591 if the test is part of a larger multiplex panel for multiple organisms (e.g., 87801) unless specifically directed by the code descriptor.
  • Ensure the correct anatomical source is documented, as some payers may have specific coverage requirements for extragenital (rectal or pharyngeal) testing.
  • Modifiers may be required if the test is repeated on the same day for different anatomical sites, though usually, one code covers the methodology regardless of the number of sites if processed as a single test.
  • Laboratory must be CLIA-certified to perform high or moderate complexity testing depending on the specific platform used.

Associated ICD-10 Codes