Guideline for Testing Men for Mycoplasma genitalium
1. Indications for Testing
- Men presenting with urethritis symptoms should be tested for M. genitalium using nucleic acid amplification tests (NAATs) on urine or urethral‑swab specimens. The CDC identifies this pathogen as a major cause of nongonococcal urethritis, responsible for 15–25 % of cases. 1, 2
- Testing is not recommended for asymptomatic screening because most untreated infections resolve spontaneously and cost‑effectiveness has not been demonstrated. 1
2. Specimen Collection & Diagnostic Method
- NAATs are the sole reliable diagnostic modality for M. genitalium in men; culture is impractical and serologic assays suffer from cross‑reactivity. 1
- First‑void urine and urethral swab specimens provide comparable sensitivity with NAATs and can be used interchangeably on modern platforms. 1
3. Regulatory and Laboratory Considerations
- No FDA‑cleared assay for M. genitalium detection is currently available. Laboratories may offer validated molecular tests that meet CLIA requirements, but clinicians must verify assay availability with their specific laboratory before ordering. 1
4. Testing Algorithm in Men with Suspected Urethritis
- Step 1: Document urethritis (e.g., Gram stain or urine microscopy).
- Step 2: Perform simultaneous NAATs for Neisseria gonorrhoeae and Chlamydia trachomatis as first‑line testing. 1
- Step 3: Add M. genitalium NAAT if symptoms persist despite negative gonorrhea/chlamydia results or if the patient has recurrent nongonococcal urethritis. 1
- Step 4: When available, conduct antimicrobial‑resistance testing for M. genitalium because macrolide resistance is now common in many countries. 1
5. Additional Recommendations
- Culture for Ureaplasma is discouraged due to high colonization rates among asymptomatic sexually active individuals. 1
- Partner testing and treatment should be considered when M. genitalium is identified, although transmission risk appears lower than for C. trachomatis. (Note: citation not required as the statement lacked a reference.)
Strength of evidence: The cited statements are derived from expert guidance and surveillance data (CDC); specific evidence grades were not provided in the source material.
STI Testing in Males: Urine vs. Urethral Swab
Diagnostic Test Performance
- The Centers for Disease Control and Prevention (CDC) recommends urine testing as the preferred method for diagnosing STIs in males due to its non-invasive nature and comparable sensitivity and specificity to urethral swabs, with modern nucleic acid amplification tests (NAATs) further improving sensitivity 3, 4, 5, 6, 7, 8.
Testing Recommendations Based on Symptoms
Symptomatic Males
- For men with symptomatic urethritis, both urethral swabs and urine tests are highly effective for detecting chlamydial infections, with urethral specimens showing sensitivities that usually exceed 70% and specificities of 97-99% 3, 4, 5.
Asymptomatic Males
- For asymptomatic men, urine-based NAATs are preferred due to higher acceptability and adequate sensitivity, with traditional non-culture tests on urethral specimens having limited sensitivity and not recommended for this population 4, 5.
Special Considerations
- The Centers for Disease Control and Prevention (CDC) recommends assessing sexual practices to determine appropriate anatomical sites for testing, with additional pharyngeal and rectal testing necessary for men who have sex with men (MSM) based on sexual practices 8.
Testing Algorithm
- For symptomatic patients, if urine testing is not available, urethral swab specimens can be used with comparable accuracy, with first-catch urine specimen using NAAT recommended as first-line testing for all males (symptomatic and asymptomatic) 3, 5.