Are Mycoplasma genitalium Symptoms Similar to Bacterial Vaginosis?
No, Mycoplasma genitalium and bacterial vaginosis present with distinctly different clinical features—M. genitalium causes cervicitis with mucopurulent discharge and cervical bleeding, while BV causes a homogeneous white discharge with fishy odor but no inflammation. 1, 2
Key Clinical Distinctions
Mycoplasma genitalium Presentation
- M. genitalium causes mucopurulent cervicitis characterized by purulent endocervical discharge and sustained endocervical bleeding easily induced by gentle swabbing through the cervical os 1
- Women with M. genitalium may complain of abnormal vaginal discharge and intermenstrual vaginal bleeding, particularly after sexual intercourse 1
- M. genitalium is strongly associated with cervicitis and endometritis, not with bacterial vaginosis 2
- The organism displays clinical features similar to C. trachomatis and N. gonorrhoeae, behaving as a classic sexually transmitted pathogen 3
Bacterial Vaginosis Presentation
- BV produces a homogeneous, white, non-inflammatory discharge that smoothly coats the vaginal walls—this is fundamentally different from the purulent discharge of M. genitalium 1, 4
- The hallmark of BV is a fishy odor (especially after KOH application), which is not characteristic of M. genitalium infection 1, 4
- BV is not associated with cervical inflammation or bleeding—it represents vaginal dysbiosis without inflammatory response 1, 4
- Up to 50% of women with BV are completely asymptomatic, whereas M. genitalium more commonly causes symptomatic cervicitis 4
Critical Diagnostic Differences
Physical Examination Findings
- M. genitalium: Look for mucopurulent endocervical exudate, cervical friability with contact bleeding, and leukorrhea (>10 WBC per high-power field) 1
- BV: Look for thin, homogeneous discharge adherent to vaginal walls, clue cells on microscopy, vaginal pH >4.5, and positive whiff test 1, 4
Laboratory Distinctions
- M. genitalium requires nucleic acid amplification testing (NAAT) for diagnosis, as it cannot be cultured reliably 5, 2
- BV is diagnosed clinically using Amsel criteria (3 of 4 required) or Gram stain showing loss of lactobacilli and overgrowth of anaerobes 1, 4
The Relationship Between M. genitalium and BV
Association vs. Causation
- Research shows M. genitalium is NOT a cause of bacterial vaginosis 2
- However, women with BV have nearly twice the odds of concurrent M. genitalium infection (OR = 1.97) compared to women without BV 6
- This association likely reflects shared risk factors (multiple sexual partners, young age) rather than one condition causing the other 3, 6
Clinical Implications
- When evaluating cervicitis, the CDC guidelines recommend testing for both M. genitalium (if available) and assessing for BV, as they can coexist but represent different pathologic processes 1
- The presence of BV does not explain cervicitis symptoms—if a woman has both BV and cervicitis, M. genitalium or other cervical pathogens (C. trachomatis, N. gonorrhoeae) should be suspected 1, 2
Common Pitfalls to Avoid
- Do not assume vaginal discharge with odor is always BV—if there is cervical inflammation, bleeding, or mucopus, test for cervical pathogens including M. genitalium 1
- Do not treat M. genitalium with metronidazole—this is the treatment for BV but is ineffective against M. genitalium, which requires macrolides (azithromycin) 5, 2
- Do not overlook concurrent infections—women presenting with symptoms may have both BV and M. genitalium, requiring different treatment approaches 6
- Remember that standardized diagnostic tests for M. genitalium are not commercially available in all settings, which may limit your ability to definitively diagnose this pathogen 1