Bacterial Vaginosis (BV)

Background

• Bacterial vaginosis (BV) is a vaginal dysbiosis due to loss of hydrogen peroxide and lactic acid producing lactobacilli and increases in facultative (i.e., Gardnerella vaginalis) and strict anaerobic bacteria (i.e., Prevotella spp., Atopobium vaginae, Megasphaera spp. and others).
• Epidemiological data suggest that BV is sexually transmitted however, it is currently unknown whether BV results from acquisition of a single sexually transmitted pathogen or a polymicrobial consortium of microorganisms.
• BV is often asymptomatic. When present, characteristic symptoms include foul-smelling (fishy) vaginal odor, and thin, gray-white vaginal discharge.
• BV may increase risk for HIV and other sexually transmitted infections, including Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium, herpes simplex virus (HSV) type 2, and human papillomavirus (HPV).
• Patients with BV are also at increased risk for postoperative endometritis after gynecologic surgery, preterm delivery in pregnant patients, and recurrence of BV.
• BV prevalence may increase in individuals initiating copper intrauterine devices.

Evaluation

• Use Amsel clinical criteria or Gram stain with Nugent scoring for the diagnosis of BV (Strong recommendation). Clinical diagnosis requires ≥ 3 of the following 4 Amsel criteria:
  • homogeneous, thin, white or gray discharge coating the vaginal walls
  • presence of at least 20% clue cells per high power field on wet mount microscopy of vaginal discharge
  • vaginal fluid pH > 4.5
  • a fishy odor of vaginal discharge before or after addition of 10% potassium hydroxide (i.e., whiff test)
• Point-of-care testing with the OSOM BVBlue test or Affirm VP III appear accurate for diagnosing BV. Because G. vaginalis is common in asymptomatic individuals, the Affirm VP III test is most useful in symptomatic individuals in conjunction with vaginal pH measurement and presence of amine odor.
• Several commercial diagnostic nucleic acid amplification tests (NAATs) are available for diagnosis of BV in symptomatic individuals using self-collected or clinician-collected vaginal swabs including 2 that are FDA approved, the BD MAX Vaginal Panel and Hologic Aptima BV. Many of these tests are based on detection of specific bacterial nucleic acids with high sensitivity and specificity for BV, specifically Gardnerella vaginalis, Atopobium vaginae, BVAB-2, and Megasphaera spp.
• Despite the availability of BV molecular assays, traditional methods of BV diagnosis, including the Amsel criteria and the Affirm VP III assay, remain useful for the diagnosis of symptomatic BV due to their lower cost and ability to provide a rapid diagnosis.
• Home testing and treatment without an exam:
  • Whenever possible, patients requesting treatment by telephone should be asked to come in for an evaluation, especially patients who have been self-treating with nonprescription antifungal medication and have persistent vaginal symptoms.
  • For patients known to be compliant who have history of confirmed prior episodes and who currently report same symptoms, a course of treatment can be initiated over phone.
• Do not screen for BV in asymptomatic pregnant individuals who are at low risk for preterm delivery.

Management

• Treat symptomatic individuals, including those with HIV and who are pregnant.
  • First line options:
    • metronidazole 500 mg orally twice daily for 7 days or metronidazole gel 0.75% one full applicator (5 g) intravaginally once daily for 5 days or
    • intravaginal clindamycin cream 2% 1 full applicator (5 g) intravaginally once daily at bedtime for 7 days as first-line options.
  • Alternative regimens:
    • secnidazole 2 g oral granules mixed in apple sauce, yogurt, or pudding in a single dose
    • tinidazole 2 g orally once daily for 2 days
    • tinidazole 1 g orally once daily for 5 days
    • clindamycin 300 mg orally twice daily for 7 days
    • clindamycin ovules 100 mg intravaginally once daily at bedtime for 3 days
• Do not use tinidazole or secnidazole during pregnancy.
• Individuals should abstain from sex or use condoms consistently during treatment.
• Routine treatment of sex partners is not recommended.
• Probiotics are not currently recommended for the treatment and prevention of BV due to insufficient evidence.
• Consider treatment of asymptomatic BV before hysterectomy to prevent BV-associated posthysterectomy vaginal-cuff cellulitis.