Bacterial Vaginosis

1. See also
   1. Vaginitis
2. Epidemiology
   1. Accounts for 35-50% of Vaginitis
3. Etiology
   1. Marked reduction in normally predominant lactobacillus
   2. Polymicrobial infection: facultative Anaerobic Bacteria
      1. Peptostreptococcus
      2. Corynebacterium vaginale (Haemophilus vaginalis)
      3. Bacteroides
      4. Mobiluncus species
      5. Mycoplasma hominis
4. Symptoms
   1. Often asymptomatic, or mild
   2. Musty or fishy odor to genitalia or Vaginal Discharge
   3. Profuse thin gray-white, non-clumping Vaginal Discharge
5. Signs: Amsel's Criteria (3 of 4 needed for diagnosis)
   1. Vaginal pH > 4.5 (more alkaline than normal)
      1. See Vaginal pH for differential diagnosis
      2. Test Sensitivity: 77%
      3. Test Specificity: 35%
         1. False positive with Cervical Mucus, Menses or semen
   2. Clue Cells present (on >20% of cells) on saline preparation
      1. Bacteria adhered to vaginal epithelial cells
      2. Test Sensitivity: 53-90%
      3. Test Specificity: 40-100%
      4. Images
         1. 
   3. Positive whiff test (Amine Test)
      1. Test Sensitivity: 67%
      2. Test Specificity: 93%
      3. Volatile amines produce a fishy odor with 10% KOH
      4. Also present with Trichomonal Vaginitis
   4. Discharge characteristics
      1. Thin, non-clumping, gray-white, adherent discharge
6. Labs: New tests
   1. Fem Exam Card 1 (pH and amine) and 2 (proline aminopeptidase)
      1. Rapid, 2 minute test with high sensitivity (91%) but low Specificity
   2. Trimethylamine Card for pH
      1. Rapid test with Low sensitivity, but high Specificity (97%)
7. Management
   1. Non-Pregnant
      1. First-Line: Oral Metronidazole (Flagyl)
         1. Flagyl 500 mg PO bid for 7 days ($5)
      2. Other oral options
         1. Clindamycin 300 mg twice daily for 7 days
      3. Topical options (higher recurrence rate, does not cover Trichomoniasis)
         1. MetroGel (0.75%) 5g intravaginally at bedtime for 5 days ($29)
         2. Clindamycin Cream (2%) 5g intravaginally at bedtime for 7 days ($31)
   2. Pregnancy:
      1. First Trimester
         1. Avoid treatment if possible in first trimester
         2. Clindamycin (Cleocin) 300 mg PO bid for 7 days
         3. Clindamycin Cream 5 grams PV qhs for 7 days
         4. Metronidazole Gel PV bid for 5 days
      2. After First Trimester (prefer after 37 weeks)
         1. Metronidazole (Flagyl) 500 mg twice daily for 7 days
         2. Metronidazole (Flagyl) 250 mg three times daily for 7 days
         3. Clindamycin 300 mg PO bid for 7 days ($28)
   3. Resistant or Refractory Cases
      1. Metronidazole 500 mg PO bid for 14 days (preferred) or
      2. Consider treating sexual partner and patient (not recommended)
         1. Male Urethra may be co-infected
         2. Based on anecdotal reports (evidence lacking)
      3. Other options
         1. Clindamycin at above dose
         2. Povidone-iodine gel OR suppository (Betadine)
            1. Apply vaginally bid for 14 to 28 days ($59)
   4. Recurrent Bacterial Vaginosis
      1. Treat as refractory cases above
      2. Consider maintenance therapy
         1. Induction: Metronidazole gel 0.75% (Metrogel) nightly for 10 days
         2. Maintenance: When wet prep with no clues, pH lower
            1. Metronidazole gel twice weekly for 3-6 months
            2. Treat concurrent Candida if present
               1. Fluconazole 150 mg qWeek
      3. References
         1. Sobel (2006) Am J Obstet Gynecol 194(5): 1283-9
8. Complications
   1. Associated with higher risk of HIV Transmission
      1. Martin (1999) J Infect Dis 180(6):1863-8
   2. Associated with preterm delivery (23-26 weeks)
      1. Hillier (1995) N Engl J Med 333: 1737-42
      2. Hauth (1995) N Engl J Med 333: 1732-6
   3. Early second trimester with better pregnancy outcomes
      1. Reduces preterm birth and late Miscarriage rate
      2. Study used Clindamycin
      3. Ugwumadu (2003) Lancet 361:983-8
9. References
   1. (1998) MMWR Morb Mortal Wkly Rep 47:1-115
   2. Gutman (2005) Obstet Gynecol 105(3): 551-6
   3. Hainer (2011) Am Fam Physician 83(7): 807-15
   4. Larimore (2000) Prim Care 27(1):35-53
   5. Majeroni (1998) Am Fam Physician 57(6):1285-9
   6. Miller (1997) Fam Pract 19(3):33-52