Bacterial vaginosis is a polymicrobial clinical syndrome .It result from replacement of the normal hydrogen peroxide producing Lactobacillus sp. in the vagina with high concentrations of anaerobic bacteria. Some women experience transient vaginal microbial changes, whereas others experience them for longer intervals of time.Among women presenting for care, bacterial vaginosis  is the most prevalent cause of vaginal discharge or malodor.

Most women with bacterial vaginosis are asymptomatic.Bacterial vaginosis is associated with; 1) Having  multiple male or female partners.  2)A new sex partner. 3)Douching. 4)Having unprotected sex and. 5)Lack of vaginal lactobacilli.Women who have never been sexually active are rarely affected .

 Common anaerobic bacteria associated with bacterial vaginosis

  1. Prevotella sp.
  2. Mobiluncus sp.
  3.  G. vaginalis
  4. Ureaplasma
  5. Mycoplasma and
  6. Numerous fastidious or uncultivated anaerobes

Common  risk factors

  1. Having multiples sexual partners
  2. Complication arising from gynecological surgery such as hysterectomy
  3. Pregnancy complications
  4. Douching

What ares diagnostic Considerations?

Doctor/clinician uses the following clinical criteria for diagnosis.

 Amsel’s Diagnostic Criteria or Gram stain. A Gram stain is considered the gold standard laboratory method for diagnosing Bacterial vaginosis. It is used to determine the relative concentration of lactobacilli eg;

  1. Long Gram-positive rods
  2. Gram-negative
  3. Gram-variable rods
  4.  Cocci (i.e., G. vaginalisPrevotellaPorphyromonas, and peptostreptococcus)  and
  5. Curved Gram-negative rods (i.e., Mobiluncus) characteristic of Bacterial vaginosis.

Clinical criteria require three of the following symptoms or signs:

  1. Homogeneous, thin, white discharge that smoothly coats the vaginal walls.
  2. Clue cells (e.g., vaginal epithelial cells studded with adherent coccobacilli) on microscopic examination.
  3. pH of vaginal fluid more than 4.5  or
  4. A fishy odor of vaginal discharge before or after addition of 10% KOH (i.e., the whiff test).

Lab test that are commonly ordered by doctor

1.)Gram stain:

  • It has 90% sensitivity, highly sensitive & specific.
  • Scoring systems which weight numbers of lactobacilli & numbers of G vaginalis & Mobiluncus. It is simple & objective method.

2.)Wet film (drop of vaginal secretion & drop of saline):

  • Clue cells (epithelial cells covered by coccobacilli, borders are indistinct), no white blood cells.
  • It is the single most sensitive & specific criterion for Bacterial vaginosis , but it is operator dependent. Debris & degenerated cells may be mistaken for clue cells & lactobacilli may adhere to epithelial cells in low numbers

     3.)Whiff test (amine test).

Exposure of bacterial vaginosis related pics
picture of cervix shows inflammation and whitish discharge.
  • Addition of 10% KOH to a sample of vaginal discharge produces fishy odor.
  • It has a positive predictive value of 90% & specificity of 70%
  •  low pH virtually excludes BV. An elevated pH is the most sensitive but least specific as an increase can also associated with menstruation, recent sexual intercourse, or infection with T. vaginalis


4.)Rapid tests:

  • Diamine test: rapid, sensitive & specific
  • Proline aminopeptidase test (Pip Activity test Card)
  • A card test for detection of elevated pH & trimethylamine (FemExam test card)
  • DNA probe based test for high concentration of G. vaginalis (Affirm VP III) may have clinical utility.

5.)Pap smear;

  • It has limited clinical utility because of low sensitivity


  • It is not recommended as a diagnostic tools because it is not specific.

How is Bacterial vaginosis treated?

Treatment is recommended for women with symptoms. Potential benefits to treatment include reduction in the risk for acquiring C. trachomatis, N. gonorrhoeaeT. vaginalis, HIV, and herpes simplex type 2 .

Your doctor may prescribe one of the following medication.

  • Metronidazole 500 mg orally twice a day for 7 days
  • Metronidazole gel 0.75%, one full applicator (5 g) intravaginally, once a day for 5 days
  • Clindamycin cream 2%, one full applicator (5 g) intravaginally at bedtime for 7 days

Other alternative treatment

  • 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 at bedtime for 3 days
Other Management Considerations

All women with Bacterial vaginosis should be tested for HIV and other STIs.


  1. Women should be advised when to return for evaluation if symptoms recur.
  2. Retreatment  is done by using the same recommended regimen in case of persistent or recurrent bacterial vaginosis after the first occurrence.
  3. Monthly oral metronidazole 2 grams administered with fluconazole 150 miligrams. This has also been evaluated as suppressive therapy. The regimen reduced the incidence of bacterial vaginosis and promoting colonization with normal vaginal flora .
  4. Is it important to treat of Sex Partners? Data from clinical trials does not support routine treatment of sex partner and hence not  recommended.

Special Considerations

Allergy, Intolerance, or Adverse Reactions

  • Intravaginal clindamycin cream is preferred in case of allergy or intolerance to metronidazole or tinidazole
  • Intravaginal metronidazole gel can be considered for women who are not allergic to metronidazole but do not tolerate oral metronidazol

Avoid alcohol consumption during treatment with nitroimidazoles. This help to avoid the possibility of a disulfiram-like reaction. Abstinence from alcohol use should continue for 24 hours after completion of metronidazole or 72 hours after completion of tinidazole

In pregnancy

  1. Treatment is recommended for all symptomatic pregnant women.
  2. Studies have shown that metronidazole 250mg/500mg tabs or metronidazole gel are effective and safe during pregnancy.
  3. Clindamycin oral/cream have cure rate of 85% and equally save in pregnacy as per recent stadies.
  4. Although metronidazole crosses the placenta, no evidence of teratogenicity or mutagenic effects in infants has been found in multiple cross-sectional and cohort studies of pregnant women. Data suggest that metronidazole therapy poses low risk in pregnancy.

In HIV Infection

Bacterial vaginosis appears to recur with higher frequency in women who have HIV infection. Women with HIV who have BV should receive the same treatment regimen as those who do not have HIV infection.

What Are the Possible Complications of Bacterial Vaginosis?

When left untreated, bacterial vaginosis can cause serious complications and health risks. These include:

  • Pregnancy complications: Pregnant women with BV are more likely to have an early delivery or low birth weight baby. They also have a greater chance of developing another type of infection after delivery.
  • Sexually transmitted infections: BV increases your risk of getting sexually transmitted infections, including the herpes simplex virus, chlamydia, and HIV.
  • Pelvic inflammatory disease: In some cases, BV may lead to pelvic inflammatory disease, an infection of the reproductive organs in women. This condition can increase the risk of infertility.
  • Infections after surgery: BV puts you at a higher risk for infections after surgeries affecting the reproductive system. These include hysterectomies, abortions, and cesarean deliveries.



Doc bob

Am Robert Mathenge, a healthcare provider in Nakuru county. i love this profession as it gives me chance to serve my call, interacting with people from various social backgrounds makes me feel good.

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