Bacterial Vaginosis

Definition:

• Bacterial vaginosis (BV) is a common vaginal condition caused by an imbalance in the vaginal microbiota, leading to a decrease in lactobacilli and an overgrowth of other types of bacteria.

Epidemiology:

• It’s the most common cause of vaginal discharge in women of childbearing age.

Etiology:

• Not completely understood but is associated with a shift from a Lactobacillus-dominated flora to a more diverse microbial profile.
• Factors that may contribute include multiple or new sexual partners, douching, and changes in vaginal pH.

Clinical Features:

• Many women are asymptomatic.
• Symptomatic women may experience a thin, grey, homogeneous vaginal discharge.
• A “fishy” odor, especially after sexual intercourse or during menstruation.
• Itching and irritation are less common.

Diagnosis:

• Clinical diagnosis based on Amsel’s criteria (at least three of the following):
  1. Homogeneous discharge.
  2. pH of vaginal fluid >4.5.
  3. Positive whiff test (fishy odor with 10% KOH).
  4. Clue cells (vaginal epithelial cells coated with bacteria) on microscopic examination.
• Nugent score from a Gram-stained slide can also be used.

Treatment:

• Metronidazole or clindamycin, either orally or vaginally.
• Treatment of sexual partners is not necessary as BV is not considered an STI.

Complications:

• Associated with an increased risk of STI acquisition.
• In pregnant women, BV can be associated with adverse outcomes like preterm birth.