Gardnerella vaginalis

Snapshot

A 26-year-old G0 woman with last menstrual period 5 days ago who presents to her gynecologist for fishy-smelling vaginal discharge. She currently has multiple sexual partners and does not use consistent protection. She also requests to be tested for sexually transmitted diseases. On pelvic exam, she has a thin, malodorous gray vaginal discharge that coats the vaginal wall smoothly. Her vulva is not erythematous or edematous. On wet mount microscopy, clue cells are visualized. She is started on antibiotics.

Introduction

Classification
- Gardnerella vaginalis
  - facultative anaerobic gram-variable pleomorphic rod
  - catalase-negative
  - oxidase-negative
  - causes bacterial vaginosis
  - not a sexually transmitted disease but is associated with sexual activity
Epidemiology
- incidence
  - very common
- demographics
  - women
- risk factors
  - immunosuppression
  - use of antibiotics
  - vaginal douching
  - having multiple sexual partners
  - having unprotected sex
Pathogenesis
- decreased percentage of normal vaginal flora with lactobacillus that produces hydrogen-peroxide
- dominance of G. vaginalis and other anaerobic bacteria
Associated conditions
- HIV infection
- herpes simplex virus type 2
urinary tract infection

Presentation

Symptoms
- often asymptomatic
Physical exam
- thin and gray/white vaginal discharge
- coats the vaginal wall
- vaginal malodor (fishy)
vulva is normal

Studies

Differential

Vulvovaginal candidiasis
- distinguishing factors
  - thick white curd-like vaginal discharge
  - often very itchy with vulvar erythema and edema
Trichomoniasis
- distinguishing factors
  - green vaginal discharge
  - burning sensation with dysuria and dyspareunia
  - postcoital bleeding
vulvar erythema

Treatment

Management approach
- mainstay of treatment is antibiotics
- encourage patients to avoid douching
Medical
- metronidazole or clindamycin
  - indication
all patients

Complications