Related Subjects:
|Treponema
|Bejel (Endemic syphilis)
|Pinta
|Yaws (Frambesia)
|Syphilis
|Non gonococcal urethritis
|Gonococcal urethritis
|Lymphogranuloma Venereum (LGV)
|Chancroid
|Donovanosis
|Haemophilus ducreyi
|Trichomoniasis Vaginalis
|Gardnerella vaginalis
📖 About
- Gardnerella vaginalis is the primary bacterium associated with bacterial vaginosis (BV), one of the most common vaginal infections in women of reproductive age.
- BV is not a classic STI but is linked with sexual activity and disruption of the normal vaginal flora.
🔬 Characteristics
- Gram-variable coccobacillus (appears Gram-positive or Gram-negative).
- Facultative anaerobe, grows on enriched/complex media.
- Often found with other anaerobes (e.g., Mobiluncus, Prevotella) in BV → polymicrobial infection.
⚔️ Virulence Factors
- Produces volatile amines → classic “fishy odor,” especially after sex (positive “whiff test”).
- Disrupts normal Lactobacillus dominance in the vagina, raising pH.
- Forms biofilms on epithelial cells, aiding persistence and recurrence.
🌍 Source & Risk Factors
- Part of normal vaginal flora in some women.
- Overgrowth triggered by:
- Use of IUDs
- Antibiotic use disrupting Lactobacillus
- New/multiple sexual partners
- Douching or use of perfumed hygiene products
🩺 Clinical Features
- Discharge: Thin, grey-white, homogeneous discharge coating vaginal walls.
- Smell: Strong fishy odor (↑ after intercourse due to alkaline semen).
- Irritation: Mild itching or discomfort; dysuria is uncommon.
🔍 Investigations (Amsel’s Criteria – need ≥3/4)
- Thin, homogeneous discharge.
- Vaginal pH > 4.5.
- Positive “whiff test” (fishy odor when 10% KOH added to discharge).
- “Clue cells” on microscopy (epithelial cells studded with bacteria).
💊 Management
- Treat if symptomatic or before gynaecological procedures (e.g., IUD insertion, pregnancy-related concerns).
- Antibiotics:
- Metronidazole 400–500 mg PO BD × 5–7 days (or topical gel).
- Clindamycin cream intravaginally at night for 7 days.
- Avoid bubble baths, perfumed soaps, and douching.
- Sexual partners usually do not need treatment.
- ⚠️ High recurrence rates (up to 50% within 6–12 months).
📌 Key Associations
- Increased risk of preterm labour and postpartum endometritis.
- Increased susceptibility to HIV and other STIs.
