The Aetiology, Diagnosis, and Management of Vaginal Discharge Syndrome

PATHCHAT Edition No. 66
February 2020
Please contact your local Ampath pathologist for more information.

Authors:

• Dr. Chanel Kingsburgh (Clinical Microbiologist)
• Dr. Kathy-Anne Strydom (Clinical Microbiologist)

Introduction

✅ What Is Vaginal Discharge Syndrome?

• Vaginal discharge syndrome may be secondary to vulvovaginitis or cervicitis.
• Most women will experience at least one episode in their lifetime.
• 70–90% of vaginitis cases are due to infectious causes:
  • Bacterial vaginosis (40–50%).
  • Vulvovaginal candidiasis (20–25%).
  • Trichomoniasis (15–20%).
• Non-infectious causes (~5–10%) include:
  • Atrophic vaginitis.
  • Desquamative inflammatory vaginitis.
  • Foreign bodies, irritants, allergens.

📌 Cervicitis, often due to sexually transmitted infections (STIs), may also present with vaginal discharge.

Causes of Vaginal Discharge

✅ Common Conditions & Diagnostic Features

✔ Normal Vaginal Secretions:

• Odourless discharge, no pruritus or inflammation.
• Squamous epithelial cells, rare leukocytes, Lactobacilli predominant.
• pH 4.0–4.5, negative whiff test.

✔ Bacterial Vaginosis (BV):

• Altered vaginal microbiota (loss of Lactobacilli, overgrowth of anaerobes).
• Thin, homogenous, grey, fishy-smelling discharge.
• Clue cells on microscopy, few or no leukocytes.
• pH >4.5, positive whiff test.

✔ Vulvovaginal Candidiasis (VVC):

• Candida overgrowth (C. albicans or non-albicans species).
• Thick, white, cottage cheese-like discharge, vulvar pruritus.
• Budding yeasts/mycelia on saline wet mount in ~70% of cases.
• pH 4.0–4.5, negative whiff test.

✔ Trichomoniasis:

• Trichomonas vaginalis (sexually transmitted).
• Purulent discharge, vulvar irritation, dysuria, dyspareunia.
• Motile flagellated trichomonads on wet mount in ~60% of cases.
• pH >4.5, often positive whiff test.

✔ Desquamative Inflammatory Vaginitis:

• Uncertain cause, presents with purulent discharge, dysuria, dyspareunia.
• Numerous leukocytes, immature parabasal cells.
• pH >4.5, negative whiff test.

✔ Oestrogen Deficiency (Atrophic Vaginitis):

• Vaginal dryness, irritation, dyspareunia, discharge.
• Immature parabasal cells ± leukocytes.
• pH >4.5, negative whiff test.

✔ Cervicitis (Infectious):

• Caused by Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium.
• Purulent discharge, dysuria, lower abdominal pain, dyspareunia.
• Numerous leukocytes, mature vaginal cells.
• May have elevated pH, negative whiff test.

✔ Cervicitis (Non-Infectious):

• Mechanical or chemical irritation.
• Purulent discharge, ± post-coital bleeding.
• Numerous leukocytes, mature vaginal cells.
• May have elevated pH, negative whiff test.

📌 STIs such as N. gonorrhoeae, C. trachomatis, and M. genitalium can cause cervicitis and must be excluded in symptomatic patients.

Diagnosis of Vaginal Discharge Syndrome

✅ Recommended Diagnostic Approach:

1. History & Physical Examination:
   • Assess symptoms, sexual history, prior infections, risk factors.
2. Point-of-Care Testing:
   • Vaginal pH measurement.
   • Saline/KOH wet mount microscopy.
   • Whiff test (fishy odour when KOH added).
3. Amsel’s Criteria for Bacterial Vaginosis (Requires ≥3 of the following):
   • Homogeneous, thin, grey vaginal discharge.
   • Vaginal pH >4.5.
   • Positive whiff test.
   • Clue cells on wet mount.
4. Laboratory Tests:
   • Gram stain (Nugent score for BV).
   • Culture (Candida species, N. gonorrhoeae).
   • PCR for T. vaginalis, C. trachomatis, M. genitalium.

📌 Molecular-based PCR testing is the gold standard for detecting T. vaginalis and STIs.

Management of Vaginal Discharge Syndrome

✅ Treatment Recommendations

✔ Bacterial Vaginosis:

• Metronidazole 400 mg PO bid × 7 days OR
• Metronidazole vaginal gel × 5 days OR
• 2% clindamycin vaginal cream × 7 days (preferred in pregnancy).
• Recurrent BV: Metronidazole gel twice weekly for 4–6 months.

✔ Vulvovaginal Candidiasis:

• Fluconazole 150 mg PO single dose OR topical azole therapy.
• Pregnancy: Topical azole for 7 days.
• Recurrent VVC: Fluconazole 150 mg PO every 72 hrs × 3 doses, then weekly for 6 months.

✔ Trichomoniasis:

• Metronidazole 400 mg PO bid × 7 days.
• Pregnancy: Same as non-pregnant.
• Recurrent cases: Metronidazole 2 g PO daily × 7 days.

✔ Cervicitis (STI-Related):

• Ceftriaxone 250 mg IM + azithromycin 1 g PO single dose (for N. gonorrhoeae, C. trachomatis).
• M. genitalium: Azithromycin 500 mg PO day 1, then 250 mg PO days 2–5 OR
• Moxifloxacin 400 mg PO daily × 10–14 days (for macrolide-resistant cases).

📌 Syndromic management is used in South Africa but can lead to overtreatment—diagnostic testing improves targeted therapy.

Key Takeaways for Clinicians

✅ Bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis are the most common causes of vaginal discharge.
✅ STIs (gonorrhoea, chlamydia, M. genitalium) should be considered in cervicitis.
✅ Point-of-care tests (pH, whiff test, microscopy) aid rapid diagnosis, but PCR remains the gold standard for STIs.
✅ Syndromic management is widely used but may lead to overtreatment or misdiagnosis.
✅ Aetiological diagnosis enables targeted therapy, improves treatment compliance, and reduces recurrence.

📌 Accurate diagnosis and appropriate treatment improve patient outcomes and prevent complications.