What is the treatment for Gardnerella vaginalis or bacterial vaginosis?

Treatment of Gardnerella Vaginalis/Bacterial Vaginosis

Metronidazole 500mg orally twice daily for 7 days is the first-line treatment for bacterial vaginosis (BV) caused by Gardnerella vaginalis, with a 95% cure rate. 1

Diagnosis of Bacterial Vaginosis

Before initiating treatment, diagnosis should be confirmed using the Amsel criteria, which requires 3 of the following 4 findings:

• Homogeneous, white, thin discharge that smoothly coats the vaginal walls
• Presence of clue cells on microscopic examination
• Vaginal fluid pH > 4.5
• Fishy odor of vaginal discharge before or after addition of 10% KOH (positive "whiff test") 2, 1

Alternatively, a Gram stain of vaginal smear showing markedly reduced Lactobacillus morphology, predominance of Gardnerella morphotype, and absent or few white blood cells can confirm the diagnosis 3.

Treatment Options

First-line Treatment:

• Metronidazole 500mg orally twice daily for 7 days (95% cure rate) 1

Alternative Regimens:

• Metronidazole gel 0.75% intravaginally once daily for 5 days (95% cure rate) 1, 3
• Clindamycin cream 2% intravaginally at bedtime for 7 days 1
• Tinidazole 2g orally once daily for 2 days or 1g once daily for 5 days 4
• Metronidazole 2g orally in a single dose (84% cure rate) 1

Special Populations

Pregnant Women:

• First trimester: Clindamycin cream is recommended (metronidazole is contraindicated) 1
• Second and third trimesters: Metronidazole oral/gel or clindamycin cream can be used 1
• High-risk pregnant women (previous preterm delivery) with asymptomatic BV should be evaluated for treatment to reduce risk of prematurity 2, 1

HIV-Positive Patients:

• Same treatment regimens as HIV-negative patients 1

Management of Recurrent BV

BV has a high recurrence rate of 50-80% within the first year after treatment 1, 5. For recurrent cases:

1. Extended course of metronidazole 500mg twice daily for 10-14 days 5
2. If ineffective, metronidazole vaginal gel 0.75% for 10 days, followed by twice weekly application for 3-6 months 1, 5

Important Clinical Considerations

• Treatment of male sex partners has not been beneficial in preventing BV recurrence 2
• Patients should avoid alcohol during metronidazole treatment and for 24 hours after completion 1
• Clindamycin creams can weaken latex condoms 1
• Consistent condom use during sexual intercourse may help prevent recurrence 1
• All symptomatic women require treatment 2
• Women undergoing surgical abortion or hysterectomy should be screened and treated for BV to reduce post-operative infectious complications 2

Follow-up

• Return visits only needed if symptoms persist or recur 1
• Pregnant women should have follow-up evaluation one month after treatment completion 1

By following these evidence-based guidelines, clinicians can effectively diagnose and treat bacterial vaginosis, reducing symptoms and potential complications associated with this common condition.