Bacterial Vaginosis

Question 1

What is Bacterial Vaginosis (BV) caused by and what does it lead to?

Answer 1

Bacterial vaginosis (BV) describes an overgrowth of predominately anaerobic organisms such as Gardnerella vaginalis.

This leads to a consequent fall in lactic acid producing aerobic lactobacilli resulting in a raised vaginal pH.

Question 2

Who is BV almost exclusively seen in?

Answer 2

Whilst BV is not a sexually transmitted infection it is seen almost exclusively in sexually active women.

Question 3

What are the features of BV?

Answer 3

Vaginal discharge: ‘fishy’, offensive

Asymptomatic in 50%

Question 4

What is Amsel’s criteria for diagnosis of BV?

Answer 4

3 of the following 4 points should be present:

1. thin, white homogenous discharge
2. clue cells on microscopy: stippled vaginal epithelial cells
3. vaginal pH > 4.5
4. positive whiff test (addition of potassium hydroxide results in fishy odour)

Question 5

What are the 2 management options for BV?

Answer 5

1. Oral metronidazole for 5-7days

2. the BNF suggests topical metronidazole or topical clindamycin as alternatives

Question 6

What are the differences between bacterial vaginosis and Trichomonas

Answer 6

BV presents with thin, white discharge
Trichomonas presents with frothy, yellow-green discharge

BV: Microscopy - clue cells

Trichomonas: Vulvovaginitis; strawberry cervix; wet mount: motile trophozoites

Question 7

What are complications of BV in pregnancy?

Answer 7

Bacterial vaginosis in pregnancy results in an increased risk of preterm labour, low birth weight and chorioamnionitis (bacteria infects the chorion and amnion (the membranes that surround the fetus) and the amniotic fluid (in which the fetus floats). This can lead to infections in both the mother and fetus), late miscarriage

Question 8

What are the guidelines for management of BV in pregnancy?

Answer 8

it was previously taught that oral metronidazole should be avoided in the first trimester and topical clindamycin used instead. Recent guidelines however recommend that oral metronidazole is used throughout pregnancy. The BNF still advises against the use of high dose metronidazole regimes

Question 9

What are clue cells?

Answer 9

Epithelial cells develop a stippled appearance due to being covered with bacteria

Question 10

What is the initial cure rate of BV with oral metronidazole?

Answer 10

70-80% initial cure rate

Question 11

What is the relapse rate of BV after treatment?

Answer 11

relapse rate > 50% within 3mths