Bacterial vaginosis: Difference between revisions

Revision as of 08:20, 6 May 2021

Background

Microbiology

Shift in vaginal flora from Lactobacillus to high bacterial diversity that includes facultative anaerobes
The new flora includes: Gardnerella vaginalis, Prevotella species, Porphyromonas species, Bacteroides species, Peptostreptococcus species, Mycoplasma hominis, Ureaplasma urealyticum, Mobiluncus species, Megasphaera species, Clotridiales species, Fusobacterium species, and Atopobium species

Pathophysiology

The new bacterial flora produce volatile amines, which increases the vaginal pH >4.5 (from the normal range of 4 to 4.5)

Diagnosis

Amsel Criteria

Requires microscopy but not Gram staining
At least three of the following criteria:
- Characteristic vaginal discharge: homogeneous, thin, grayish-white discharge that smoothly coats the vaginal walls
- Elevated pH >4.5
- Clue cells on saline wet mount, which are vaginal epithelial cells studded with adherent coccobacilli
- Positive whiff-amine test, where a fishy odor is detected after a drop of 10% KOH is added to a sample of vaginal discharge

Nugent Criteria

Based on the Gram stain
Considered the gold standard, but is more resource-intensive than wet mount microscopy used for Amsel criteria

Score	Lactobacillus	Gardnerella and Bacteroides	Curved gram-variable bacilli
0	4+	0	0
1	3+	1+	1+ or 2+
2	2+	2+	3+ or 4+
3	1+	3+
4	0	4+

Interpretation is based on total score:
- 0 to 3: normal
- 4 to 6: indeterminate
- 7 to 10: bacterial vaginosis

Others

Culture is not relevant to diagnosis of bacterial vaginosis

Management

Non-Pregnant Woman

First-line:
- Metronidazole 500 mg PO bid for 7 days
- Metronidazole gel 0.75% 5 g (one full applicator) intravaginally once daily for 5 days
- Clindamycin 2% cream 5 g (one full applicator) intravaginally at bedtime for 7 days
Alternatives:
- Clindamycin 300 mg PO bid for 7 days
- Clindamycin ovule (vaingal suppository) 100 mg intravaginally daily for 3 days
- Tinidazole 2 g PO daily for 2 days
- Tinidazole 1 g PO daily for 5 days

Pregnant Women

Metronidazole 500 mg PO bid for 7 days
Metronidazole 250 mg PO tid for 7 days
Clindamycin 300 mg PO bid for 7 days

@@ Line 1: / Line 1: @@
-== Management ==
+== Background ==
+=== Microbiology ===
-* First-line:
-** [[Metronidazole]] 500 mg PO bid for 7 days
+* Shift in vaginal flora from [[Lactobacillus]] to high bacterial diversity that includes facultative anaerobes
-** [[Metronidazole]] gel 0.75% 5 g (one full applicator) intravaginally once daily for 5 days
+* The new flora includes: [[Gardnerella vaginalis]], [[Prevotella species]], [[Porphyromonas species]], [[Bacteroides species]], [[Peptostreptococcus species]], [[Mycoplasma hominis]], [[Ureaplasma urealyticum]], [[Mobiluncus species]], [[Megasphaera species]], [[Clotridiales species]], [[Fusobacterium species]], and [[Atopobium species]]
-** [[Clindamycin]] 2% cream 5 g (one full applicator) intravaginally at bedtime for 7 days
-* Alternatives:
+=== Pathophysiology ===
-** [[Clindamycin]] 300 mg PO bid for 7 days
-** [[Clindamycin]] ovule (vaingal suppository) 100 mg intravaginally daily for 3 days
+* The new bacterial flora produce volatile amines, which increases the vaginal pH >4.5 (from the normal range of 4 to 4.5)
-** [[Tinidazole]] 2 g PO daily for 2 days
-** [[Tinidazole]] 1 g PO daily for 5 days
+== Diagnosis ==
+=== Amsel Criteria ===
+* Requires microscopy but not Gram staining
+* At least three of the following criteria:
+** Characteristic vaginal discharge: homogeneous, thin, grayish-white discharge that smoothly coats the vaginal walls
+** Elevated pH >4.5
+** Clue cells on saline wet mount, which are vaginal epithelial cells studded with adherent coccobacilli
+** Positive whiff-amine test, where a fishy odor is detected after a drop of 10% KOH is added to a sample of vaginal discharge
+=== Nugent Criteria ===
+* Based on the Gram stain
+* Considered the gold standard, but is more resource-intensive than wet mount microscopy used for Amsel criteria
+{| class="wikitable"
+!Score
+!Lactobacillus
+!Gardnerella and Bacteroides
+!Curved gram-variable bacilli
+|-
+|0
+|4+
+|0
+|0
+|-
+|1
+|3+
+|1+
+|1+ or 2+
+|-
+|2
+|2+
+|2+
+|3+ or 4+
+|-
+|3
+|1+
+|3+
+|
+|-
+|4
+|0
+|4+
+|
+|}
+* Interpretation is based on total score:
+** 0 to 3: normal
+** 4 to 6: indeterminate
+** 7 to 10: bacterial vaginosis
+=== Others ===
+* Culture is not relevant to diagnosis of bacterial vaginosis
+==Management==
+=== Non-Pregnant Woman ===
+*First-line:
+**[[Metronidazole]] 500 mg PO bid for 7 days
+**[[Metronidazole]] gel 0.75% 5 g (one full applicator) intravaginally once daily for 5 days
+**[[Clindamycin]] 2% cream 5 g (one full applicator) intravaginally at bedtime for 7 days
+*Alternatives:
+**[[Clindamycin]] 300 mg PO bid for 7 days
+**[[Clindamycin]] ovule (vaingal suppository) 100 mg intravaginally daily for 3 days
+**[[Tinidazole]] 2 g PO daily for 2 days
+**[[Tinidazole]] 1 g PO daily for 5 days
+=== Pregnant Women ===
+* [[Metronidazole]] 500 mg PO bid for 7 days
+* [[Metronidazole]] 250 mg PO tid for 7 days
+* [[Clindamycin]] 300 mg PO bid for 7 days
 [[Category:Gynecologic infections]]