Bacterial Vaginosis: Sensitivity and Specificity

Introduction: None written.

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Tags: Gynecologic Infection Tag this Diagnosis.

The sensitivity and specificity of findings for Bacterial Vaginosis are listed below. See the left navigation bar to change the display.

Sensitive and Specific Findings

Amsel Criteria

91%

99%

3/4:

thin, white, homogeneous discharge

clue cells

pH > 4.5

+ Whiff test

for Nugent score 7-10

Study: J Clin Microbiol. 2005 Mar;43(3):1304-8. PMID: 15750100

BVBlue Point-of-Care Test

88%

95%

This is a test for sialidase activity.

Study: J Clin Microbiol. 2005 Mar;43(3):1304-8. PMID: 15750100

Specific Findings

Whiff Test

6.7%

85.9%

Adding 10% KOH to the vaginal discharge yields a fishy odor

(NOT diagnostic!!)

Study: Infect Dis Obstet Gynecol. 2001;9(2):105-11. PMID: 11495550

Sensitive Findings

Vaginal pH

96%

78%

pH > 4.5

Study: The Nugent method is a standardized point scoring system (scores from 0 to 10) based on the presence of three bacterial morphotypes: large gram-positive rods (Lactobacillus spp.), small gram-negative or gram-variable coccobacilli (Gardnerella and anaerobic spp.), and curved gram-variable rods (Mobiluncus spp.) (16). A Nugent score (NS) of 0 to 3 is classified as the presence of normal flora, an NS of 4 to 6 is classified as the presence of an intermediate increase in flora (intermediate flora), and an NS of 7 to 10 is classified as BV.

Negative Findings

Whiff Test

6.7%

85.9%

Adding 10% KOH to the vaginal discharge yields a fishy odor

(NOT diagnostic!!)

Study: Infect Dis Obstet Gynecol. 2001;9(2):105-11. PMID: 11495550

Poorly Diagnostic Findings

Clue Cells

53.3%

84.2%

on vaginal wet mount: >20%

Another study evaluating for "clue cells present" gave sens=96%, spec=99%

Study: Infect Dis Obstet Gynecol. 2001;9(2):105-11. PMID: 11495550

alt: J Clin Microbiol. 2005 Mar;43(3):1304-8. PMID: 15750100

Clinical diagnosis

80.8%

70%

The clinical examination included a speculum examination for observation of mucopurulent cervicitis and evaluation of secretions for color, viscosity, and homogeneity. Vaginal specimens were collected for wet-prep microscopy (normal saline and 10% potassium hydroxide slides), whiff (amines) test using 10% potassium hydroxide added to the vaginal secretions, and determination of vaginal secretion pH (Phenazine Paper, Decon Laboratories, Inc., King of Prussia, PA).

Study: Obstet Gynecol. 2009 Jan;113(1):89-95. PMID: 19104364

Findings With Unspecified Accuracy

Nugent Criteria

No accuracy specified.

on Gram stain, Gardnerella and/or Mobiluncus predominate with few or no Lactobacilli

The Nugent method is a standardized point scoring system (scores from 0 to 10) based on the presence of three bacterial morphotypes: large gram-positive rods (Lactobacillus spp.), small gram-negative or gram-variable coccobacilli (Gardnerella and anaerobic spp.), and curved gram-variable rods (Mobiluncus spp.) (16). A Nugent score (NS) of 0 to 3 is classified as the presence of normal flora, an NS of 4 to 6 is classified as the presence of an intermediate increase in flora (intermediate flora), and an NS of 7 to 10 is classified as BV.

Study: J Clin Microbiol. 2005 Mar;43(3):1304-8. PMID: 15750100