| Nugent score | |
|---|---|
| Purpose | diagnose bacterialvaginosis |
TheNugent Score is aGram stain scoring system for vaginal swabs to diagnose bacterialvaginosis (BV). The Nugent score is calculated by assessing for the presence of largeGram-positiverods (Lactobacillus morphotypes; decrease inLactobacillus scored as 0 to 4), small Gram-variable rods (Gardnerella vaginalis morphotypes; scored as 0 to 4), and curved Gram-variable rods (Mobiluncus spp. morphotypes; scored as 0 to 2). A score of 7 to 10 is consistent with bacterial vaginosis without culture. The Nugent Score is now rarely used by physicians due to the time it takes to read the slides and requires the use of a trained microscopist.[1] Bacterial vaginosis diagnosis is done by evaluating the pH, the presences ofLactobacillus spp. versus a mixed flora consisting ofGardnerella vaginalis,Bacteroides spp,Mobiluncus spp, andMycoplasma hominis. The Amsel Criteria for bacterial vaginosis includes pH, evaluating the presence of clue cells, white discharge and an odor of amines after mixing with KOH.[2]
Prior to the development of Nugent score, assessment of bacterial vaginosis was based on culturingG. vaginalis, examining agram stain ofvaginal discharge andgas chromatography.[3]
A score of 0-10 is generated from combining three other scores. The scores are as follows:[3]
At least 10–20 high power (1000× oil immersion) fields are counted and an average determined.
Lactobacillus morphotypes — average per high powered (1000× oil immersion) field. View multiple fields. | Gardnerella /Bacteroides morphotypes — average per high powered (1000× oil immersion) field. View multiple fields. | Curved Gram variable rods — average per high powered (1000× oil immersion) field. View multiple fields (note that this factor is less important — scores of only 0–2 are possible) |
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The scoring system was proposed by Robert P Nugent in 1991. In the study, vaginal swabs were obtained from pregnant women.[3]