The Nugent scoring system for Gram-stained vaginal smears is used to diagnose which infection?

The Nugent scoring system for Gram-stained vaginal smears is used to diagnose which infection?

• A. Trichomonas vaginalis infection
• B. Bacterial Vaginosis
• C. Candidiasis
• D. Vulvovaginal atrophy

Answer: (B)

Nugent scoring on Gram-stained vaginal smears measures the balance of vaginal flora to determine if a bacterial vaginosis–type imbalance is present. It evaluates three bacterial morphotypes: lactobacilli (large Gram-positive rods) that normally dominate, BV-associated bacteria such as Gardnerella and Prevotella (small Gram-variable rods), and Mobiluncus species (curved rods). Each morphotype is scored 0 to 4 based on how abundant it is, and the three scores are added to yield a total from 0 to 10. A low total (0–3) indicates normal flora rich in lactobacilli; a mid-range total (4–6) is intermediate; a high total (7–10) supports bacterial vaginosis, reflecting a shift away from lactobacilli toward anaerobic bacteria. This approach is specific to BV diagnosis rather than other infections that have different diagnostic findings: trichomoniasis is typically identified by motile Giardia-like parasites on a wet mount or NAAT; candidiasis is diagnosed by budding yeasts and pseudohyphae on KOH or Gram stain; vulvovaginal atrophy involves epithelial changes rather than a characteristic Gram-stain flora pattern.

Nugent scoring on Gram-stained vaginal smears measures the balance of vaginal flora to determine if a bacterial vaginosis–type imbalance is present. It evaluates three bacterial morphotypes: lactobacilli (large Gram-positive rods) that normally dominate, BV-associated bacteria such as Gardnerella and Prevotella (small Gram-variable rods), and Mobiluncus species (curved rods). Each morphotype is scored 0 to 4 based on how abundant it is, and the three scores are added to yield a total from 0 to 10. A low total (0–3) indicates normal flora rich in lactobacilli; a mid-range total (4–6) is intermediate; a high total (7–10) supports bacterial vaginosis, reflecting a shift away from lactobacilli toward anaerobic bacteria. This approach is specific to BV diagnosis rather than other infections that have different diagnostic findings: trichomoniasis is typically identified by motile Giardia-like parasites on a wet mount or NAAT; candidiasis is diagnosed by budding yeasts and pseudohyphae on KOH or Gram stain; vulvovaginal atrophy involves epithelial changes rather than a characteristic Gram-stain flora pattern.