From the Guidelines
Bacterial vaginosis (BV) is characterized by a thin, grayish-white vaginal discharge with a characteristic "fishy" odor, vaginal itching, burning during urination, and mild irritation around the vaginal area, although up to 50% of women with BV may be asymptomatic. The signs of BV can be diagnosed using clinical or Gram-stain criteria, which include a homogeneous, white, noninflammatory discharge that smoothly coats the vaginal walls, the presence of clue cells on microscopic examination, a pH of vaginal fluid >4.5, and a fishy odor of vaginal discharge before or after addition of 10% KOH (i.e., the whiff test) 1. BV occurs when there's an imbalance in the vaginal microbiome, specifically an overgrowth of certain bacteria like Gardnerella vaginalis and a reduction in protective Lactobacillus species, leading to an increase in vaginal pH above 4.5 1. Some key points to consider about BV include:
- The cause of the microbial alteration is not fully understood, but it is associated with having multiple sex partners, douching, and lack of vaginal lactobacilli 1
- Treatment of the male sex partner has not been beneficial in preventing the recurrence of BV 1
- The recommended treatment regimen includes oral or topical metronidazole or clindamycin cream, and follow-up visits are unnecessary if symptoms resolve, but recurrence is not unusual and patients should return for additional treatment if symptoms recur 1 It is essential to seek medical evaluation if BV is suspected, as untreated BV can increase susceptibility to sexually transmitted infections and cause complications during pregnancy, including preterm birth.
From the Research
Signs of Bacterial Vaginosis
The signs of bacterial vaginosis include:
- Abnormal vaginal discharge, which is often described as having a strong, unpleasant odor 2, 3, 4
- Vaginal irritation, itching, or burning 2, 4
- A shift in vaginal contents pH to alkaline values 3
- Positive amino test 3
- Absence of lactic flora 3
- Detection of clue cells in gram-stained smears 3, 4
- Milky discharge 4
- Vaginal pH greater than 4.5 4
- Presence of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis, and Mobiluncus species 5, 6
Diagnosis of Bacterial Vaginosis
Diagnosis of bacterial vaginosis is made using a combination of symptoms, physical examination findings, and office-based or laboratory testing, including:
- Amsel criteria, which require three of four defined criteria to be satisfied 2, 4, 6
- Gram stain, which is the diagnostic standard 2
- Nugent's scoring system, which includes validation of the categories of observable bacteria structures 6
- Molecular tests that detect Gardnerella vaginalis DNA or vaginal fluid sialidase activity 2
- Detection of clue cells on microscopic examination of vaginal fluid 4