Bacterial vaginosis

Affects millions of women annually.

Prevalence among women of reproductive age is approximately 30%.

Affects 15-50% of women of reproductive age, and recurrence is common after treatment with an antibiotic.

Bacterial vaginosis represents a disruption of the vaginal microbiome.

Bacterial vaginitis is associated with sexual activity, lack of condom use, sex with a female partners, and douching in reproductive age persons.

After treatment with an antibiotic, 20-75% of women have recurrent bacterial vaginosis within three months.

Bacterial vaginosis has been associated with an increased risk of sexually transmitted infections including HIV, as well as premature birth, and other reproductive health sequelae.

Recurrent bacterial vaginosis leads to negative emotional, sexual and social effects.

Vaginal infections are among the most common medical reasons for which women consult a physician resulting in 5-10 million office visits per year.

A common lower genital tract syndrome defined as a shift from normal hydrogen peroxide-producing lactobacilli two mixed anaerobes.

Caused by destruction of the microbiological environment in the lower genital  tract.

The amine-fishy odor characteristic of bacterial vaginitis mat be transiently pressent when the vaginal microbiota is temporarily distrusted  from menses or recent intercourse.

Only 25-50% of women with bacterial vaginosis report symptoms.

Vaginal infections affect the quality of life of women by causing frustration, anxiety, sexual dysfunction, and vulvovaginal discomfort.

In women, differences are noted in the composition of resident microorganisms soon after birth as well as at prepubertal, postpubertal, and postmenopausal transitions.

The presence and relative abundance of bacterial species in the vagina are affected by hormonal contraception, pregnancy, and menopause.

At puberty, anaerobic and aerobic lactobacilli aid in maintaining vaginal pH.

Bacterial vaginosis is characterized by anaerobic species with predominance over typical lactobacilli.

If the normal microbiota is suppressed, it allows for yeast and other bacteria to grow causing vaginitis, and dramatic shifts in the makeup of the vaginal microbiota can lead to bacterial vaginosis.

Vaginosis and desquamative inflammatory vaginitis are linked to adverse pregnancy outcomes, pelvic inflammatory disease, increased risk of sexually transmitted infections and poor outcome in in vitro fertilization.

Associated with preterm labor with low birth weight, pelvic inflammatory disease, and acquisition of HIV.

Characterized by pruritus, dysuria, fishy odor of the copious, frothy secretions.

The presence of Clue cells, vaginal epithelial cells covered with coccobacillary bacteria seen on wet mount of vaginal discharge.

Many women are asymptomatic but can have a malodorous vaginal discharge.


Bacterial vaginosis is often asymptomatic, can resolve spontaneously, and recurs often with or without treatment.


Pregnant women have a prevalence of bacterial vaginosis that ranges from 5.8-19.3% and is higher in some races and ethnicities.


Bacterial vaginosis during pregnancy is associated with preterm delivery, early miscarriage, postpartum endometritis, and low birth weight.

Women have loss of vaginal lactobacilli and overgrowth of anaerobic and facultative bacteria.

While Gardnerella vaginalis and Mobiluncus curtisii have been implicated in bacterial vaginosis they are not specific for the disease.

Cultures of vaginal fluid not useful in diagnosis.

No single bacterium causes the disease.

May be a polymicrobial disease with metabolic interdependence of several bacterial species in the vagina.

Gram staining of the fluid and clinical criteria are used to make the diagnosis.

Criteria for diagnosis includes three of the following: thin milky vaginal discharge, pH of vaginal fluid greater than 4.5, production of a fishy odor when 10% KOH is added to a slide containing vaginal fluid, and greater than 20% of epithelial cells with adherent bacteria on microscopic exam of vaginal fluid.

Gram stain of vaginal fluid reveals gram-negative organisms which distinguishes it from normal flora which reveals gram-positive rods and lactobacilli.


Vaginal microbiome transplants in patients with chronic bacterial vaginosis resulted in long-term remission in 4 of 5 patients and lasted up to 21 months.

Responds to metronidazole and clindamycin, but relapse and persistence of infection common suggesting bacterial pathogenesis is poorly understood.

A genus of Gram-variable-staining facultative anaerobic bacteria of which G. vaginalis is the only species.

Grows as small, circular, convex, gray colonies on chocolate agar.

It also grows on HBT agar and a selective medium for G. vaginalis is colistin-oxolinic acid blood agar.

Can cause bacterial vaginosis in some women as a result of a disruption in the normal vaginal flora.

The resident facultative anaerobic Lactobacillus population in the vagina are responsible for the acidic environment, and if anaerobes supplant the normal vaginal bacteria, infection may result, requiring antibiotics with anaerobic coverage to eliminate the G. vaginalis and restore the balance.

Typically isolated in genital cultures.

G. vaginalis can also be isolated from women without any signs or symptoms of infection.

Has a Gram-positive cell wall, it which can appear either Gram-positive or Gram-negative under the microscope.

Microscopically associated with clue cells, which are epithelial cells covered in bacteria.

G. vaginalis produces a pore-forming toxin, vaginolysin, and Protease and sialidase enzyme activities.

Antibiotic treatments include metronidazole and clindamycin, in both oral and vaginal gel/cream forms.

The use of lactobacillus crispatus (Lactin-V) with vaginal metronidazole results in significantly lower incidence of recurrence of bacterial vaginosis than placebo at 12 weeks (Cohen CR).

Lactobacillus crispatus is a live bio therapeutic product that contains naturally occurring vaginal strain.

Symptoms may include vaginal discharge, vaginal irritation, and a vaginal fish-like odor.

The process may be asymptomatic.

When 10% KOH is added to the discharge, a positive result indicated if a fishy smell is produced and this and other tests can be used to distinguish between vaginal symptoms related to G. vaginalis from those caused by other organisms, such as Trichomonas and Candida albicans.

Trichomonas vaginalis and Gardnerella vaginalis have similar clinical presentations and can cause a frothy gray or yellow-green vaginal discharge, pruritus, and produce a positive fish odor test.

A wet mount slide, where a swab of the vaginal epithelium is diluted and then placed onto a slide for observation under a microscope., reveals a classic “clue cell” under the microscope with Gardnerella.

There is no evidence that screening for bacterial vaginosis lowers the rate of preterm delivery.





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