Bacterial vaginosis

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Bacterial vaginosis

Bacterial vaginosis (BV) is the most common cause of vaginal infection (vaginitis

Vaginitis

Vaginitis is an inflammation of the vaginal mucosa and often associated with an irritation or infection of the vulva leading to vulvovaginitis....
). For grammatical reasons, some people prefer to call it vaginal bacteriosis. It is not generally considered to be a sexually transmitted infection (see causes below). BV is caused by an imbalance of naturally occurring bacterial flora, and should not be confused with yeast infection (candidiasis

Candidiasis

Candidiasis, commonly called yeast infection or thrush, is a fungal infection of any of the Candida species, of which Candida albicans is the most common....
), or infection with Trichomonas vaginalis
Trichomonas vaginalis

Trichomonas vaginalis, an Anaerobic organism, parasite flagellated protozoan, is the causative agent of trichomoniasis, and is the most common pathogenic protozoan infection of humans in industrialized countries....
(trichomoniasis

Trichomoniasis

Trichomoniasis, sometimes referred to as "trich", is a common cause of vaginitis. It results both from shared external water sources , and as a sexually transmitted disease ....
) which are not caused by bacteria

Bacteria

The Bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals....
.

Hemena is a bacterial infection of the vagina.

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Encyclopedia

Bacterial vaginosis (BV) is the most common cause of vaginal infection (vaginitis

Vaginitis

Candidiasis

Trichomoniasis

Bacteria

Hymen

The hymen is a fold of mucous membrane which surrounds or partially covers the external vaginal opening. It forms part of the vulva, or external genitalia....
. Not to be confused with yeast infections, this disease can only occur in women. Its an unhealthy amount of bacteria infecting the membrane.

Symptoms and signs

The most common symptom of BV is an abnormal vaginal discharge

Mucopurulent discharge

Mucopurulent discharge is the emission or secretion of fluid containing mucus and pus from the eye, nose, cervix, vagina, or other part of the body due to infection and inflammation....
(especially after sex) with an unpleasant fishy smell. While some women do not experience symptoms, many women experience intense itching, swelling and irritation (which is why it is often misdiagnosed by patients and even health care practitioners as a yeast infection), as well as stomach pains, which feel like severe cramps. By contrast, a 'normal' discharge will be odorless and will vary in consistency and amount with the menstrual cycle

Menstrual cycle

The menstrual cycle is a recurring cycle of physiology changes that occurs in reproductive-age females. Overt menstruation occurs primarily in humans and close evolutionary relatives such as chimpanzees....
- a normal discharge is at its clearest about 2 weeks before the period

Menstruation

See also "Mensuration", a term sometimes used to describe Measurement, particularly in the context of forestry.Menstruation is the shedding of the uterine lining ....
starts.

Diagnosis

A healthcare professional seeing a woman presenting with questions about vaginal discharge and irritation in the vagina and vulva will have several diagnoses in mind to account for it. These may include:

The discharge is normal for the woman
Candidiasis
Candidiasis

Candidiasis, commonly called yeast infection or thrush, is a fungal infection of any of the Candida species, of which Candida albicans is the most common....
(thrush, or a yeast infection)
Trichomoniasis
Trichomoniasis

Trichomoniasis, sometimes referred to as "trich", is a common cause of vaginitis. It results both from shared external water sources , and as a sexually transmitted disease ....
, an infection caused by Trichomonas vaginalis
Trichomonas vaginalis

Trichomonas vaginalis, an Anaerobic organism, parasite flagellated protozoan, is the causative agent of trichomoniasis, and is the most common pathogenic protozoan infection of humans in industrialized countries....
Bacterial vaginosis

Simple tests can be done to make the proper diagnosis. The healthcare provider will carry out a speculum

Speculum (medical)

A speculum is a medical tool for investigating body cavities, with a form dependent on the body cavity for which it is designed. In old texts, the speculum may also be referred to as a diopter or dioptra....
examination and take some swabs from high in the vagina. These swabs will be tested for:

A characteristic "fishy" odor on wet mount. This test, called the "whiff test", is performed by adding a small amount of potassium hydroxide
Potassium hydroxide

Potassium hydroxide is the inorganic compound with the formula potassiumhydroxide. Along with sodium hydroxide, this colourless solid is a prototypical "strong base"....
to a microscopic slide containing the vaginal discharge. A characteristic "fishy" odor is considered a positive whiff test and is suggestive of bacterial vaginosis.
Loss of acidity. To control bacterial growth, the vagina is normally slightly acidic with a pH
PH

pH is a measure of the Acid or Base of a solution. It is defined as the cologarithm of the Activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations....
of 3.8–4.2. A swab of the discharge is put onto litmus paper to check its acidity. A pH greater than 4.5 is considered alkaline and is suggestive of bacterial vaginosis.
The presence of clue cell
Clue cell

Clue cells are epithelial cells of the vagina that get their distinctive stippled appearance by being covered with bacteria.They are a medical sign of bacterial vaginosis, particularly that caused by Gardnerella vaginalis, a group of Gram-negative bacteria....
s on wet mount. Similar to the whiff test, the test for clue cells is performed by placing a drop of sodium chloride
Sodium chloride

Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with the chemical formula SodiumChlorine....
solution on a slide containing vaginal discharge. If present, clue cells can be visualized under a microscope. They are so-named because they give a clue to the reason behind the discharge. These are epithelial cells (like skin) that are coated with bacteria.

Two positive results in addition to the discharge itself are enough to diagnose BV. If there is no discharge, then all three criteria are needed. A 1990 study demonstrated that the single best test for BV was the test for clue cells on wet mount examination. The best combination of two tests for BV was the test for clue cells and the whiff test.

In clinical practice

In clinical practice BV is diagnosed using the Amsel criteria:

Thin, white, yellow, homogeneous discharge
Clue cells on microscopy
Microscopy

Microscopy is the technical field of using microscopes to view samples or objects. There are three well-known branches of microscopy, optical microscopy, electron microscopy and scanning probe microscopy....
pH
PH

pH is a measure of the Acid or Base of a solution. It is defined as the cologarithm of the Activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations....
of vaginal fluid >4.5
Release of a fishy odor on adding alkali
Alkali

In chemistry, an alkali is a Base , Ionic compound salt of an alkali metal or alkaline earth metal Chemical element. Alkalis are best known for being Base s that dissolve in water....
—10% potassium hydroxide
Potassium hydroxide

Potassium hydroxide is the inorganic compound with the formula potassiumhydroxide. Along with sodium hydroxide, this colourless solid is a prototypical "strong base"....
(KOH) solution.

At least three of the four criteria should be present for a confirmed diagnosis.

An alternative is to use a Gram stained vaginal smear, with the Hay/Ison criteria or the Nugent criteria. The Hay/Ison criteria are defined as follows:

Grade 1 (Normal): Lactobacillus
Lactobacillus

Lactobacillus is a genus of Gram-positive facultative anaerobic or microaerophilic bacteria. They are a major part of the lactic acid bacteria group, named as such because most of its members convert lactose and other sugars to lactic acid....
morphotypes predominate.
Grade 2 (Intermediate): Mixed flora with some Lactobacilli present, but Gardnerella or Mobiluncus morphotypes also present.
Grade 3 (Bacterial Vaginosis): Predominantly Gardnerella and/or Mobiluncus morphotypes. Few or absent Lactobacilli. (Hay et al., 1994)

What this technique loses in interobserver reliability, it makes up in ease and speed of use.

The standard for research are the Nugent Criteria. In this scale a score of 0-10 is generated from combining three other scores. It is time consuming and requires trained staff but is has high interobserver reliability:

0–3 is considered negative for BV
4–6 is considered intermediate
7+ is considered indicative of BV.

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 Gardnerella 'Gardnerella' is a genus of gram-positive Aerobic organism bacteria of which 'Gardnerella vaginalis' is the only species.Once classified as a species of Haemophilus, G.... / Bacteroides Bacteroides *Bacteroides* is a genus of Gram-negative, bacillus Bacterium. Bacteroides species are non-endospore-forming, Anaerobic bacteria, and may be either motile or non-motile, depending on the species.... morphotypes — average per high powered (1000× oil immersion) field. View multiple fields.	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) >- \| Score 0 for >30 Score 1 for 15–30 Score 2 for 14 Score 3 for <1 (this is an average, so results can be >0, yet <1) Score 4 for 0	Score 0 for 0 Score 1 for <1 (this is an average, so results can be >0, yet <1) Score 2 for 1–4 Score 3 for 5–30 Score 4 for >30	Score 0 for 0 Score 1 for <5 Score 2 for 5+

A recent study compared the gram stain using the Nugent criteria and the DNA hybridization test Affirm VPIII in diagnosing BV. The Affirm VPIII test detected Gardnerella in 107 (93.0%) of 115 vaginal specimens positive for BV diagnosed by gram stain. The Affirm VPIII test has a sensitivity of 87.7% and specificity of 96% and may be used for the rapid diagnosis of BV in symptomatic women.

Causes

A healthy vagina normally contains many microorganisms; some of the common ones are Lactobacillus crispatus and Lactobacillus jensenii. Lactobacillus, particularly hydrogen peroxide-producing species, appears to help prevent other vaginal microorganisms from multiplying to a level where they cause symptoms. (Note: Lactobacillus acidophilus
Lactobacillus acidophilus

Lactobacillus acidophilus is one species in the genus Lactobacillus. It is sometimes used commercially together with Streptococcus salivarius and Lactobacillus bulgaricus in the production of acidophilus-type yogurt....
is not one of the species of Lactobacillus identified as playing a protective role in vaginal flora.) The microorganisms involved in BV are very diverse, but include Gardnerella vaginalis, Mobiluncus
Mobiluncus

Mobiluncus is a genus of gram-negative, anaerobic, rod-shaped bacteria. Its organisms are found in the human vagina, particularly in association with Gardnerella vaginalis in cases of bacterial vaginosis....
, Bacteroides
Bacteroides

Bacteroides is a genus of Gram-negative, bacillus Bacterium. Bacteroides species are non-endospore-forming, Anaerobic bacteria, and may be either motile or non-motile, depending on the species....
, and Mycoplasma
Mycoplasma

Mycoplasma is a genus of bacterium which lack a cell wall. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis....
. A change in normal bacterial flora including the reduction of lactobacillus, which may be due to the use of antibiotics or pH imbalance, allows more resistant bacteria to gain a foothold and multiply. In turn these produce toxins which affect the body's natural defenses and make re-colonization of healthy bacteria more difficult.

There are a variety of causes for bacterial vaginosis. Thongs are notorious for causing bacterial vaginosis due to the cloth rubbing against the anus and vagina. Cases of bacterial vaginosis are more likely to occur in sexually active women between the ages of 15 and 44, especially after contact with a new partner. Condom

Condom

A condom is a device most commonly used during sexual intercourse. It is put on a man's erect penis and physically blocks ejaculated semen from entering the body of a sexual partner....
s may provide some protection and there is no evidence that spermicide

Spermicide

Spermicide is a substance that kills spermatozoon, inserted vaginally prior to intercourse to prevent pregnancy. As a contraceptive, spermicide may be used alone....
increases BV risk. Although BV can be associated with sexual activity, there is no clear evidence of sexual transmission. It is possible for virgins to get infected with bacterial vaginosis. Rather, BV is a disordering of the chemical and biological balance of the normal flora. Recent research is exploring the link between sexual partner treatment and eradication of recurrent cases of BV. Pregnant

Pregnancy

Pregnancy is the carrying of one or more offspring, known as a fetus or embryo, inside the uterus of a female. In a pregnancy, there can be multiple gestations, as in the case of twins or Multiple birth....
women and women with sexually transmitted infections are especially at risk for getting this infection. Bacterial vaginosis may sometimes affect women after menopause

Menopause

The Menopause is the permanent cessation of menstruation which occurs a considerable length of time before the end of the lifespan.The word was first applied to humans, and because of this it literally means the cessation of monthly cycles or menstrual cycles, from the Greek roots meno and pausis ....
. A 2005 study by researchers at Ghent University

Ghent University

Ghent University is one of the three large Flanders university. It is located in the historic town of Ghent in Flanders, the Dutch language-speaking part of Belgium....
in Belgium showed that subclinical iron deficiency (anemia

Anemia

Anemia or an?mia/anaemia is defined as a qualitative or quantitative deficiency of hemoglobin, a protein found inside red blood cells ....
) was a strong predictor of bacterial vaginosis in pregnant women. A longitudinal study published in February 2006 in the American Journal of Obstetrics and Gynecology showed a link between psychosocial stress and bacterial vaginosis independent of other risk factors.

A higher incidence in women who have sex with women

Women who have sex with women

Women who have sex with women is a term used to identify women who have sex with other women, but may or may not self-identify as lesbian or bisexual....
have led some to hypothesize that sexual exchange of vaginal secretions is a possible mechanism for acquisition.

In pre-pubescent girls, bacterial vaginosis may be caused by strep

STReP

Specific Targeted Research Projects are medium-sized research projects funded by the European Commission in the FP6 funding program. STReP projects are composed by a minimum of 3 partners coming from 3 different countries from Associated states....
, or by bacteria introduced from the anus due to improper hygiene (wiping) after bowel movements.

Complications

Although previously considered a mere nuisance infection, untreated bacterial vaginosis may cause serious complications, such as increased succeptibility to sexually transmitted infections including HIV, and may present other complications for pregnant women. It has also been associated with an increase in the development of Pelvic inflammatory disease

Pelvic inflammatory disease

Pelvic inflammatory disease is a generic term for inflammation of the female uterus, fallopian tubes, and/or ovaries as it progresses to scar formation with Adhesion to nearby tissues and organs....
(PID) following surgical procedures such as a hysterectomy or an abortion.

Treatment

Bacterial vaginosis can be treated with antibiotic

Antibiotic

In common usage, an antibiotic is a substance or compound that kills or inhibits the growth of bacteria. Antibiotics belong to the group of antimicrobial compounds used to treat infections caused by microorganisms, including fungus and protozoa....
s such as metronidazole

Metronidazole

Metronidazole is a nitroimidazole antibiotic medication used mainly in the treatment of infections caused by susceptible organisms, particularly anaerobe bacterium and protozoa....
and clindamycin

Clindamycin

Clindamycin is a lincosamides antibiotic. It is usually used to treat infections with anaerobic organism bacteria but can also be used to treat some protozoal diseases, such as malaria....
. However, there is a high rate of recurrence. Moreover metronidazole is a suspected carcinogen. It is banned in EU for veterinary use as it is proved carcinogenic in animals.

BV is twice as common as thrush and it is estimated that 1 in 3 women will develop the condition at some point in their lives. In addition to the physical discomfort and symptoms, BV can also have a significant impact on a woman’s quality of life.

Currently, there are very few over the counter

Over-the-counter drug

Over-the-counter drugs are medications that may be sold to a customer without a medical prescription. The term "over-the-counter" is somewhat counter-intuitive, since these items can often be found on the shelves of stores and bought like any other packaged product in some countries in contrast to prescription drug which are more likely to l...
products that address bacterial vaginosis. They work after different principles:

Eliminating the unwanted bacteria. Example Tea-tree oil products, FemiGel. Same principle as the antibiotics.
Adding buffer / acid to lower the pH. RepHresh is an example.
Adding lactic bacteria. Fem-dophilus (Jarrow Formulas) is a lactobacillus product which specifically claims to help maintain healthy vaginal flora.
Adding growth substrate for the beneficial lactic acid bacteria to grow and produce lactic acid directly into the vagina. The natural lactic acid bacteria multiply, bringing about a healthy environment. LadyBalance is based on this principle .

Most of the over-the-counter products are not documented by clinical trials. But as many women cannot eliminate bacterial vaginosis by prescription drugs, they select from the above mentioned products.