Vaginose G15Bacterial vaginosis

The most common Sexually Transmitted Diseases (STDs) or Sexually Transmitted Infection (STI) or Venereal Disease (VD)

Bacterial vaginosis
Classification and external resources

Micrograph of bacterial vaginosis – squamous cells of the cervix covered with rod-shaped bacteria, Gardnerella vaginalis (arrows).


Bacterial vaginosis (BV) is the most common cause of vaginal infection.
It is not considered to be a sexually transmitted infection. BV is not transmitted through sexual intercourse but is more common in women who are sexually active.
BV is caused by an imbalance of naturally occurring bacterial flora and should not be confused with yeast infection (candidiasis), or infection with Trichomonas vaginalis (trichomoniasis), which are not caused by bacteria.

Symptoms and signs

The most common symptom of BV is an abnormal white vaginal discharge (especially after sex) with an unpleasant smell and is usually without irritation, pain or erythema.


A healthy vagina normally contains many microorganisms; some of the common ones are Lactobacillus crispatus and Lactobacillus jensenii. Lactobacillus, appears to help prevent other vaginal microorganisms from multiplying to a level where they cause symptoms.
A change in normal bacterial flora including the reduction of lactobacillus, 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. 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.
It is possible for virgins to get infected with bacterial vaginosis.
Pregnant women and women with sexually transmitted infections are especially at risk for getting this infection. Bacterial vaginosis may sometimes affect women after menopause.


Although previously considered a mere nuisance infection, untreated bacterial vaginosis may cause serious complications, such as increased susceptibility 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 (PID) following surgical procedures such as a hysterectomy or an abortion.

How is bacterial vaginosis diagnosed?

When a woman reports an unusual vaginal discharge, the doctor will ask her a series of routine questions to help distinguish mild from more serious conditions.
Additional issues that might indicate the presence of a more serious condition include fever, pelvic pain, new or multiple sexual partners (especially with unprotected intercourse), and a history of sexually-transmitted infections.
In addition to these questions, the doctor will perform a pelvic exam. During the exam, the doctor notes the appearance of the vaginal lining and cervix.
The doctor will also perform a manual exam of the ovaries and uterus. The cervix is examined for tenderness, which might indicate a more serious infection. The doctor may collect samples to check for chlamydia or gonorrhea infection.
Examining the vaginal discharge under the microscope can help distinguish bacterial vaginosis from yeast vaginitis (candidiasis) and trichomonas (a type of sexually transmitted infection).
A sign of bacterial vaginosis under the microscope is an unusual vaginal cell called a clue cell.
Clue cells are believed to be the most reliable diagnostic sign of bacterial vaginosis. In addition to clue cells, women with bacterial vaginosis have fewer of the normal vaginal bacteria, called lactobacilli. A vaginal pH greater than 4.5 is also suggestive of bacterial vaginosis.

Treatment for bacterial vaginosis :

Treatment for bacterial vaginosis consists of antibiotics. A few antibiotics are routinely used. Metronidazole (Flagyl) taken by either oral (pill) form or by vaginal metronidazole gel (Metrogel) is an effective treatment. Also available is the vaginal clindamycin cream (Cleocin). The oral metronidazole can cause some minor but unpleasant side effects, but is believed to be the most effective treatment. The gels do not typically cause side effects, although yeast vaginitis can occur as a side effect of the medication.

Tinidazole is an antibiotic that appears to have fewer side effects than metronidazole and is also effective in treating bacterial vaginosis.
Recurrence of bacterial vaginosis is possible even after successful treatment. More than half of those treated experience recurrent symptoms within 12 months. It is unclear why so many recurrent infections develop. With recurrent symptoms, a second course of antibiotics is generally prescribed.