Bacterial Vaginosis

Bacterial vaginosis (BV) is the name of a condition in women where the normal balance of bacteria in the vagina is disrupted and replaced by an overgrowth of certain bacteria. It is the most common vaginal infection in women of childbearing age. In the United States, as many as 16 percent of pregnant women have BV.

The vagina normally contains mostly "good" bacteria (e.g., Lactobacillus), and fewer "harmful" bacteria. BV develops when there is an increase in harmful bacteria such as Gardnerella vaginalis, Bacteroides, Mobiluncus, and Mycoplasma hominis. Researchers are studying the role that each of these germs may play in causing BV, but they do not yet understand the role of sexual activity in developing BV. A change in sexual partners, using an IUD (intrauterine device), and douching may increase a woman’s risk of getting BV.

Symptoms and Diagnosis

Women with BV may have an abnormal vaginal discharge with an unpleasant odor. Some women report a strong fish-like odor, especially after intercourse. Discharge, if present, is usually white or gray; it can be thin. Women with BV may also have burning during urination or itching around the outside of the vagina, or both. Some women with BV report no signs or symptoms at all.

A health care provider can examine a sample of vaginal fluid under a microscope, either stained or in special lighting, to look for bacteria associated with BV. Then, they can diagnose BV based on

• Absence of lactobacilli
• Presence of numerous "clue cells" (cells from the vaginal lining that are coated with BV germs)
• Fishy odor
• Change from normal vaginal fluid

Complications

In most cases, BV causes no complications. But there are some serious risks from BV including:

• Having BV can increase a woman's susceptibility to HIV infection if she is exposed to the HIV virus.

• Having BV increases the chances that an HIV-infected woman can pass HIV to her sex partner.

• Having BV has been associated with an increase in the development of pelvic inflammatory disease (PID) following surgical procedures such as a hysterectomy or an abortion.

• Having BV while pregnant may put a woman at increased risk for some complications of pregnancy.

• BV can increase a woman's susceptibility to other STDs, such as chlamydia and gonorrhea.

Treatment

Although BV will sometimes clear up without treatment, all women with symptoms of BV should be treated to avoid complications. Male partners generally do not need to be treated. However, BV may spread between female sex partners.

BV is treatable with antibiotics prescribed by a health care provider. Two different antibiotics are recommended as treatment for BV: metronidazole or clindamycin. Either can be used with non-pregnant or pregnant women, but the recommended dosages differ. Women with BV who are HIV-positive should receive the same treatment as those who are HIV-negative.

References:

Centers for Disease Control and Prevention, USA.
National Institute of Allergy and Infectious Diseases, USA.