What is bacterial vaginosis?

Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age, and it is sometimes accompanied by discharge, odor, pain, itching, or burning.

What causes bacterial vaginosis?

The cause of BV is not fully understood. BV is associated with an imbalance in the bacteria that are normally found in a woman's vagina. The vagina normally contains mostly "good" bacteria, and fewer "harmful" bacteria. BV develops when there is a change in the environment of the vagina that causes an increase in harmful bacteria.

How do women get bacterial vaginosis?

Not much is known about how women get BV. Women who have a new sex partner or who have had multiple sex partners are more likely to develop BV. Women who have never had sexual intercourse are rarely affected. It is not clear what role sexual activity plays in the development of BV, and there are many unanswered questions about the role that harmful bacteria play in causing BV. Women do not get BV from toilet seats, bedding, swimming pools, or from touching objects around them.

How common is bacterial vaginosis?

Scientific studies suggest that BV is common in women of reproductive age. In the United States, as many as 16% of pregnant women have BV. BV is generally more commonly seen in women attending STD clinics than in those attending family planning or prenatal clinics.

What are the signs and symptoms of bacterial vaginosis?

Women with BV often have an abnormal vaginal discharge with an unpleasant odor. Some women report a strong fish-like odor, especially after intercourse. The discharge 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.

How is bacterial vaginosis diagnosed?

A health care provider must examine the vagina for signs of BV (e.g., discharge) and perform laboratory tests on a sample of vaginal fluid to look for bacteria associated with BV.

Who is at risk for bacterial vaginosis?

Any woman can get BV. However, some activities or behaviors can upset the normal balance of bacteria in the vagina and put women at increased risk:

• Having a new sex partner or multiple sex partners
  
  
• Douching
  
  
• Using an intrauterine device (IUD) for contraception.

Pregnant women are at increased risk for complications of BV.

What are the complications of bacterial vaginosis?

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

• Pregnant women with BV more often have babies who are born early or with low birth weight.
  
  
• The bacteria that cause BV can sometimes infect the uterus (womb) and fallopian tubes (egg canals). This type of infection is called pelvic inflammatory disease (PID). PID can cause infertility or damage the fallopian tubes enough to increase the future risk of ectopic pregnancy and infertility. Ectopic pregnancy is a life-threatening condition in which a fertilized egg grows outside the uterus, usually in a fallopian tube.
  
  
• BV can increase a woman's susceptibility to HIV infection if she is exposed to the virus.
  
  
• Having BV increases the chances that an HIV-infected woman can pass HIV to her sex partner.
  
  
• BV can increase a woman's susceptibility to other STDs, such as chlamydia and gonorrhea.

Who should be treated for bacterial vaginosis?

Although BV will sometimes clear up without treatment, all women diagnosed with BV should be treated to avoid such complications as PID. Treatment is especially important for pregnant women. All pregnant women, regardless of symptoms, who have ever had a premature delivery or low birth weight baby should be considered for a BV examination and be treated when necessary. All pregnant women who have symptoms of BV should be checked and treated. Male partners generally do not need to be treated. However, BV may spread between female sex partners.

What is the treatment for bacterial vaginosis?

BV is treatable with antimicrobial medicines prescribed by a health care provider. Two different medicines are recommended as treatment for BV: metronidazole or clindamycin. Either can be used with non-pregnant or with 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. BV can recur after treatment.

How can bacterial vaginosis be prevented?

BV is not completely understood by scientists, and the best ways to prevent it are unknown. However, enough is known to show that BV is associated with having a new sex partner or having multiple sex partners. It is seldom found in women who have never had intercourse.

Some basic prevention steps can help reduce the risk of upsetting the natural balance in the vagina and developing BV:

• Not having sex is the best protection against acquiring BV and other STDs.
  
  
• Having sex with only one uninfected partner who only has sex with you is safe.
  
  
• Using latex condoms, consistently and correctly, can reduce the risk of transmission of BV and other STDs.
  
  
• Limit the number of sex partners.
  
  
• Do not douche.
  
  
• Use all of the medicine prescribed for treatment of BV, even if the signs and symptoms go away.

Where can I get more information?

Illinois Department of Public Health
HIV/STD Hotline 800-243-2437 (TTY 800-782-0423)

Centers for Disease Control and Prevention (CDC)
CDC-INFO Hotline (24 hours, 7 days a week)
STD information and referrals to STD Clinics
800-CDC-INFO (800-232-4636)
TTY: 888-232-6348
In English, en Español

CDC National Prevention Information Network (NPIN)
P.O. Box 6003
Rockville, MD 20849-6003
800-458-5231
888-282-7681 Fax
800-243-7012 TTY
E-mail: info@cdcnpin.org

American Social Health Association (ASHA)
P. O. Box 13827
Research Triangle Park, NC 27709-3827
800-783-9877