Bacterial Vaginosis

Bacterial vaginosis (BV) is a condition that happens when there is too much of certain bacteria in the vagina. This changes the normal balance of bacteria in the vagina.

Researchers do not know the cause of BV or how some women get it. We do know that the infection typically occurs in sexually active women. BV is linked to an imbalance of “good” and “harmful” bacteria that are normally found in a woman’s vagina. Having a new sex partner or multiple sex partners, as well as douching, can upset the balance of bacteria in the vagina. This places a woman at increased risk for getting BV.

We also do not know how sex contributes to BV.  There is no research to show that treating a sex partner affects whether or not a woman gets BV. Having BV can increase your chances of getting other STDs.

BV rarely affects women who have never had sex.

You cannot get BV from toilet seats, bedding, or swimming pools.

Doctors and scientists do not completely understand how BV spreads. There are no known best ways to prevent it.

The following basic prevention steps may help lower your risk of developing BV:

• Not having sex;
• Limiting your number of sex partners; and
• Not douching.

Pregnant women can get BV. Pregnant women with BV are more likely to have babies born premature (early) or with low birth weight than pregnant women without BV. Low birth weight means having a baby that weighs less than 5.5 pounds at birth.

Treatment is especially important for pregnant women.

Many women with BV do not have symptoms. If you do have symptoms, you may notice:

• A thin white or gray vaginal discharge;
• Pain, itching, or burning in the vagina;
• A strong fish-like odor, especially after sex;
• Burning when urinating;
• Itching around the outside of the vagina.

BV will sometimes go away without treatment. But if you have symptoms of BV you should be checked and treated. It is important that you take all of the medicine prescribed to you, even if your symptoms go away. A health care provider can treat BV with antibiotics, but BV may return even after treatment. Treatment may also reduce the risk for some STDs.

Male sex partners of women diagnosed with BV generally do not need to be treated. BV may be transferred between female sex partners.

BV can cause some serious health risks, including:

• Increasing your chance of getting HIV if you have sex with someone who is infected with HIV;
• If you are HIV positive, increasing your chance of passing HIV to your sex partner;
• Making it more likely that you will deliver your baby too early if you have BV while pregnant;
• Increasing your chance of getting other STDs, such as chlamydia and gonorrhea. These bacteria can sometimes cause pelvic inflammatory disease (PID), which can make it difficult or impossible for you to have children.

Division of STD Prevention (DSTDP)
Centers for Disease Control and Prevention
www.cdc.gov/std

CDC-INFO Contact Center
1-800-CDC-INFO (1-800-232-4636)
TTY: (888) 232-6348
Contact CDC-INFO

CDC National Prevention Information Network (NPIN)
P.O. Box 6003
Rockville, MD 20849-6003
E-mail: npin-info@cdc.gov

American Sexual Health Association (ASHA)
P. O. Box 13827
Research Triangle Park, NC 27709-3827
1-800-783-9877

Additional Sources

Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR, 64(RR-3) (2015).

Hillier S and Holmes K. Bacterial vaginosis. In: K. Holmes, P. Sparling, P. Mardh et al (eds). Sexually Transmitted Diseases, 3rd Edition. New York: McGraw-Hill, 1999, 563-586.

STDs during Pregnancy Fact Sheet

Pregnancy and HIV, Viral Hepatitis, and STD Prevention

Pelvic Inflammatory Disease (PID) Fact Sheet