What is bacterial vaginosis

Bacterial vaginosis is a common infection of the vagina when there is too much of certain bacteria in the vagina, any woman can get bacterial vaginosis. Bacterial vaginosis is the most common vaginal infection in women ages 15-44. Although the actual cause of bacterial vaginosis is currently unknown, scientists believed bacterial vaginosis is linked to an imbalance of “good” and “harmful” bacteria that are normally found in a woman’s vagina. Bacterial vaginosis is harmless and easily treated. Bacterial vaginosis is not classed as a sexually transmitted infection (STI) or sexually transmitted disease (STD). However, having bacterial vaginosis can increase your chance of getting a STD (e.g., HIV, N. gonorrhoeae, C. trachomatis, and HSV- 2) including developing pelvic inflammatory disease (PID). Bacterial vaginosis also increases the risk for HIV transmission to male sex partners ¹. Although bacterial vaginosis-associated bacteria can be found in the male genitalia, treatment of male sex partners has not been beneficial in preventing the recurrence of bacterial vaginosis ².

Please note, bacterial vaginosis must not be confused with vaginitis (inflammation of the vagina). Vaginitis is defined as any condition with symptoms of abnormal vaginal discharge, odor, irritation, itching, or burning ³. The most common causes of vaginitis are bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis ³. Bacterial vaginosis is implicated in 40% to 50% of vaginitis cases when a cause is identified, with vulvovaginal candidiasis accounting for 20% to 25% and trichomoniasis for 15% to 20% of cases. Noninfectious causes, including atrophic, irritant, allergic, and inflammatory vaginitis, are less common and account for 5% to 10% of vaginitis cases. Most women have at least one episode of vaginitis during their lives, making it the most common gynecologic diagnosis in primary care ³.

Key facts

• Bacterial vaginosis is the most common vaginal condition in women ages 15 to 44 ⁴. But women of any age can get it, even if they have never had sex.
  • Researchers are still studying how women get bacterial vaginosis. You can get bacterial vaginosis without having sex, but bacterial vaginosis is more common in women who are sexually active. Having a new sex partner or multiple sex partners, as well as douching, can upset the balance of good and harmful bacteria in your vagina ⁴. This raises your risk of getting bacterial vaginosis.
• The Centers for Disease Control and Prevention (CDC) recommends all women with bacterial vaginosis should be tested for HIV and other sexually transmitted diseases (STDs) ⁵.
• Bacterial vaginosis is the most common cause of vaginal symptoms among women, but it is not clear what role sexual activity plays in the development of bacterial vaginosis.
• You may be more at risk for bacterial vaginosis if you:
  • Have a new sex partner
  • Have multiple sex partners
  • Douche ⁶
  • Do not use condoms or dental dams
  • Are pregnant. bacterial vaginosis is common during pregnancy. About 1 in 4 pregnant women get bacterial vaginosis ⁷. The risk for bacterial vaginosis is higher for pregnant women because of the hormonal changes that happen during pregnancy.
  • Are African-American. bacterial vaginosis is twice as common in African-American women as in white women ⁸
  • Have an intrauterine device (IUD), especially if you also have irregular bleeding ⁹

The prevalence in the United States is estimated to be 21.2 million (29.2%) among women ages 14–49, based on a nationally representative sample of women who participated in NHANES 2001–2004. The following are other findings from this study ¹⁰.

• Most women found to have bacterial vaginosis (84%) reported no symptoms.
• Women who have not had vaginal, oral, or anal sex can still be affected by bacterial vaginosis (18.8%), as can pregnant women (25%), and women who have ever been pregnant (31.7%).
• Prevalence of bacterial vaginosis increases based on lifetime number of sexual partners.
• Non white women have higher rates (African-American 51%, Mexican Americans 32%) than white women (23%).

Bacterial vaginosis is traditionally diagnosed with Amsel criteria, although Gram stain is the diagnostic standard ³.

Bacterial vaginosis is treated with oral metronidazole, intravaginal metronidazole, or intravaginal clindamycin ³. Treatment is especially important for pregnant women. Pregnant women with bacterial vaginosis may deliver premature (early) or low birth-weight babies.

Recommended antibiotics for bacterial vaginosis ⁵:

• Metronidazole 500 mg orally twice a day for 7 days
• OR Metronidazole gel 0.75%, one full applicator (5 g) intravaginally, once a day for 5 days
• OR Clindamycin cream 2%, one full applicator (5 g) intravaginally at bedtime for 7 days

Alcohol consumption should be avoided during treatment with nitroimidazoles. To reduce the possibility of a disulfiram-like reaction, abstinence from alcohol use should continue for 24 hours after completion of metronidazole. Clindamycin cream is oil-based and might weaken latex condoms and diaphragms for 5 days after use (refer to clindamycin product information for additional information).

Women should be advised to refrain from sexual activity or use condoms consistently and correctly during the treatment regimen. Douching might increase the risk for relapse, and no data support the use of douching for treatment or relief of symptoms.

You can buy treatments for bacterial vaginosis over the counter, but there’s no clear proof they work.

Home remedies for bacterial vaginosis

To help relieve symptoms and prevent bacterial vaginosis from returning:

DO

• use water and an emollient, such as E45 cream, or plain soap to wash your genital area
• have showers instead of baths
• stay out of hot tubs or whirlpool baths.
• wash your vagina and anus with a gentle, non-deodorant soap.
• rinse completely and gently dry your genitals well.
• use unscented tampons or pads.
• wear loose-fitting clothing and cotton underwear. Avoid wearing pantyhose.
• wipe from front to back after you use the bathroom.

DON’T

• use perfumed soaps, bubble bath or shower gel
• use vaginal deodorants, washes or douches
• put antiseptic liquids in the bath
• use strong detergents to wash your underwear
• smoke

How do you get bacterial vaginosis?

Researchers do not know the cause of bacterial vaginosis or how some women get it. Scientists do know that the infection typically occurs in sexually active women. Bacterial vaginosis 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 bacterial vaginosis.

Researchers also do not know how sex contributes to bacterial vaginosis. There is no research to show that treating a sex partner affects whether or not a woman gets bacterial vaginosis. Having bacterial vaginosis can increase your chances of getting other sexually transmitted infections (STIs).

Bacterial vaginosis rarely affects women who have never had sex.

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

How can I avoid getting bacterial vaginosis?

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

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

• Not having sex;
• Limiting your number of sex partners;
• Always using a condom when you have sex; and
• Not douching. Douching removes the healthy bacteria in your vagina that protect against infection.

How do I know if I have bacterial vaginosis?

Many women with bacterial vaginosis 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.

How will my doctor know if I have bacterial vaginosis?

A health care provider will examine your vagina for signs of vaginal discharge. Your provider can also perform laboratory tests on a sample of vaginal fluid to determine if bacterial vaginosis is present. Bacterial vaginosis is traditionally diagnosed with Amsel criteria, although Gram stain is the diagnostic standard ³.

What happens if I don’t get treated?

Bacterial vaginosis can cause some serious health risks, including ⁵:

• 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 bacterial vaginosis while pregnant. Bacterial vaginosis can lead to premature birth or a low-birth-weight baby (smaller than 5 1/2 pounds at birth). All pregnant women with symptoms of bacterial vaginosis should be tested and treated if they have it;
• 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.

Recurring bacterial vaginosis

It’s common for bacterial vaginosis to come back, usually within 3 months.

You’ll need to take treatment for longer (up to 6 months) if you keep getting bacterial vaginosis (you get it more than twice in 6 months). Your doctor or sexual health clinic will recommend how long you need to treat it.

They can also help identify if something is triggering your bacterial vaginosis, such as sex or your period.

Can bacterial vaginosis be cured?

Bacterial vaginosis will sometimes go away without treatment. But if you have symptoms of bacterial vaginosis 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. Your doctor can treat bacterial vaginosis with antibiotics, but bacterial vaginosis may recur even after treatment. Treatment may also reduce the risk for some STDs (sexually transmitted diseases).

Male sex partners of women diagnosed with bacterial vaginosis generally do not need to be treated. bacterial vaginosis may be transferred between female sex partners ¹².

How can I lower my risk of bacterial vaginosis?

Researchers do not know exactly how bacterial vaginosis spreads. Steps that might lower your risk of bacterial vaginosis include:

• Keeping your vaginal bacteria balanced. Use warm water only to clean the outside of your vagina. You do not need to use soap. Even mild soap can cause irritate your vagina. Always wipe front to back from your vagina to your anus. Keep the area cool by wearing cotton or cotton-lined underpants.
• Not douching. Douching upsets the balance of good and harmful bacteria in your vagina. This may raise your risk of bacterial vaginosis. It may also make it easier to get bacterial vaginosis again after treatment. Doctors do not recommend douching.
• Not having sex. Researchers are still studying how women get bacterial vaginosis. You can get bacterial vaginosis without having sex, but bacterial vaginosis is more common in women who have sex.
• Limiting your number of sex partners. Researchers think that your risk of getting bacterial vaginosis goes up with the number of partners you have.

How can I protect myself if I am a female and my female partner has bacterial vaginosis?

If your partner has bacterial vaginosis, you might be able to lower your risk by using protection during sex.

• Use a dental dam every time you have sex. A dental dam is a thin piece of latex that is placed over the vagina before oral sex.
• Cover sex toys with condoms before use. Remove the condom and replace it with a new one before sharing the toy with your partner.

What is the difference between bacterial vaginosis and a vaginal yeast infection?

Bacterial vaginosis and vaginal yeast infections are both common causes of vaginal discharge. They have similar symptoms, so it can be hard to know if you have bacterial vaginosis or a yeast infection. Only your doctor or nurse can tell you for sure if you have bacterial vaginosis.

With bacterial vaginosis, your discharge may be white or gray but may also have a fishy smell. Discharge from a yeast infection may also be white or gray but may look like cottage cheese.

What should I do if I have bacterial vaginosis?

Bacterial vaginosis is easy to treat. If you think you have bacterial vaginosis:

• See a doctor. Antibiotics will treat bacterial vaginosis.
• Take all of your medicine. Even if symptoms go away, you need to finish all of the antibiotic.
• Tell your sex partner(s) if she is female so she can be treated.
• Avoid sexual contact until you finish your treatment.
• See your doctor again if you have symptoms that don’t go away within a few days after finishing the antibiotic.

Is it safe to treat pregnant women who have bacterial vaginosis?

Yes. The medicine used to treat bacterial vaginosis is safe for pregnant women. All pregnant women with symptoms of bacterial vaginosis should be tested and treated if they have it.

If you do have bacterial vaginosis, you can be treated safely at any stage of your pregnancy. You will get the same antibiotic given to women who are not pregnant.

Bacterial vaginosis in pregnancy

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

Treatment is especially important for pregnant women and is recommended for all symptomatic pregnant women. Studies have been undertaken to determine the efficacy of bacterial vaginosis treatment among pregnant women, including two trials demonstrating that metronidazole was efficacious during pregnancy using the 250-mg regimen ¹³, ¹⁴; however, metronidazole administered at 500 mg twice daily can be used. One trial involving a limited number of participants revealed treatment with oral metronidazole 500 mg twice daily to be equally effective as metronidazole gel, with cure rates of 70% using Amsel criteria to define cure ¹⁵. Another trial demonstrated a cure rate of 85% using Gram-stain criteria after treatment with oral clindamycin ¹⁶. Multiple studies and meta-analyses have failed to demonstrate an association between metronidazole use during pregnancy and teratogenic or mutagenic effects in newborns ¹⁷, ¹⁸. Although older studies indicated a possible link between use of vaginal clindamycin during pregnancy and adverse outcomes for the newborn, newer data demonstrate that this treatment approach is safe for pregnant women ¹⁹. Because oral therapy has not been shown to be superior to topical therapy for treating symptomatic bacterial vaginosis in effecting cure or preventing adverse outcomes of pregnancy, symptomatic pregnant women can be treated with either of the oral or vaginal regimens recommended for nonpregnant women. Although adverse pregnancy outcomes, including premature rupture of membranes, preterm labor, preterm birth, intra-amniotic infection, and postpartum endometritis have been associated with symptomatic bacterial vaginosis in some observational studies, treatment of bacterial vaginosis in pregnant women can reduce the signs and symptoms of vaginal infection. A meta-analysis has concluded that no antibiotic regimen prevented preterm birth (early or late) in women with bacterial vaginosis (symptomatic or asymptomatic). However, in one study, oral bacterial vaginosis therapy reduced the risk for late miscarriage, and in two additional studies, such therapy decreased adverse outcomes in the neonate ²⁰.

Treatment of asymptomatic bacterial vaginosis among pregnant women who are at high risk for preterm delivery (i.e., those with a previous preterm birth) has been evaluated by several studies, which have yielded mixed results. Seven trials have evaluated treatment of pregnant women with asymptomatic bacterial vaginosis at high risk for preterm delivery: one showed harm ²¹, two showed no benefit ²², ²³, and four demonstrated benefit ¹³, ¹⁴, ²⁴, ²⁵.

Similarly, data are inconsistent regarding whether treatment of asymptomatic bacterial vaginosis among pregnant women who are at low risk for preterm delivery reduces adverse outcomes of pregnancy. One trial demonstrated a 40% reduction in spontaneous preterm birth among women using oral clindamycin during weeks 13–22 of gestation ²⁵. Several additional trials have shown that intravaginal clindamycin given at an average gestation of >20 weeks did not reduce likelihood of preterm birth ²³, ²⁶. Therefore, evidence is insufficient to recommend routine screening for bacterial vaginosis in asymptomatic pregnant women at high or low risk for preterm delivery for the prevention of preterm birth ²⁷.

Although metronidazole crosses the placenta, no evidence of teratogenicity or mutagenic effects in infants has been found in multiple cross-sectional and cohort studies of pregnant women ²⁸. Data suggest that metronidazole therapy poses low risk in pregnancy ²⁹.

Metronidazole is secreted in breast milk. With maternal oral therapy, breastfed infants receive metronidazole in doses that are less than those used to treat infections in infants, although the active metabolite adds to the total infant exposure. Plasma levels of the drug and metabolite are measurable, but remain less than maternal plasma levels ³⁰. Although several reported case series found no evidence of metronidazole-associated adverse effects in breastfed infants, some clinicians advise deferring breastfeeding for 12–24 hours following maternal treatment with a single 2-g dose of metronidazole ³¹. Lower doses produce a lower concentration in breast milk and are considered compatible with breastfeeding ³². Data from studies of human subjects are limited regarding the use of tinidazole in pregnancy; however, animal data suggest that such therapy poses moderate risk. Thus tinidazole should be avoided during pregnancy ²⁹.

Bacterial vaginosis symptoms

In many cases, bacterial vaginosis does not cause any signs or symptoms. At other times, bacterial vaginosis may cause:

• A white (milky) or gray vaginal discharge that coats the walls of the vagina. It may also be foamy or watery.
• Vaginal discharge with an unpleasant or fish-like odor, especially after sex
• Vaginal pain or itching inside and outside the vagina
• Burning during urination
• Vaginal irritation

These symptoms may be similar to vaginal yeast infections and other health problems. Only your doctor or nurse can tell you for sure whether you have bacterial vaginosis. Doctors are unsure of the incubation period for bacterial vaginosis.

Bacterial vaginosis causes

Bacterial vaginosis occurs when there’s a change in the natural balance of bacteria in your vagina. What causes this to happen isn’t fully known, but you’re more likely to get it if:

• you’re sexually active
• you’ve had a change of partner
• you have an IUD (contraception intrauterine device)
• you use perfumed products in or around your vagina

Bacterial vaginosis is not classed as an STI, even though it can be triggered by sex. A woman can pass it to another woman during sex.

But women who haven’t had sex can also get bacterial vaginosis.

Bacterial vaginosis is a polymicrobial clinical syndrome resulting from replacement of the normal hydrogen peroxide producing Lactobacillus sp. in the vagina with high concentrations of anaerobic bacteria (e.g., Prevotella sp. and Mobiluncus sp.), Gardnerella Vaginalis, Ureaplasma, Mycoplasma, and numerous fastidious or uncultivated anaerobes ³³. Lactobacillus is a genus of Gram-positive, facultative anaerobic or microaerophilic, rod-shaped, non-spore-forming bacteria. Lactobacillus sp. are a major part of the lactic acid bacteria group (i.e. they convert sugars to lactic acid) in your vagina. Some women experience transient vaginal microbial changes, whereas others experience them for longer intervals of time. Among women presenting for care, bacterial vaginosis is the most prevalent cause of vaginal discharge or malodor; however, in a nationally representative survey, most women with bacterial vaginosis were asymptomatic ³⁴.

Bacterial vaginosis is associated with having multiple male or female partners, a new sex partner, douching, lack of condom use, and lack of vaginal lactobacilli; women who have never been sexually active are rarely affected ³⁵. The cause of the microbial alteration that precipitates bacterial vaginosis is not fully understood, and whether bacterial vaginosis results from acquisition of a single sexually transmitted pathogen is not known. Nonetheless, women with bacterial vaginosis are at increased risk for the acquisition of some STDs (e.g., HIV, N. gonorrhoeae, C. trachomatis, and HSV- 2), complications after gynecologic surgery, complications of pregnancy, and recurrence of bacterial vaginosis ³⁶. Bacterial vaginosis also increases the risk for HIV transmission to male sex partners ¹. Although bacterial vaginosis-associated bacteria can be found in the male genitalia, treatment of male sex partners has not been beneficial in preventing the recurrence of bacterial vaginosis ².

Bacterial vaginosis diagnosis

Before you see a doctor or nurse for a test:

• Don’t douche or use vaginal deodorant sprays. They might cover odors that can help your doctor diagnose bacterial vaginosis. They can also irritate your vagina.
• Make an appointment for a day when you do not have your period.

There are tests to find out if you have bacterial vaginosis. Your doctor or nurse takes a sample of vaginal discharge. Your doctor or nurse may then look at the sample under a microscope, use an in-office test, or send it to a lab to check for harmful bacteria. Your doctor or nurse may also see signs of bacterial vaginosis during an exam.

Bacterial vaginosis can be diagnosed by the use of clinical criteria (i.e., Amsel’s Diagnostic Criteria) ³⁷ or Gram stain. A Gram stain (considered the gold standard laboratory method for diagnosing bacterial vaginosis) is used to determine the relative concentration of lactobacilli (i.e., long Gram-positive rods), Gram-negative and Gram-variable rods and cocci (i.e., Gardnerella Vaginalis, Prevotella, Porphyromonas, and peptostreptococci), and curved Gram-negative rods (i.e., Mobiluncus) characteristic of bacterial vaginosis. Clinical criteria require three of the following symptoms or signs:

• homogeneous, thin, white discharge that smoothly coats the vaginal walls;
• clue cells (e.g., vaginal epithelial cells studded with adherent coccobacilli) on microscopic examination;
• pH of vaginal fluid >4.5; or
• a fishy odor of vaginal discharge before or after addition of 10% potassium hydroxide (i.e., the Whiff test).

Detection of three of these criteria has been correlated with results by Gram stain ³⁸. Other tests, including Affirm VP III (Becton Dickinson, Sparks, MD), a DNA hybridization probe test for high concentrations of Gardnerella Vaginalis, and the OSOM bacterial vaginosis Blue test (Sekisui Diagnostics, Framingham, MA), which detects vaginal fluid sialidase activity, have acceptable performance characteristics compared with Gram stain. Although a prolineaminopeptidase card test is available for the detection of elevated pH and trimethylamine, it has low sensitivity and specificity and therefore is not recommended. Polymerase chain reaction (PCR) has been used in research settings for the detection of a variety of organisms associated with bacterial vaginosis, but evaluation of its clinical utility is still underway. Detection of specific organisms might be predictive of bacterial vaginosis by polymerase chain reaction (PCR) ³⁹. Additional validation is needed before these tests can be recommended to diagnose bacterial vaginosis. Culture of Gardnerella Vaginalis is not recommended as a diagnostic tool because it is not specific. Cervical Pap tests have no clinical utility for the diagnosis of bacterial vaginosis because of their low sensitivity and specificity.

Bacterial vaginosis treatment

Treatment is recommended for women with symptoms. The established benefits of therapy in nonpregnant women are to relieve vaginal symptoms and signs of infection. Other potential benefits to treatment include reduction in the risk for acquiring Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, HIV, and herpes simplex type 2 ⁴⁰.

Bacterial vaginosis medication

Recommended antibiotics for bacterial vaginosis ⁵:

• Metronidazole 500 mg orally twice a day for 7 days
• OR Metronidazole gel 0.75%, one full applicator (5 g) intravaginally, once a day for 5 days
• OR Clindamycin cream 2%, one full applicator (5 g) intravaginally at bedtime for 7 days

Alcohol consumption should be avoided during treatment with nitroimidazoles. To reduce the possibility of a disulfiram-like reaction, abstinence from alcohol use should continue for 24 hours after completion of metronidazole. Clindamycin cream is oil-based and might weaken latex condoms and diaphragms for 5 days after use (refer to clindamycin product information for additional information).

Women should be advised to refrain from sexual activity or use condoms consistently and correctly during the treatment regimen. Douching might increase the risk for relapse, and no data support the use of douching for treatment or relief of symptoms.

Intravaginal clindamycin cream is preferred in case of allergy or intolerance to metronidazole or tinidazole. Intravaginal metronidazole gel can be considered for women who are not allergic to metronidazole but do not tolerate oral metronidazole.

Alternative bacterial vaginosis medicine ⁵:

• Tinidazole 2 g orally once daily for 2 days
• OR Tinidazole 1 g orally once daily for 5 days
• OR Clindamycin 300 mg orally twice daily for 7 days
• OR Clindamycin ovules 100 mg intravaginally once at bedtime for 3 days*

*Clindamycin ovules use an oleaginous base that might weaken latex or rubber products (e.g., condoms and vaginal contraceptive diaphragms). Use of such products within 72 hours following treatment with clindamycin ovules is not recommended.

Alcohol consumption should be avoided during treatment with nitroimidazoles. To reduce the possibility of a disulfiram-like reaction, abstinence from alcohol use should continue for 72 hours after completion of tinidazole.

Alternative regimens include several tinidazole regimens ⁴¹ or clindamycin (oral or intravaginal) ⁴². An additional regimen includes metronidazole (750-mg extended release tablets orally once daily for 7 days); however, data on the performance of this alternative regimen are limited.

Certain studies have evaluated the clinical and microbiologic efficacy of using intravaginal lactobacillus formulations to treat bacterial vaginosis and restore normal flora ⁴³. Overall, no studies support the addition of any available lactobacillus formulations or probiotic as an adjunctive or replacement therapy in women with bacterial vaginosis. Further research efforts to determine the role of these regimens in bacterial vaginosis treatment and prevention are ongoing.

Management of Sex Partners

Data from clinical trials indicate that a woman’s response to therapy and the likelihood of relapse or recurrence are not affected by treatment of her sex partner(s) ². Therefore, routine treatment of sex partners is not recommended.

Follow-Up

Follow-up visits are unnecessary if symptoms resolve ⁵. Because persistent or recurrent bacterial vaginosis is common, women should be advised to return for evaluation if symptoms recur ⁵. Detection of certain bacterial vaginosis-associated organisms has been associated with antimicrobial resistance and might be predictive of risk for subsequent treatment failure ⁴⁴. Limited data are available regarding optimal management strategies for women with persistent or recurrent bacterial vaginosis. Using a different recommended treatment regimen can be considered in women who have a recurrence; however, retreatment with the same recommended regimen is an acceptable approach for treating persistent or recurrent bacterial vaginosis after the first occurrence ⁴⁵. For women with multiple recurrences after completion of a recommended regimen, 0.75% metronidazole gel twice weekly for 4–6 months has been shown to reduce recurrences, although this benefit might not persist when suppressive therapy is discontinued ⁴⁶. Limited data suggest that an oral nitroimidazole (metronidazole or tinidazole 500 mg twice daily for 7 days) followed by intravaginal boric acid 600 mg daily for 21 days and then suppressive 0.75% metronidazole gel twice weekly for 4–6 months for those women in remission might be an option for women with recurrent bacterial vaginosis ⁴⁷. Monthly oral metronidazole 2g administered with fluconazole 150 mg has also been evaluated as suppressive therapy; this regimen reduced the incidence of bacterial vaginosis and promoted colonization with normal vaginal flora ⁴⁸.

HIV Infection

Bacterial vaginosis appears to recur with higher frequency in women who have HIV infection ⁴⁹. Women with HIV who have bacterial vaginosis should receive the same treatment regimen as those who do not have HIV infection.

1. Cohen CR, Lingappa JR, Baeten JM, et al. Bacterial vaginosis associated with increased risk of female-to-male HIV-1 transmission: a prospective cohort analysis among African couples. PLoS Med 2012;9:e1001251.[↩][↩]
2. Mehta SD. Systematic review of randomized trials of treatment of male sexual partners for improved bacteria vaginosis outcomes in women. Sex Transm Dis 2012;39:822–30.[↩][↩][↩]
3. Vaginitis: Diagnosis and Treatment. Am Fam Physician. 2018 Mar 1;97(5):321-329. https://www.aafp.org/afp/2018/0301/p321.html[↩][↩][↩][↩][↩][↩]
4. Bacterial Vaginosis – CDC Fact Sheet. https://www.cdc.gov/std/bv/stdfact-bacterial-vaginosis.htm[↩][↩]
5. Bacterial Vaginosis. 2015 Sexually Transmitted Diseases Treatment Guidelines. https://www.cdc.gov/std/tg2015/bv.htm[↩][↩][↩][↩][↩][↩][↩][↩]
6. Klebanoff, M.A., et al. (2010). Personal Hygienic Behaviors and Bacterial Vaginosis. Sex Transm Dis; 37(2):94-9.[↩]
7. Koumans, E.H., Sternberg, M., Bruce, C., McQuillan, G., Kendrick, J., Sutton, M., Markowitz, L. (2007). The Prevalence of Bacterial Vaginosis in the United States, 2001-2004; Associations with Symptoms, Sexual Behaviors, and Reproductive Health (link is external). Sexually Transmitted Diseases; 34(11): 864-869.[↩]
8. Ness, R.B., et al. (2003). Can known risk factors explain racial differences in the occurrence of bacterial vaginosis? (link is external) J Natl Med Assoc; 95:201–212.[↩]
9. Madden, T. et al. (2012). Risk of bacterial vaginosis in users of the intrauterine device: a longitudinal study. Sex Transm Dis; 39(3): 217-222.[↩]
10. Koumans EH, Sternberg M, Bruce C, McQuillan G, Kendrick J, Sutton M, Markowitz LE. The prevalence of bacterial vaginosis in the United States, 2001-2004; associations with symptoms, sexual behaviors, and reproductive health. Sex Transm Dis. 2007 Nov;34(11):864-9. https://journals.lww.com/stdjournal/Fulltext/2007/11000/The_Prevalence_of_Bacterial_Vaginosis_in_the.6.aspx[↩]
11. Money, D. (2005). The laboratory diagnosis of bacterial vaginosis. The Canadian Journal of Infectious Diseases and Medical Microbiology. 16, 77–79.[↩]
12. Bacterial Vaginosis – CDC Fact Sheet. https://www.cdc.gov/std/BV/STDFact-Bacterial-Vaginosis.htm[↩]
13. Hauth JC, Goldenberg RL, Andrews WW, et al. Reduced incidence of preterm delivery with metronidazole and erythromycin in women with bacterial vaginosis. N Engl J Med 1995;333:1732–6.[↩][↩]
14. Morales WJ, Schorr S, Albritton J. Effect of metronidazole in patients with preterm birth in preceding pregnancy and bacterial vaginosis: a placebo-controlled, double-blind study. Am J Obstet Gynecol 1994;171:345–9.[↩][↩]
15. Yudin MH, Landers DV, Meyn L, et al. Clinical and cervical cytokine response to treatment with oral or vaginal metronidazole for bacterial vaginosis during pregnancy: a randomized trial. Obstet Gynecol 2003;102:527–34.[↩]
16. Ugwumadu A, Reid F, Hay P, et al. Natural history of bacterial vaginosis and intermediate flora in pregnancy and effect of oral clindamycin. Obstet Gynecol 2004;104:114–9.[↩]
17. Burtin P, Taddio A, Ariburnu O, et al. Safety of metronidazole in pregnancy: a meta-analysis. Am J Obstet Gynecol 1995;172(2 Pt 1):525–9.[↩]
18. Piper JM, Mitchel EF, Ray WA. Prenatal use of metronidazole and birth-defects – no association. Obstet Gynecol 1993;82:348–52.[↩]
19. Lamont RF, Nhan-Chang CL, Sobel JD, et al. Treatment of abnormal vaginal flora in early pregnancy with clindamycin for the prevention of spontaneous preterm birth: a systematic review and metaanalysis. Am J Obstet Gynecol 2011;205:177–90.[↩]
20. Brocklehurst P, Gordon A, Heatley E, et al. Antibiotics for treating bacterial vaginosis in pregnancy. Cochrane Database Syst Rev 2013;1:CD000262.[↩]
21. Odendaal HJ, Popov I, Schoeman J, et al. Preterm labour—is bacterial vaginosis involved? South African Medical Journal 2002;92:231–4.[↩]
22. Carey JC, Klebanoff MA, Hauth JC, et al. Metronidazole to prevent preterm delivery in pregnant women with asymptomatic bacterial vaginosis. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units. N Engl J Med 2000;342:534–40.[↩]
23. Vermeulen GM, Bruinse HW. Prophylactic administration of clindamycin 2% vaginal cream to reduce the incidence of spontaneous preterm birth in women with an increased recurrence risk: a randomised placebo-controlled double-blind trial. Br J Obstet Gynaecol 1999;106:652–7.[↩][↩]
24. McDonald HM, O’Loughlin JA, Vigneswaran R, et al. Impact of metronidazole therapy on preterm birth in women with bacterial vaginosis flora (Gardnerella vaginalis): a randomised, placebo controlled trial. Br J Obstet Gynaecol 1997;104:1391–7.[↩]
25. Ugwumadu A, Manyonda I, Reid F, et al. Effect of early oral clindamycin on late miscarriage and preterm delivery in asymptomatic women with abnormal vaginal flora and bacterial vaginosis: a randomised controlled trial. Lancet 2003;361:983–8.[↩][↩]
26. Lamont RF, Duncan SL, Mandal D, et al. Intravaginal clindamycin to reduce preterm birth in women with abnormal genital tract flora. Obstet Gynecol 2003;101:516–22.[↩]
27. US Preventive Services Task Force. Screening for bacterial vaginosis in pregnancy to prevent preterm delivery: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2008;148:214–9.[↩]
28. Koss CA, Baras DC, Lane SD, et al. Investigation of metronidazole use during pregnancy and adverse birth outcomes. Antimicrob Agents Chemother 2012;56:4800–5.[↩]
29. Briggs GC, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation, 9th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2011.[↩][↩]
30. https://toxnet.nlm.nih.gov/newtoxnet/lactmed.htm[↩]
31. Erickson SH, Oppenheim GL, Smith GH. Metronidazole in breast milk. Obstet Gynecol 1981;57:48–50.[↩]
32. Golightly P, Kearney L. Metronidazole— is it safe to use with breastfeeding? United Kingdom National Health Service, UKMI;2012.[↩]
33. Bacterial Vaginosis. https://www.cdc.gov/std/tg2015/bv.htm[↩]
34. Koumans EH, Sternberg M, Bruce C, et al. The prevalence of bacterial vaginosis in the United States, 2001-2004: associations with symptoms, sexual behaviors, and reproductive health. Sex Transm Dis 2007;34:864–9.[↩]
35. Fethers KA, Fairley CK, Morton A, et al. Early sexual experiences and risk factors for bacterial vaginosis. J Infect Dis 2009;200:1662–70.[↩]
36. Laxmi U, Agrawal S, Raghunandan C, et al. Association of bacterial vaginosis with adverse fetomaternal outcome in women with spontaneous preterm labor: a prospective cohort study. J Matern Fetal Neonatal Med 2012;25:64–7.[↩]
37. Amsel R, Totten PA, Spiegel CA, et al. Nonspecific vaginitis. Diagnostic criteria and microbial and epidemiologic associations. Am J Med 1983;74:14–22.[↩]
38. Schwebke JR, Hillier SL, Sobel JD, et al. Validity of the vaginal gram stain for the diagnosis of bacterial vaginosis. Obstet Gynecol 1996;88(4 Pt 1):573–6.[↩]
39. Cartwright CP, Lembke BD, Ramachandran K, et al. Development and validation of a semiquantitative, multitarget PCR assay for diagnosis of bacterial vaginosis. J Clin Microbiol 2012;50:2321–9.[↩]
40. Brotman RM, Klebanoff MA, Nansel TR, et al. Bacterial vaginosis assessed by gram stain and diminished colonization resistance to incident gonococcal, chlamydial, and trichomonal genital infection. J Infect Dis 2010;202:1907–15.[↩]
41. Livengood CH, 3rd, Ferris DG, Wiesenfeld HC, et al. Effectiveness of two tinidazole regimens in treatment of bacterial vaginosis: a randomized controlled trial. Obstet Gynecol 2007;110(2 Pt 1):302–9.[↩]
42. Sobel J, Peipert JF, McGregor JA, et al. Efficacy of clindamycin vaginal ovule (3-day treatment) vs. clindamycin vaginal cream (7-day treatment) in bacterial vaginosis. Infect Dis Obstet Gynecol 2001;9:9–15.[↩]
43. Hemmerling A, Harrison W, Schroeder A, et al. Phase 2a study assessing colonization efficiency, safety, and acceptability of Lactobacillus crispatus CTV-05 in women with bacterial vaginosis. Sex Transm Dis 2010;37:745–50.[↩]
44. Nyirjesy P, McIntosh MJ, Steinmetz JI, et al. The effects of intravaginal clindamycin and metronidazole therapy on vaginal mobiluncus morphotypes in patients with bacterial vaginosis. Sex Transm Dis 2007;34:197–202.[↩]
45. Bunge KE, Beigi RH, Meyn LA, et al. The efficacy of retreatment with the same medication for early treatment failure of bacterial vaginosis. Sex Transm Dis 2009;36:711–3.[↩]
46. Sobel JD, Ferris D, Schwebke J, et al. Suppressive antibacterial therapy with 0.75% metronidazole vaginal gel to prevent recurrent bacterial vaginosis. Am J Obstet Gynecol 2006;194:1283–9.[↩]
47. Reichman O, Akins R, Sobel JD. Boric acid addition to suppressive antimicrobial therapy for recurrent bacterial vaginosis. Sex Transm Dis 2009;36:732–4.[↩]
48. McClelland RS, Richardson BA, Hassan WM, et al. Improvement of vaginal health for Kenyan women at risk for acquisition of human immunodeficiency virus type 1: results of a randomized trial. J Infect Dis 2008;197:1361–8.[↩]
49. Jamieson DJ, Duerr A, Klein RS, et al. Longitudinal analysis of bacterial vaginosis: findings from the HIV epidemiology research study. Obstet Gynecol 2001;98:656–63.[↩]