Bacterial vaginosis, sometimes referred to as BV, is the most common bacterial infection in women of childbearing age. Bacterial vaginosis occurs when there is an imbalance between “good” and “bad” bacteria in the vagina. Normally, about 95% of bacteria in the vagina are lactobacillus bacteria (“good” bacteria), which keep the vaginal pH level low and control the growth of “bad” bacteria. In women with BV, there are fewer lactobacillus bacteria than normal.
BV can be sexually transmitted, although some women get the infection without being sexually active. For this reason, BV is considered to be a sexually associated infection rather than a sexually transmitted infection. BV is most common among women who have sexual contact with other women. It does not appear to be an infection that is passed from a man to a woman.
Although it is still unclear why some women get the infection, we do know that BV cannot be spread from contact with a toilet seat, hot tub, swimming pool, or contaminated bedding. However, it can sometimes be spread by sharing sex toys.
According to The Centers for Disease Control (CDC), the prevalence in the United States is approximately 21.2 million (29% of women of childbearing age). It occurs in about 25% of pregnant women and about 60% of women who have a sexually-transmitted disease. African-American women and Mexican American women have higher incidence rates than white women (51%, 31%, and 23% respectively).
Although BV is not always sexually transmitted, the risk of infection is higher among women who have sex with multiple partners, who have a new partner, or who have sex without a condom. Douching can also be a contributing factor, since the antiseptic chemicals in the douche can kill off the good bacteria in the vagina.
Other things that can upset the balance of bacteria in the vagina are recent antibiotic use, pregnancy, poor diet, cigarette smoking, and vaginal products such as sprays, lubricants, and birth control devices.
People who have sexually transmitted infections such as HIV are more likely to also have BV.
More than half of women with BV do not notice any symptoms at all. When symptoms do occur, they may include an unusual discharge, painful urination, and itching or burning in the vaginal area. Some women experience a strong fishy odor, especially after sexual intercourse.
In most cases, bacterial vaginosis does not cause other health problems. However, in some cases it can lead to serious complications. During pregnancy, BV can increase the likelihood of premature rupture of the membranes (PROM) and preterm birth (a birth that takes place more than 3 weeks before the baby is due). Infected mothers have a higher risk of having babies with a low birth weight (less than 5.5 pounds). Infected mothers are also more likely to develop uterine infections after childbirth.
BV can facilitate the transmission of other sexually transmitted infections, especially chlamydia, gonorrhea, and HIV. In women who are HIV positive, there is a greater risk of passing the HIV virus to a sexual partner.
Women who have an invasive pelvic procedure such as a cesarean section, an abortion, or a hysterectomy are at greater risk of getting a pelvic infection such as pelvic inflammatory disease or endometritis.
After you describe your symptoms, your health care provider will do a pelvic examination and inspect your vagina for irritation and abnormal discharge. A sample of vaginal fluid will be examined under a microscope or sent to a lab for testing. In some cases, several drops of potassium hydroxide are added to the sample of vaginal discharge in order to see whether a fishy odor is produced. This is known as the “whiff test”.
To facilitate diagnosis, you should schedule your exam when you are not having your monthly period. Do not douche, use vaginal sprays, or use a tampon within 24 hours of your exam. Use condoms if you have sex within 24 hours of your exam.
BV will sometimes clear up on its own without treatment. However, getting treatment is important to avoid complications. Treatment may also reduce the risk for STDs.
BV can be treated with antibiotics, vaginal creams, and suppositories. The most common treatment is an oral medication called metronidazole (Flagyl, Metryl, Protostat). Although some physicians are hesitant to use metronidazole in women who are pregnant, the FDA has classified it as a Category B drug, which means that animal studies have shown no risk to the fetus. According to the CDC, metronidazole can be used even during the first trimester of pregnancy. In patients who drink alcohol, metronidazole can cause very unpleasant side effects including headaches, rapid heartbeat, abdominal cramps, and severe nausea and vomiting. To avoid these side effects, alcoholic beverages should be eliminated during treatment and for at least 3 days after treatment is complete.
A newer oral antibiotic – tinidazole (Tindamax) – has slightly fewer gastrointestinal side effects but has not been studied as extensively. It is classified as a Category C drug, which means that animal studies have shown risk to the fetus, but there have been no controlled studies in women.
Other treatments for BV include vaginal clindamycin cream (Cleocin) and metronidazole gel (Metrogel). For recurrent cases, the CDC is now recommending vaginally-administered boric acid in a gelatin capsule. Probiotics therapy – which attempts to boost the number of good bacteria in the vagina by eating yogurt and other foods containing lactobacilli – is gaining in popularity, especially as a way to prevent recurrences. However, further research is needed to determine the risks and benefits.
BV usually clears up in 2 or 3 days with antibiotics, but it is important to take all of the medicine prescribed to you (usually a 7-day regimen) even if your symptoms disappear. BV will often recur even after successful treatment. In fact, more than half of women have recurrent symptoms within 12 months.
In most cases, male sex partners of women diagnosed with BV do not need to be treated. However, BV may be transferred between female sex partners. Sexual intercourse should be avoided until treatment is complete.
Because BV can be transmitted during sexual activity, the most reliable way to prevent infection is to abstain from oral, vaginal, and anal sex or to have a mutually monogamous relationship with an uninfected sex partner. Latex condoms or dental dams can also reduce the risk of spreading the infection.
Douching should be avoided, since it can kill the good bacteria in the vagina. It is also advisable to avoid feminine hygiene sprays, fragranced soaps, and soaps with harsh chemical ingredients. Washing around the vagina and vulva should be minimized – once a day is usually enough.
In general, BV does not cause anything more than embarrassment, discomfort, and inconvenience. However, it is still important to consider prevention techniques such as mutual monogamy.
Source: Centers for Disease Control
Source: American Sexual Health Association
Source: Mayo Clinic