What is BV infection?
Bacterial vaginosis is the most common vaginal infection in women of childbearing age. Symptoms, when present, are usually mild. If the infection is not treated, BV may lead to complications including infertility, preterm labor, postoperative infections after gynecologic surgery and increased susceptibility to HIV and other sexually transmitted diseases. This explains why the Centers for Disease Control and Prevention recommend treating all cases of BV.
It is unclear if BV is sexually transmitted or simply more common in sexually active women. Infection occurs when the normal vaginal bacteria, lactobacilli, are replaced by anaerobic bacteria. These anaerobic bacteria produce amines, which create a fishy odor and discharge; however, 50 percent of affected women have no symptoms.
Most cases of BV are easily treated with oral or vaginal antibiotics. According to the 2002 Treatment Guidelines published by the CDC, the recommended medications are metronidazole or clindamycin. For approximately one out of five women, infections recur and may require repeat therapy with first-line antibiotics.
Medicine to treat BV
Metronidazole comes in two forms and is equally effective orally or as a vaginal gel. The recommended dosage is: oral metronidazole, 500 mg, twice a day for seven days; or metronidazole vaginal gel, inserted at bedtime for five days.
Metronidazole is more effective than the other first-line therapy, clindamycin cream, administered as 5 g, intravaginally, for seven days.
Metronidazole has an antabuse reaction, which means that if alcohol is consumed during treatment, severe nausea and vomiting occurs. Clindamycin cream may weaken condoms and make them ineffective.
Medication to treat BV: antibiotics
Second-line treatment uses the same medications, administered differently, and is not as effective as first-line therapy. These modifications may be made for the patient’s convenience or for those patients who cannot take metronidazole due to allergic reaction or other reasons.
The CDC recommends these alternative treatments:
- one 2 g dose of oral metronidazole;
- clindamycin 300 mg orally twice a day for seven days;
- or clindamycin 100 mg ovules intravaginally for three days.
Approximately 2-10 percent of people who take oral clindamycin may develop a secondary infection called pseudomembranous colitis, which causes diarrhea.
BV treatment during pregnancy
Only oral medication is recommended in pregnancy to cure the infection and potentially prevent pre-term labor and delivery. he CDC recommendation for pregnant patients is metronidazole 250 mg orally three times a day for seven days or clindamycin 300 mg orally twice a day for seven days.
Since BV is often asymptomatic, patients may be screened again for BV after treatment, especially if they are at increased risk for pre-term delivery.
Treatment Under Study
Because BV occurs when the number of normally occurring lactobacilli decline, studies are underway to test the effectiveness of administering vaginal lactobacilli as a treatment or prevention for BV.
A small study by Kingsley Anukaim and Emmanuel Osazuwa, et al, published in October 2006 in the journal Microbes and Infection, concluded that treatment with intravaginal lactobacilli was as effective as intravaginal Metrogel in treating BV.
The CDC reports that there is no evidence that either oral lactobacilli or vaginal douches treat BV. In addition, routine treatment of sex partners is not recommended.