US Centers For Disease Control
2002 Guidelines
Treatment of Bacterial Vaginosis
BV is a clinical syndrome resulting from replacement of the normal H2O2-producing Lactobacillus sp. in the vagina with high concentrations of anaerobic bacteria (e.g., Prevotella sp. and Mobiluncus sp.), G. vaginalis, and Mycoplasma hominis. BV is the most prevalent cause of vaginal discharge or malodor; however, up to 50% of women with BV may not report symptoms of BV. The cause of the microbial alteration is not fully understood. BV is associated with having multiple sex partners, douching, and lack of vaginal lactobacilli; it is unclear whether BV results from acquisition of a sexually transmitted pathogen. Women who have never been sexually active are rarely affected. Treatment of the male sex partner has not been beneficial in preventing the recurrence of BV.
Diagnostic Considerations
BV can be diagnosed by the use of clinical or Gram-stain criteria. Clinical criteria require three of the following symptoms or signs:
·
* A homogeneous, white, noninflammatory discharge that smoothly coats the
vaginal walls;
·* the presence of clue cells on microscopic examination;
·* a pH of vaginal fluid >4.5; and
·* a fishy odor of vaginal discharge before or after addition of 10% KOH
(i.e., the whiff test).
When a Gram stain is used, determining the relative concentration of the bacterial morphotypes characteristic of the altered flora of BV is an acceptable laboratory method for diagnosing BV. Culture of G. vaginalis is not recommended as a diagnostic tool because it is not specific. However, a DNA probe based test for high concentrations of G. vaginalis (Affirm VP III, manufactured by Becton Dickinson, Sparks, Maryland) may have clinical utility. Cervical Pap tests have limited clinical utility for the diagnosis of BV because of low sensitivity. Other commercially available tests that may be useful for the diagnosis of BV include a card test for the detection of elevated pH and trimethylamine (FemExam® test card, manufactured by Cooper Surgical, Shelton, Connecticut) and prolineaminopeptidase (Pi p Activity TestCard, manufactured by Litmus Concepts, Inc., Santa Clara, California).
Treatment
The established benefits of therapy for BV in non-pregnant women are to a) relieve vaginal symptoms and signs of infection and b) reduce the risk for infectious complications after abortion or hysterectomy. Other potential benefits include the reduction of other infectious complications (e.g., HIV and other STDs). All women who have symptomatic disease require treatment.
BV during pregnancy is associated with adverse pregnancy outcomes, including premature rupture of the membranes, preterm labor, preterm birth, and postpartum endometritis. The established benefit of therapy for BV in pregnant women is to relieve vaginal symptoms and signs of infection. Additional potential benefits of therapy include a) reducing the risk for infectious complications associated with BV during pregnancy and b) reducing the risk for other infections (e.g., other STDs or HIV). The results of several investigations indicate that treatment of pregnant women who have BV and who are at high risk for preterm delivery (i.e., those who previously delivered a premature infant) may reduce the risk for prematurity (52--54). Therefore, high-risk pregnant women who have asymptomatic BV may be evaluated for treatment.
The bacterial flora that characterizes BV have been recovered from the endometria and salpinges of women who have PID. BV has been associated with endometritis, PID, and vaginal cuff cellulitis after invasive procedures, including endometrial biopsy, hysterectomy, hysterosalpingography, placement of an IUD, cesarean section, and uterine curettage. The results of two randomized controlled trials indicated that treatment of BV with metronidazole substantially reduced postabortion PID (55,56). Three trials that evaluated the use of anaerobic antimicrobial coverage (metronidazole) for routine operative prophylaxis before abortion and seven trials that evaluated this additional coverage for women undergoing hysterectomy found a substantial reduction (range: 10%--75%) in post-operative infectious complications (57--66). Because of the increased risk for postoperative infectious complications associated with BV, some specialists recommend that before performing surgical abortion or hysterectomy, providers screen and treat women with BV in addition to providing routine prophylaxis. However, more information is needed before recommending treatment of asymptomatic BV before other invasive procedures.
Recommended Regimens
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.
NOTE: Patients should be advised to avoid consuming alcohol during treatment with metronidazole and for 24 hours thereafter. Clindamycin cream and ovules are oil-based and might weaken latex condoms and diaphragms. Refer to condom product labeling for additional information.
The recommended metronidazole regimens are equally efficacious. The vaginal clindamycin cream appears less efficacious than the metronidazole regimens. The alternative regimens have lower efficacy for BV.
Alternative Regimens
Metronidazole 2 g orally in a single dose,
OR
Clindamycin 300 mg orally twice a day for 7 days,
OR
Clindamycin ovules 100 g intravaginally once at bedtime for 3 days.
One randomized trial evaluating the clinical equivalency of intravaginal metronidazole gel 0.75% once daily versus twice daily found similar cure rates 1 month after therapy (67). One randomized trial that evaluated the equivalency of clindamycin cream and clindamycin ovules found that cure rates did not differ significantly (68). Metronidazole 2 g single-dose therapy is an alternative regimen because of its lower efficacy for treatment of BV. Although FDA has approved metronidazole 750-mg extended release tablets once daily for 7 days, no data have been published on the clinical equivalency of this regimen with other regimens.
Studies are currently underway to evaluate the efficacy of vaginal lactobacilli suppositories in addition to oral metronidazole for the treatment of BV. No data support the use of non-vaginal lactobacilli or douching for the treatment of BV.
Follow-Up
Follow-up visits are unnecessary if symptoms resolve. Because recurrence of BV is not unusual, women should be advised to return for additional therapy if symptoms recur. Another recommended treatment regimen may be used to treat recurrent disease. No long-term maintenance regimen with any therapeutic agent is recommended.
Management of Sex Partners
The results of 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) (69--71). Therefore, routine treatment of sex partners is not recommended.
Special Considerations
Allergy or Intolerance to the Recommended Therapy
Clindamycin cream or oral clindamycin is preferred in case of allergy or intolerance to metronidazole. Metronidazole gel can be considered for patients who do not tolerate systemic metronidazole, but patients allergic to oral metronidazole should not be administered metronidazole vaginally.
Pregnancy
All symptomatic pregnant women should be tested and treated. BV has been associated with adverse pregnancy outcomes (e.g., premature rupture of the membranes, chorioamnionitis, preterm labor, preterm birth, postpartum endometritis, and post-cesarean wound infection). Some specialists prefer using systemic therapy to treat possible subclinical upper genital tract infections among women at low risk for preterm delivery (i.e., those who have no history of delivering an infant before term). Existing data do not support the use of topical agents during pregnancy. Evidence from three trials suggests an increase in adverse events (e.g., prematurity and neonatal infections), particularly in newborns, after use of clindamycin cream (72--74). Multiple studies and meta-analyses have not demonstrated a consistent association between metronidazole use during pregnancy and teratogenic or mutagenic effects in newborns (75--77).
Recommended Regimens During Pregnancy
Metronidazole 250 mg orally three times a day for 7 days
OR
Clindamycin 300 mg orally twice a day for 7 days.
Because treatment of BV in asymptomatic pregnant women at high risk for preterm delivery (i.e., those who have previously delivered a premature infant) with a recommended regimen has reduced preterm delivery in three of four randomized controlled trials (52--54,78), some specialists recommend the screening and treatment of these women. However, the optimal treatment regimens have not been established. The screening (if conducted) and treatment should be performed at the first prenatal visit.
The two trials that examined the use of metronidazole during pregnancy used the 250-mg regimen; the recommended regimen for BV in nonpregnant women is 500 mg twice daily. Some specialists also recommend this higher dose for treatment of pregnant women. In one published study, women with BV were treated at 19 weeks with a regimen of an initial dose of 2 g, followed by a 2-g dose 2 days later; the regimen was repeated 4 weeks later (78). This regimen was not effective in reducing preterm birth in any group of women.
Data are conflicting regarding whether treatment of asymptomatic pregnant women who are at low risk for preterm delivery reduces adverse outcomes of pregnancy. Several unpublished trials have evaluated screening and treatment for BV among asymptomatic low-risk pregnant women in the first or early second trimester. One trial, using oral clindamycin, demonstrated a reduction in spontaneous preterm birth; another indicated a reduction in postpartum infectious complications (79).
Follow-Up of Pregnant Women
Treatment of BV in asymptomatic pregnant women who are at high risk for preterm delivery might prevent adverse pregnancy outcomes. Therefore, a follow-up evaluation 1 month after completion of treatment should be considered to evaluate whether therapy was effective.
HIV Infection
Patients who have BV and also are infected with HIV should receive the same treatment regimen as those who are HIV-negative.
For More Information contact the CDC
