Bacterial Vaginosis (BV)

Vaginal discharge due to bacterial vaginosis is yellow-green or gray, thin, and malodorous, usually with a fishy odor that often becomes stronger when the discharge is more alkaline—after coitus and during menses.

Pruritus, irritation, erythema, and edema are not common.

For bacterial vaginosis to be diagnosed, 3 of 4 criteria (Amsel criteria) must be present:

Clue cells (bacteria adhering to epithelial cells and sometimes obscuring their cell margins) are identified by microscopic examination of a saline wet mount.

Presence of white blood cells on a saline wet mount suggests a concomitant infection (possibly trichomonal, gonorrheal, or chlamydial cervicitis Cervicitis Cervicitis is infectious or noninfectious inflammation of the cervix. Findings may include cervical or vaginal discharge and cervical erythema and friability. Diagnosis is with tests for cervical... read more ) and the need for additional testing.

NAATs are commercially available for clinical use (1–4 Diagnosis references Bacterial vaginosis is a dysbiosis, a complex alteration of vaginal flora, in which lactobacilli decrease and anaerobic pathogens overgrow. Symptoms include a yellow-green or gray, thin, malodorous... read more ). If microscopy is unavailable, the diagnosis is inconclusive, or the patient remains symptomatic, a NAAT should be considered.

The following treatments for bacterial vaginosis are equally effective (see CDC: Sexually Transmitted Infections Treatment Guidelines, 2021):

For topical treatments, metronidazole is preferred; clindamycin is an alternative option.

Oral metronidazole is the treatment of choice for patients who are not pregnant. For pregnant patients, topical regimens are preferred because systemic effects are possible with oral medications.

Women treated with clindamycin cream should not use latex products (ie, condoms or diaphragms) for contraception because the cream weakens latex.

Secnidazole 2 g orally once is another option for treating bacterial vaginosis (1 Treatment references Bacterial vaginosis is a dysbiosis, a complex alteration of vaginal flora, in which lactobacilli decrease and anaerobic pathogens overgrow. Symptoms include a yellow-green or gray, thin, malodorous... read more , 2 Treatment references Bacterial vaginosis is a dysbiosis, a complex alteration of vaginal flora, in which lactobacilli decrease and anaerobic pathogens overgrow. Symptoms include a yellow-green or gray, thin, malodorous... read more ). Because only one dose is needed, secnidazole may improve patient compliance.

Treatment of sex partners is not recommended.

For vaginitis during the 1st trimester of pregnancy, metronidazole vaginal gel should be used, although treatment during pregnancy has not been shown to lower the risk of pregnancy complications. To prevent endometritis, clinicians may give oral metronidazole prophylactically before elective abortion to all patients or only to those who test positive for bacterial vaginosis.

When treated, symptomatic bacterial vaginosis usually resolves in a few days but commonly recurs. If it recurs often (current infection and at least 2 previous episodes within the previous 12 months), ongoing suppressive antibiotics may be required. Suppressive therapy using the metronidazole gel 2 times a week for 16 weeks may be considered in patients with recurrent bacterial vaginosis (3 Treatment references Bacterial vaginosis is a dysbiosis, a complex alteration of vaginal flora, in which lactobacilli decrease and anaerobic pathogens overgrow. Symptoms include a yellow-green or gray, thin, malodorous... read more ).