Warning:

This document is being maintained for historical purposes, but is now out of date. To view current guidelines please visit:

• STD Treatment Guidelines   at http://www.cdc.gov/STD/treatment

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1993 Sexually Transmitted Diseases Treatment Guidelines

09/24/1993

SUGGESTED CITATION
Centers for Disease Control and Prevention. 1993 Sexually
transmitted diseases treatment guidelines. MMWR 1993;42(No. RR-14):
{inclusive page numbers}.

CIO Responsible for this publication:
National Center for Prevention Services,
Division of Sexually Transmitted Diseases and HIV Prevention

Bacterial Vaginosis
     
     BV is a clinical syndrome resulting from replacement of the
normal H2O2-producing Lactobacillus spp in the vagina with high
concentrations of anaerobic bacteria (e.g., Bacteroides spp,
Mobiluncus spp), G. vaginalis, and Mycoplasma hominis. This
condition is the most prevalent cause of vaginal discharge or
malodor. However, half the women who meet clinical criteria for BV
have no symptoms. The cause of the microbial alteration is not
fully understood. Although BV is associated with sexual activity in
that women who have never been sexually active are rarely affected
and acquisition of BV is associated with having multiple sex
partners, BV is not considered exclusively an STD. Treatment of the
male sex partner has not been found beneficial in preventing the
recurrence of BV.

Diagnostic Considerations
     BV may 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 adheres
     to the vaginal walls;

--   The presence of clue cells on microscopic examination;

--   pH of vaginal fluid greater than 4.5;

--   A fishy odor of vaginal discharge before or after addition of
     10% KOH (whiff test).

     When 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. G. vaginalis can be
isolated from vaginal cultures among half of normal women.

Treatment
     The principal goal of therapy is to relieve vaginal symptoms
and signs. Therefore, only women with symptomatic disease require
treatment. Because male sex partners of women with BV are not
symptomatic, and because treatment of male partners has not been
shown to alter either the clinical course of BV in women during
treatment or the relapse/reinfection rate, preventing transmission
to men is not a goal of therapy.

     Many bacterial flora characterizing BV have been recovered
from the endometrium or salpinx of women with PID. BV has been
associated with endometritis, PID, or vaginal cuff cellulitis
following invasive procedures such as endometrial biopsy,
hysterectomy, hysterosalpingography, placement of IUD, caesarian
section, or uterine curettage. A randomized controlled trial found
that treatment of BV with metronidazole substantially reduced
post-abortion PID. Based on these data, it may be reasonable to
consider treatment of BV (symptomatic or asymptomatic) before
performing surgical abortion procedures. However, more data are
needed to consider treatment of asymptomatic patients with BV when
performing other invasive procedures.

Recommended Regimen -
     Metronidazole 500 mg orally 2 times a day for 7 days.

NOTE: Patients should be advised to avoid using alcohol during
treatment with metronidazole and for 24 hours thereafter.
Alternative Regimens

     Metronidazole 2 g orally in a single dose.

     The following alternative regimens have been effective in
clinical trials, although experience with these regimens is
limited.

     Clindamycin cream, 2%, one full applicator (5 g)
     intravaginally at bedtime for 7 days;
                           or
     Metronidazole gel, 0.75%, one full applicator (5 g)
     intravaginally, 2 times a day for 5 days;
                           or
     Clindamycin 300 mg orally 2 times a day for 7 days.

     Oral metronidazole has been shown in numerous studies to be
efficacious for the treatment of BV, resulting in relief of
symptoms and improvement in clinical course and flora disturbances.
Based on efficacy data from four randomized-controlled trials, the
overall cure rates are 95% for the 7-day regimen and 84% for the 2
g single-dose regimen.

     Some health-care providers remain concerned about the
possibility of metronidazole mutagenicity, which has been suggested
by experiments on animals using extremely high and prolonged doses.
However, there is no evidence for mutagenicity in humans. Some
health-care providers prefer the intravaginal route because of lack
of systemic side effects such as mild-to-moderate gastrointestinal
upset and unpleasant taste (mean peak serum concentrations of
metronidazole following intravaginal administration are less than
2% those of standard 500 mg oral doses and mean bioavailability of
clindamycin cream is about 4%).

Follow-Up
     Follow-up visits are not necessary if symptoms resolve.
Recurrence of BV is common. The alternative treatment regimens
suitable for BV treatment may be used for treatment of recurrent
disease. No long-term maintenance regimen with any therapeutic
agent is currently available.

Management of Sex Partners
     Treatment of sex partners in clinical trials has not
influenced the woman's response to therapy, nor has it influenced
the relapse or recurrence rate. Therefore, routine treatment of sex
partners is not recommended.

Special Considerations

Allergy or Intolerance to the Recommended Therapy
     Clindamycin cream 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 -
     Because metronidazole is contraindicated during the first
trimester of pregnancy, clindamycin vaginal cream is the preferred
treatment for BV during the first trimester of pregnancy
(clindamycin cream is recommended instead of oral clindamycin
because of the general desire to limit the exposure of the fetus to
medication). During the second and third trimesters of pregnancy,
oral metronidazole can be used, although the vaginal metronidazole
gel or clindamycin cream may be preferable.

     BV has been associated with adverse outcomes of pregnancy
(e.g., premature rupture of the membranes, preterm labor, preterm
delivery), and the organisms found in increased concentration in BV
are also commonly present in postpartum or post-caesarean
endometritis. Whether treatment of BV among pregnant women would
reduce the risk of adverse pregnancy outcomes is unknown;
randomized controlled trials have not been conducted.

HIV infection -
     Persons with HIV and BV should receive the same treatment as
persons without HIV.

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