Relationship of Specific Vaginal Bacteria and Bacterial Vaginosis Treatment Failure in Women Who Have Sex with Women

1 July 2008 | Volume 149 Issue 1 | Pages 20-28

Background: Bacterial vaginosis frequently persists after treatment. The role of newly defined bacterial vaginosis–associated bacteria (BVAB), which have a specificity for this condition of 97% or greater, has not been assessed.

Objective: To define risks for bacterial vaginosis persistence, including pretreatment detection of specific vaginal bacteria, among women reporting sex with women.

Design: Observational cohort study.

Setting: University-based research clinic.

Patients: 335 women age 16 to 29 years reporting sex with at least 1 woman in the past year. Participants were recruited through advertisements and provider referral.

Intervention: Bacterial vaginosis was treated with intravaginal metronidazole gel (0.75%), 37.5 mg nightly for 5 nights.

Measurements: Species-specific 16S recombinant DNA polymerase chain reaction assays targeting 17 bacterial species were applied to vaginal fluid obtained at baseline. Test of cure by clinical criteria and Gram stain analysis and repeated polymerase chain reaction assays of vaginal fluid were performed 1 month after treatment, and interim behaviors were assessed by using computer-assisted self-interview.

Results: Of 335 women, 24% of whom also reported sex with men within 3 months before enrollment, 131 (39%) had bacterial vaginosis. In the 120 (92%) women who returned for follow-up, the incidence of persistent bacterial vaginosis was 26% and was statistically significantly higher in women with baseline detection of 3 Clostridiales bacteria, designated as BVAB1 (risk ratio, 2.0 [95% CI, 1.1 to 4.0]), BVAB2 (risk ratio, 8.7 [CI, 2.5 to ]), or BVAB3 (risk ratio, 3.1 [CI, 1.7 to 5.8]); Peptoniphilus lacrimalis (risk ratio, 3.5 [CI, 1.6 to 15.5]); and Megasphaera phylotype 2 (risk ratio, 3.4 [CI, 1.4 to 5.5]). Persistence was lower with treatment adherence (risk ratio, 0.4 [0.2 to 0.9]). Detection of these bacteria at the test-of-cure visit was associated with persistence, whereas posttreatment sexual activity was not.

Limitations: Findings may not be generalizable to women who have sex only with men, or to women whose bacterial vaginosis is treated with oral antibiotics. The study may be too small and may involve a population that is too highly selected to draw definitive conclusions about associations of persistent infection with posttreatment sexual behaviors.

Conclusion: Persistent bacterial vaginosis is associated with several bacteria in the Clostridiales order, Megasphaera phylotype 2, and P. lacrimalis, suggesting that vaginal microbiology at diagnosis may determine risk for antibiotic failure.

Editors' Notes Context Bacterial vaginosis, a condition that is particularly common among women who have sex with women, is an overgrowth of anaerobic bacteria and depletion of normally occurring lactobacilli. Bacterial vaginosis persists or recurs in 11% to 29% of women at 1 month after treatment. Contribution This study identified that the presence of specific vaginal bacteria at baseline (Clostridia BVAB1, BVAB2, or BVAB3; Peptoniphilus lacrimalis; or Megasphaera phylotype 2) and lower adherence to treatment were the only factors associated with persistence of bacterial vaginosis 1 month after treatment among women who have sex with women. Caution The results might not apply to women who have sex only with men. —The Editors

 

Author and Article Information

From the University of Washington and the Fred Hutchinson Cancer Research Center, Seattle, Washington.

Acknowledgment: The authors thank the study staff, including Susan Heideke, Nancy Dorn, Lauren Asaba, and Dana Varon; Kathy Agnew for performance of Gram staining of vaginal fluid; James Hughes for valuable statistical insights; and the women who participated in the study. 3M Pharmaceuticals (St. Paul, Minnesota) provided vaginal metronidazole (Metrogel vaginal, 0.75%) for some participants.

Grant Support: By the National Institute of Allergy and Infectious Diseases (grants RO1 AI052228 [Dr. Marrazzo] and RO3 AI053250 and RO1 AI061628 [Dr. Fredricks]).

Potential Financial Conflicts of Interest: Consultancies: J.M. Marrazzo (K-V Pharmaceuticals, Mission Pharmacal). Honoraria: J.M. Marrazzo (3M).

Reproducible Research Statement: Study protocol: Available by contacting Dr. Marrazzo (e-mail, jmm2{at}u.washington.edu). Statistical code: Available by contacting Ms. Thomas (e-mail, kkt{at}u.washington.edu). Data set: Not available.

Requests for Single Reprints: Jeanne Marrazzo, MD, MPH, Harborview Medical Center, Mailbox 359931, 325 Ninth Avenue, Seattle, WA 98104; e-mail, jmm2{at}u.washington.edu.

Current Author Addresses: Dr. Marrazzo, Ms. Thomas, and Ms. Ringwood: Harborview Medical Center, Division of Infectious Diseases, 325 Ninth Avenue, Mailbox 359931, Seattle, WA 98104.

Ms. Fiedler and Dr. Fredricks: Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, D3-100, Box 19024, Seattle, WA 98109-1024.

Author Contributions: Conception and design: J.M. Marrazzo, D.N. Fredricks.

Analysis and interpretation of the data: J.M. Marrazzo, K.K. Thomas, D.N. Fredricks.

Drafting of the article: J.M. Marrazzo.

Critical revision of the article for important intellectual content: J.M. Marrazzo, K.K. Thomas, D.N. Fredricks.

Final approval of the article: J.M. Marrazzo, K.K. Thomas, T.L. Fiedler, K. Ringwood, D.N. Fredricks.

Provision of study materials or patients: J.M. Marrazzo.

Statistical expertise: J.M. Marrazzo, K.K. Thomas.

Obtaining of funding: J.M. Marrazzo, D.N. Fredricks.

Administrative, technical, or logistic support: K. Ringwood.

Collection and assembly of data: T.L. Fiedler, K. Ringwood.