Pathogenesis of Bacterial Vaginosis in Women Who Have Sex With Women

January 3, 2019 updated by: Dr. Christina Muzny, University of Alabama at Birmingham
The objectives of this study are to: (1) use cultivation-independent molecular methods to determine the sequence of microbiological events culminating in bacterial vaginosis (BV) among sexually active African American women who have sex with women (AAWSW) and (2) determine if specific Gardnerella vaginalis oligotypes are associated with the development of BV among sexually active AAWSW.

Study Overview

Status

Completed

Conditions

Detailed Description

Bacterial vaginosis (BV) is the most common cause of vaginal discharge in the U.S. It is associated with adverse outcomes including preterm birth, pelvic inflammatory disease, and increased risk of acquisition and transmission of sexually transmitted infections (STIs), including HIV. Microbiologically, BV is characterized by depletion of lactobacilli that comprise the normal vaginal flora and increases in facultative (Gardnerella vaginalis; GV) and strict anaerobes.

Three out of four Amsel criteria are necessary for the clinical diagnosis of BV and include (1) homogeneous, thin, grayish-white vaginal discharge, (2) vaginal pH >4.5, (3) positive whiff-amine test, and (4) clue cells present on a wet mount of vaginal fluid. BV diagnosis, however, is based most rigorously on Nugent scoring of a Gram stain of vaginal secretions. Optimal vaginal flora, indicative of a predominance of lactobacilli, is represented by a Nugent score of 0-3. Abnormal vaginal flora includes not only what is currently defined as BV (Nugent score 7-10) but also what is referred to as intermediate flora (Nugent score 4-6). For reasons not well understood, BV is very common among women who have sex with women (WSW), perhaps more so than among heterosexual women. Risks for prevalent BV among WSW have included higher numbers of lifetime female sexual partners, shared use of vaginally inserted sex toys, and oral-anal sex. In addition, WSW in monogamous sexual partnerships have a high concordance for the presence or absence of BV. These data support the hypothesis that BV is sexually transmitted.

It is well accepted that BV is caused by a synergistic relationship between a large number of microorganisms including GV and other anaerobics (i.e. BV-associated bacteria; BVAB) however the trigger which initiates these alterations is debated. It is unknown whether BV results from acquisition of GV as the "founder" organism which subsequently leads to the complex changes in the vaginal microbiota associated with BV or whether BV is transmitted as a polymicrobial consortium. GV, as a facultative anaerobe, may be better able to tolerate the high oxidation-reduction (redox) potential of the healthy vaginal microbiome, unlike strict anaerobes. Similar to facultative anaerobes involved in the initiation of oral disease, it is possible that GV, through its metabolic pathways and ability to form a biofilm (perhaps influenced by specific oligotypes), creates a lower redox potential in the vaginal microbiome. This alteration would then cause a marked decrease in lactobacilli and an increase in other BVAB that are normally present in very low concentrations, leading to the BV syndrome. Determining the exact etiology of the agent(s) causing a shift from optimal to abnormal vaginal flora and BV is vital for appropriate treatment and prevention of adverse outcomes. With increasing use of molecular methods, identification of vaginal microorganisms (some uncultivable) to the species level in women with BV has become more feasible. This study will seek to further investigate BV pathogenesis. We hypothesize that sexual exposure to Gardnerella vaginalis is the inciting event leading to the complex changes in vaginal flora associated with BV. If Gardnerella vaginalis is the initial insult, then its appearance and establishment in the vaginal microbiome will be seen in women who develop incident BV prior to increases in other BV-associated bacteria.

Only African American women will be enrolled in this protocol as differences in the composition of vaginal microbial communities of women with and without BV of different racial and ethnic groups have been noted which could confound the results of this study.

Study Type

Observational

Enrollment (Actual)

42

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35294
        • University of Alabama at Birmingham

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 45 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

Sexually active African American women who have sex with women with normal vaginal flora at baseline (determined based on 0/4 Amsel criteria and a normal Nugent score of 0-3 with no Gardnerella vaginalis morphotypes noted on vaginal Gram stain) will be followed prospectively over a 90 day time period for the development of incident BV.

Description

Screening Inclusion Criteria:

  1. African American race
  2. Female Gender
  3. Age 18-45 years
  4. History of sexual activity (oral, vaginal, and/or anal) with a female sexual partner during the past 12 months
  5. Current female sexual partner
  6. English speaking
  7. Ability to give written informed consent

Screening Exclusion Criteria:

  1. Use of antimicrobials (oral and/or vaginal) within the past 14 days
  2. Known HIV
  3. Known pregnancy
  4. Currently on menstrual period

Enrollment Inclusion Criteria:

  1. No Amsel criteria (i.e. patient currently asymptomatic from vaginal discharge standpoint, has normal vaginal pH, negative whiff test, and no clue cells on saline microscopy)
  2. Nugent score of 0-3 with no Gardnerella vaginalis morphotypes noted on Gram stain

Enrollment Exclusion Criteria:

  1. Presence of current vaginal infections (i.e. trichomoniasis or symptomatic vaginal yeast infection)

  2. Pregnancy

    • Reasons for Subsequent Participant Discontinuation after Initial Enrollment**:

(1) Duplicate Nugent score reading > 3 (2) Concurrent trichomonas diagnosis - as determined by nucleic acid amplification testing results

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Development of incident BV
Time Frame: 90 days
Based on 3 consecutive days of Nugent score readings of 7-10 (vaginal Gram stain result)
90 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Development of vaginal symptoms
Time Frame: 90 days
vaginal discharge, odor, itch based on participant daily diary information (study questionnaire)
90 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Alabama at Birmingham

Collaborators

National Institute of Allergy and Infectious Diseases (NIAID)
Louisiana State University Health Sciences Center in New Orleans
University of Mississippi Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2014

Primary Completion (ACTUAL)

January 1, 2019

Study Completion (ACTUAL)

January 1, 2019

Study Registration Dates

First Submitted

October 20, 2014

First Submitted That Met QC Criteria

October 20, 2014

First Posted (ESTIMATE)

October 22, 2014

Study Record Updates

Last Update Posted (ACTUAL)

January 7, 2019

Last Update Submitted That Met QC Criteria

January 3, 2019

Last Verified

January 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • F131127001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified data will be shared with statisticians at the University of Mississippi Medical center for statistical analysis.

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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