Lessons from Suppressive Therapy and Periodic Presumptive Treatment for Bacterial Vaginosis

Probiotics reduce the recurrence of asymptomatic bacterial vaginosis in Chinese women

Asymptomatic Bacterial Vaginosis(aBV)increases the risk of acquiring multiple sexually transmitted diseases, HPV, gynecologic complications and adverse reproductive outcomes, and is speculated to affect 10 ~ 35% of women. Without intervention, a significant proportion of aBV would progress. Metronidazole is the most widely used treatment for aBV, yet the main challenge has always been the high rate of recurrence. Probiotics may increase the cure rate and reduce the recurrence rate of symptomatic bacterial vaginosis (sBV), while no study has compared the efficacy of probiotics and metronidazole on treating aBV. This study aims to fill the gap in understanding the difference in efficacy of probiotics and metronidazole in treating aBV by a multicenter, randomized, controlled trial. Participants received either a 10-day intravaginal probiotic capsules or a 7-day oral metronidazole. Follow-up were performed at the end of the 1st, 2nd, and 4th week after completing therapy. Women cured by either method were followed up with three additional visits. The primary outcome was the difference of cure rates between the two groups. The secondary outcome was to evaluate the recurrence rates among patients who were successfully cured using either method. 358 participants received probiotics and another 358 participants received metronidazole. The cumulative cure rates at the end of the 1st, 2nd, and 4th week were higher in probiotics group compared to metronidazole group (OR 1.063, P = 0.715; OR 1.324, P = 0.083; OR 1.338, P = 0.071), while the differences were not statistically significant. Women cured (144 in probiotics and 123 in metronidazole) were followed up. The difference of cumulative recurrence rates between the two groups were statistically significant at the end of the 2nd, 3rd, and 4th month (OR 0.212, P = 0.000; OR 0.160, P = 0.000; OR 0.119, P = 0.000). Adverse events were similar in the two groups (8.3%, 9.6% OR 0.858; P = 0.584). No life-threatening or severe adverse events were reported. Probiotics emerge as a superior therapeutic option for aBV due to their comparable cure rates, lower recurrence rates, and minimal side effects. Chinese Clinical Trial Registry (ChiCTR1800019436, 11/11/2018 ).

Efficacy of Dequalinium Chloride vs Metronidazole for the Treatment of Bacterial Vaginosis: A Randomized Clinical Trial

Importance

Bacterial vaginosis (BV) is a common cause of vaginal infection. First-line treatments of BV are metronidazole and clindamycin. Due to the increase in antibiotic resistance, effective nonantibiotic treatments for BV are needed.

Objective

To examine whether dequalinium chloride, a broad-spectrum antiseptic, is noninferior to oral metronidazole for the treatment of BV.

Design, Setting, and Participants

This phase 4, multicenter, triple-blind, double-dummy, parallel, noninferiority randomized clinical trial was conducted from July 29, 2021, to August 25, 2022, with a 1-month follow-up. Participants were premenopausal women 18 years or older with BV from 11 gynecologic practices and 1 hospital in Poland, Slovakia, and the Czech.

Intervention

Patients were randomized to treatment with dequalinium chloride vaginal tablets (10 mg once daily for 6 days) or oral metronidazole (500 mg twice daily for 7 days). Double-dummy medication kits contained vaginal and oral tablets with placebo and active medication.

Main Outcomes and Measures

The main outcome was the noninferiority margin (of 15 percentage points) in the absolute difference in clinical cure rates between dequalinium chloride and metronidazole 7 to 11 days after start of treatment (visit 1). Noninferiority was met if the lower 95% CI for the difference in clinical cure rate was less than 15 percentage points at visit 1.

Results

A total of 147 women (mean [SD] age, 36.7 [9.0] years) were treated with dequalinium chloride (n = 72) or metronidazole (n = 75). The clinical cure rates at visit 1 were 64 of 69 (92.8%) for dequalinium chloride vs 69 of 74 (93.2%) for metronidazole in the intention-to-treat population, whereas in the per-protocol population, cure rates were 54 of 58 (93.1%) for dequalinium chloride vs 48 of 53 (90.6%) for metronidazole. The treatment differences of -0.5 percentage points (95% CI, -10.8 to 9.8 percentage points; P = .002) in the intention-to-treat population and 2.5 percentage points (95% CI, -9.4 to 14.4 percentage points; P = .001) in the per-protocol population confirmed the noninferiority of dequalinium chloride. The tolerability of dequalinium chloride was rated as very good by 30 of 50 patients (60.0%) but only by 21 of 54 (38.9%) for metronidazole. Three patients in the metronidazole group suspended treatment due to an adverse event.

Conclusions and Relevance

This randomized clinical trial showed that dequalinium chloride was not inferior to metronidazole for the treatment of BV. Dequalinium chloride had a similarly high cure rate but with better tolerability and fewer adverse events. With a similar efficacy to metronidazole and clindamycin, dequalinium chloride warrants consideration as first-line treatment for BV to help reduce antibiotic consumption.

Trial Registration

EudraCT: 2020-002489-15.

Epidemiologic Evidence on the Role of Lactobacillus iners in Sexually Transmitted Infections and Bacterial Vaginosis: A Series of Systematic Reviews and Meta-Analyses

ABSTRACT

Although Lactobacillus crispatus -dominated vaginal microbiotas are thought to protect against bacterial vaginosis (BV) and sexually transmitted infections, the role of Lactobacillus iners -dominated microbiotas is less clear. To better understand the impact of L. iners on common cervicovaginal infections, we conducted systematic reviews of the associations between L. iners compared with L. crispatus and 8 outcomes: Chlamydia trachomatis (Ct), BV, human papillomavirus, cervical dysplasia, human immunodeficiency virus, genital herpes, Trichomonas vaginalis , and Neisseria gonorrhoeae . On April 30, 2021, we searched PubMed, Embase, Cochrane Library, and Web of Science for epidemiologic studies of reproductive-age, nonpregnant, cisgender women that used marker gene sequencing to characterize vaginal microbiota composition and presented an effect estimate for the association between L. iners , compared with L. crispatus , and outcomes of interest. For outcomes with ≥3 eligible results presenting the same form of effect estimate, we conducted random-effects meta-analysis. The review protocol was registered prospectively (PROSPERO CRD42020214775). Six Ct studies were included in meta-analysis, which showed L. iners -dominated microbiotas were associated with 3.4-fold higher odds of Ct compared with L. crispatus -dominated microbiotas (95% confidence interval, 2.1-5.4). Three BV studies were included in meta-analysis, which indicated L. iners -dominated microbiotas were associated with 2.1-fold higher prevalence of BV compared with L. crispatus -dominated microbiotas (95% confidence interval, 0.9-4.9). Evidence was too sparse to perform meta-analysis for the remaining outcomes. L. iners -dominated vaginal microbiotas may be suboptimal compared with L. crispatus -dominated microbiotas for BV and Ct. These reviews highlight evidence gaps regarding the remaining outcomes and opportunities to improve epidemiologic rigor in vaginal microbiome science.

An Integrative Review of the Relationship Between Intrauterine Devices and Bacterial Vaginosis

OBJECTIVE

To examine the relationship between intrauterine devices (IUDs) and bacterial vaginosis (BV) through an integrative review of the current literature.

DATA SOURCES

CINAHL, MEDLINE, Health Source, Evidence-Based Medicine's Cochrane Central Registry of Controlled Trials, Embase, and Web of Science databases were searched.

STUDY SELECTION

Cross-sectional, case-control, cohort, quasi-experimental, and randomized controlled trials examining copper (Cu-IUD) and levonorgestrel (LNG-IUD) use in reproductive- age users with BV occurrence confirmed with Amsel's criteria or Nugent scoring were included. Articles included were published in the past 10 years.

DATA EXTRACTION

Fifteen studies met criteria, after an initial search identified 1,140 potential titles, and two reviewers assessed 62 full-text articles for inclusion.

DATA SYNTHESIS

Data were categorized into three groups: retrospective descriptive cross-sectional studies identifying point prevalence of BV among IUD users; prospective analytic studies examining BV incidence and prevalence among Cu-IUD users; and prospective analytic studies examining BV incidence and prevalence among LNG-IUD users.

CONCLUSION

Synthesis and comparison of studies were difficult because of disparate study designs, sample sizes, comparator groups, and inclusion criteria for individual studies. Synthesis of data from cross-sectional studies showed that all IUD users combined may have an increased point prevalence of BV compared with non-IUD users. These studies did not delineate LNG-IUDs from Cu-IUDs. Findings from cohort and experimental studies suggest a possible increase in BV occurrence among Cu-IUD users. Evidence is lacking to show an association between LNG-IUD use and BV.

Lactic acid gel versus metronidazole for recurrent bacterial vaginosis in women aged 16 years and over: the VITA RCT

Background

Bacterial vaginosis is a common and distressing condition associated with serious comorbidities. Antibiotic treatment is usually clinically effective in the short term, but recurrence is common and side effects can occur.

Objectives

The objective is to assess whether or not intravaginal lactic acid gel is clinically effective and cost-effective for treating recurrent bacterial vaginosis compared with oral metronidazole (Flagyl, Sanofi).

Design

This was an open-label, multicentre, parallel-arm, randomised (1 : 1) controlled trial.

Setting

This took place in one general practice and 19 sexual health centres in the UK.

Participants

Women aged ≥ 16 years with bacterial vaginosis symptoms and one or more episode(s) within the past 2 years took part.

Interventions

The interventions were 5 ml of intravaginal lactic acid gel taken once daily for 7 days (intervention) or 400-mg oral metronidazole tablets taken twice daily for 7 days (control).

Main outcome measures

The primary outcome was the resolution of bacterial vaginosis symptoms 14 days after randomisation. The secondary outcomes were time to first recurrence of symptoms; number of recurrences and treatment courses over 6 months; microbiological resolution on microscopy of vaginal smears at week 2; time to resolution of symptoms; tolerability, adherence and acceptability of the treatment; prevalence of concurrent sexually transmitted infections; quality of life; and cost-effectiveness.

Results

Recruitment stopped prior to reaching the target of 1900 participants on recommendation from the Data Monitoring Committee and Trial Steering Committee after a planned review of the results indicated that the research question had been answered. Overall, 518 participants were randomised and primary outcome data were available for 409 participants (79%; 204 in the metronidazole arm, 205 in the lactic acid gel arm). Participant-reported symptom resolution at week 2 was higher with metronidazole (143/204; 70%) than with lactic acid gel (97/205; 47%) (adjusted risk difference –23.2%, 95% confidence interval –32.3% to –14.0%). Recurrence in 6 months in a subset of participants who had initial resolution and were available for follow-up was similar across arms (metronidazole arm: 51/72, 71%; lactic acid gel arm: 32/46, 70%). A higher incidence of some side effects was reported with metronidazole than with lactic acid gel (nausea 32% vs. 8%; taste changes 18% vs. 1%; diarrhoea 20% vs. 6%, respectively). At week 2, the average cost per participant with resolved symptoms was £86.94 (metronidazole), compared with £147.00 (lactic acid gel). Some participants preferred using lactic acid gel even if they perceived it to be less effective than metronidazole.

Limitations

Loss to follow-up for collection of the primary outcome data was 21% and was similar in both arms. There is a risk of bias owing to missing outcome data at 3 and 6 months post treatment.

Conclusions

A higher initial response was seen with metronidazole than with lactic acid gel, but subsequent treatment failure was common with both. Lactic acid gel was less cost-effective than metronidazole. In general, women disliked taking repeated courses of metronidazole and preferred lactic acid gel, even when they were aware that it was less likely to provide symptom resolution. In the absence of effective curative therapy, further evaluation of non-antibiotic treatments to control the symptoms of recurrent bacterial vaginosis is required to improve quality of life for these patients. Further microbiological analysis of vaginal samples would be useful to identify additional factors affecting response to treatment.

Trial registration

Current Controlled Trials ISRCTN14161293.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 2. See the NIHR Journals Library website for further project information.

Protection and Risk: Male and Female Genital Microbiota and Sexually Transmitted Infections

Unique compositional and functional features of the cervicovaginal microbiota have been associated with protection against and risk for sexually transmitted infections (STI). In men, our knowledge of the interaction between the penile microbiota and STI is less developed. The current state of our understanding of these microbiota and their role in select STIs is briefly reviewed, along with strategies that leverage existing findings to manipulate genital microbiota and optimize protection against STIs. Finally, we focus on major research gaps and present a framework for future studies.