The epidemiology of bacterial vaginosis

A Clinicopathological Diagnostic and Therapeutic Approach to Cytolytic Vaginosis: An Extremely Rare Entity that may Mimic Vulvovaginal Candidiasis

Objectives:

Cytolytic vaginosis is a very rare entity that may be clinically misdiagnosed as vulvovaginal candidiasis. The aim of this study was to determine the incidence of cytolytic vaginosis in patients displaying symptoms similar to vulvovaginal candidiasis and to develop a clinicopathological diagnostic and therapeutic approach.

Materials and Methods:

In total, 3000 cervical smear samples were evaluated at our center between 2015 and 2018. Patients whose PAP smears demonstrated significant epithelial cytolysis, naked nuclei, excessive increase in lactobacilli population, absent or minimal neutrophils and no microorganisms were subjected to a symptom assessment questionnaire and had their vaginal pHs measured. They were classified into two groups according to their complaints, symptoms and vaginal pHs: Cytolytic vaginosis and Asymptomatic intravaginal lactobacillus overgrowth. A standardized NaHCO3 Sitz bath therapy was applied to the cytolytic vaginosis group.

Results:

Fifty-three of the patients (1.7%) were diagnosed as cytolytic vaginosis. After Sitz bath therapy, there was a statistically significant decrease in the cytolysis and lactobacillus scores of the patients. Vaginal discharge of 43 (81%) patients ceased completely while that of the remaining 10 (19%) patients decreased after the therapy. The improvement was statistically significant (P < 0.001). There was a complete resolution in 28 (96%) patients with severe; and in 21 (94%) patients with intermediate vaginal discomfort, after the therapy. Dyspareunia was resolved in 35 (97%) patients (P < 0.001).

Conclusion:

Cytolytic vaginosis is a rare entity that can be diagnosed with the help of cytopathology and has a therapy based on the modulation microbiota by decreasing the vaginal pH.

Treatment and Management of Bacterial Vaginosis in Pregnancy: Current and Future Perspectives

Bacterial vaginosis accounts for the majority of cases of vaginal discharge and has been consistently linked to an increased risk of preterm delivery. Bacterial vaginosis is characterized by the reduced number or absence of hydrogen peroxide-producing Lactobacillus spp., which promotes the overgrowth of anaerobic bacteria, including Gardnerella vaginalis, Mycoplasma hominis, Bacteroides spp., and Mobiluncus spp. Black race, higher-risk sexual activity, frequent vaginal douching and the substantial reduction of hydrogen peroxide-producing Lactobacillus spp. are the main predictors of bacterial vaginosis development. Clinical- and laboratory-based bacterial vaginosis diagnostic tests are widely used to screen for bacterial vaginosis but, more recently, office-based bacterial vaginosis screening tools have been developed. Although systemic treatment for bacterial vaginosis with metronidazole or clindamycin has been demonstrated to be effective in the short-term cure of bacterial vaginosis, recurrence of bacterial vaginosis within 3 months of treatment is common, and treatment for bacterial vaginosis using these strategies has not been effective in reducing the risk of preterm delivery.

New strategies for local treatment of vaginal infections

Vaginal infections are extremely prevalent, particularly among women of reproductive age. Although they do not result in high mortality rates, these infections are associated with high levels of anxiety and reduction of quality of life. In most cases, topical treatment of vaginal infections has been shown to be at least as effective as oral treatment, resulting in higher local drug concentrations, with fewer drug interactions and adverse effects. Furthermore, the emergence of microbial resistance to chemotherapeutics and the difficulties in managing infection recurrences sustain the need for more effective local treatments. However, conventional dosage forms have been associated with low retention in the vagina and discomfort. Formulation strategies such as the development of bioadhesive, thermogelling systems and microtechnological or nanotechnological approaches have been proposed to improve delivery of traditional drugs, and other treatment modalities such as new drugs, plant extracts, and probiotics are being studied. This article reviews the recent strategies studied to improve the treatment and prevention of the commonest vaginal infections-namely, vaginal bacteriosis, aerobic vaginitis, vulvovaginal candidosis, and trichomoniasis-through the intravaginal route.

BASIC study: is intravaginal boric acid non-inferior to metronidazole in symptomatic bacterial vaginosis? Study protocol for a randomized controlled trial

Background

Bacterial vaginosis is associated with increased transmission of sexually transmitted infections, preterm labor, post-surgical infections, and endometritis. Current treatment for symptomatic bacterial vaginosis includes antibiotics, such as metronidazole, which are 70–80 % effective at one month after treatment and result in high recurrence rates and secondary candida infections. Intravaginal boric acid has been used for over a hundred years to treat vaginal infections, such as bacterial vaginosis. Boric acid is inexpensive, accessible, and has shown to be an effective treatment for other infections, such as vaginal candidiasis. To date, there has been no clinical trial evaluation of boric acid effectiveness to treat bacterial vaginosis.

Methods/Design

The BASIC (Boric Acid, Alternate Solution for Intravaginal Colonization) trial is a randomized, double-blinded, multicenter study. The study will enroll a minimum of 240 women of 16–50 years of age who are symptomatic with bacterial vaginosis. Eligible participants will have Amsel and Nugent scores confirming bacterial vaginosis. Women who are pregnant or menopausal or have other active co-infections will be excluded. Consenting participants who meet exclusion and inclusion criteria will be randomly assigned to one of three treatment groups: boric acid, metronidazole, or an inert placebo. Self-administration of treatment intravaginally for 10 days will be followed by clinical assessment at 7 and 30 days (days 17 and 40, respectively) after the end of the treatment phase. Primary outcome is a non-inferiority, per-protocol comparison of the effectiveness of boric acid with that of metronidazole at day 17, as measured by the Nugent score in 16–50 year olds. Secondary outcomes include: non-inferiority, intention-to-treat comparison of effectiveness of boric acid with that of metronidazole at day 17, analysis for both per-protocol and intention-to-treat at day 40, and safety considerations, including adverse effects requiring patient discontinuation of treatment.

Discussion

This study will be the first to determine whether intravaginal boric acid is non-inferior to metronidazole in the treatment of bacterial vaginosis in symptomatic women.

Trial registration

ClinicalTrials.gov NCT00799214, registered online Nov 10, 2008.

In silico vs in vitro analysis of primer specificity for the detection of Gardnerella vaginalis, Atopobium vaginae and Lactobacillus spp

Background

Bacterial vaginosis (BV) is a common pathology of women in reproductive age that can lead to serious health complications, and is associated with shifts in the normal microflora from predominance of Lactobacillus spp. to a proliferation of other anaerobes such as G. vaginalis and A vaginae, which can be detected by PCR. The optimal PCR pathogen detection assay relies mainly on the specificity and sensitivity of the primers used.

Findings

Here we demonstrate that in silico analytical testing of primer specificity is not a synonym to in vitro analytical specificity by testing a range of published and newly designed primers with both techniques for the detection of BV-associated microorganisms.

Conclusions

By testing primer in vitro specificity with a sufficient range of bacterial strains, we were able to design primers with higher specificity and sensitivity. Also by comparing the results obtained for the newly designed primers with other previously published primers, we confirmed that in silico analysis is not sufficient to predict in vitro specificity. As such care must be taken when choosing the primers for a detection assay.

Vaginal microbiome and sexually transmitted infections: an epidemiologic perspective

Vaginal bacterial communities are thought to help prevent sexually transmitted infections. Bacterial vaginosis (BV) is a common clinical syndrome in which the protective lactic acid-producing bacteria (mainly species of the Lactobacillus genus) are supplanted by a diverse array of anaerobic bacteria. Epidemiologically, BV has been shown to be an independent risk factor for adverse outcomes including preterm birth, development of pelvic inflammatory disease, and acquisition of sexually transmitted infections. Longitudinal studies of the vaginal microbiome using molecular techniques such as 16S ribosomal DNA analysis may lead to interventions that shift the vaginal microbiota toward more protective states.

Stress, bacterial vaginosis, and the role of immune processes

Bacterial vaginosis (BV), the most common lower genital tract infection in women of reproductive age, is associated with adverse gynecologic and reproductive health outcomes. Women at highest risk for BV are young, unmarried, low income, undereducated, and African American. Behaviors such as vaginal douching, numerous sexual partners, frequent sexual intercourse, receptive oral sex, and substance use may contribute to risk, but they account for only a modest proportion of the observed race/ethnicity variance in BV. These subpopulations are also exposed to more social disadvantages or "stressors" such as poverty, poor housing, crime-infested neighborhoods, and discrimination than other groups. Growing physiologic evidence links psychosocial stress to the development of disease. Evidence supports a statistically significant, independent effect of stress on the risk and observed racial/ethnic disparity in the rate of BV. This paper reviews such evidence.

A longitudinal study of vaginal douching and bacterial vaginosis--a marginal structural modeling analysis

The etiology of bacterial vaginosis is unknown, and there are no long-term therapies for preventing this frequently recurring condition. Vaginal douching has been reported to be associated with bacterial vaginosis in observational studies. However, this association may be due to confounding by indication--that is, confounding by women douching in response to vaginal symptoms associated with bacterial vaginosis. The authors used marginal structural modeling to estimate the causal effect of douching on bacterial vaginosis risk while controlling for this confounding effect. In 1999-2002, nonpregnant women (n = 3,620) were recruited into a prospective study when they visited one of 12 public health clinics in Birmingham, Alabama, for routine care. Participants were assessed quarterly for 1 year. Bacterial vaginosis was based on a Nugent's Gram stain score of 7 or higher. Thirty-two percent of participants douched in every study interval, and 43.0% never douched. Of the 12,349 study visits, 40.2% were classified as involving bacterial vaginosis. The relative risk for regular douching as compared with no douching was 1.21 (95% confidence interval: 1.08, 1.38). These findings indicate that douching confers increased risk of disruption of vaginal flora. In the absence of a large randomized trial, these findings provide the best evidence to date for a risk of bacterial vaginosis associated with douching.

Prevalence of bacterial vaginosis among young women in low-income populations of coastal Peru

The goal of this study was to determine the prevalence of bacterial vaginosis (BV) in Peruvian women from socioeconomically deprived populations and to determine the association between BV and risk factors for sexually transmitted diseases (STDs). Women were administered an epidemiologic survey to determine sexual risk behaviour and they provided biological samples to test for BV and STDs. The prevalence of BV was high (27%) and was significantly associated with having a bacterial STD or trichomoniasis. Age, marital status, and a history of sex work, but not of sexual experience, frequency of intercourse, and unprotected intercourse, were associated with BV. As BV may be a marker for STDs, screening for STDs should be performed in individuals with BV to promote early detection and treatment of co-infecting sexually transmitted pathogens.

Findings associated with recurrence of bacterial vaginosis among adolescents attending sexually transmitted diseases clinics

STUDY OBJECTIVE

Bacterial vaginosis (BV) is a common infection and has been associated with adverse health outcomes, including preterm birth, pelvic inflammatory disease (PID), and acquisition of HIV. There are limited data on recurrent BV in adolescents. A relationship between the frequency of BV recurrence and specific risk factors might shed light on the pathophysiology of BV and lead to targeted interventions.

DESIGN

Record-based historical clinic study.

SETTING

Adolescent visits to two sexually transmitted disease (STD) clinics between 1990 and 2002.

PARTICIPANTS

254 girls who had >/= 2 episodes of BV and at least 3 clinical visits, matched on clinic attendance frequency to 254 girls with only 1 documented BV episode and 254 girls with no history of BV.

MAIN OUTCOME MEASURE

Risk factor differences between groups.

ANALYSIS

Multinomial logistic regression with robust estimator of the standard errors, accounting for repeated measures.

RESULTS

5,977 adolescent girls visited the clinics. 1509 (25%) had at least one episode of BV; of those, 303 (19.9%) had 2 or more BV episodes. Girls with a history of 1 BV episode and girls with a history of 2 or more BV episodes were more likely to be infected with Trichomonas vaginalis [OR 1.77, 95% CI: 1.17-2.67, OR 1.56, 95% CI: 1.05-2.34] and be diagnosed with PID [OR 1.50, 95% CI: 1.02-2.22, OR 2.05, 95% CI: 1.41-2.98] compared to girls with no BV history, respectively. Girls with a history of BV were also more likely to report active oral sex and lack of contraceptive use.

CONCLUSION

Adolescent girls who attend STD clinics have a high prevalence of BV. Although the association between BV and PID is not clearly causal, when one condition is diagnosed, evaluation and counseling for the other may reduce recurrence and sequelae.

Characteristics and Pregnancy Outcomes of Pregnant Women Asymptomatic for Bacterial Vaginosis

STUDY DESIGN

To determine the clinical, behavioral or demographic factors associated with asymptomatic bacterial vaginosis (BV) and to examine if women with asymptomatic BV had a higher risk of a variety of pregnancy outcomes compared to symptomatic BV positive women. For this study, 1916 pregnant women who were 12 weeks' gestation or less were enrolled. Interviewers facilitated vaginal swab collection for BV assessment, and completed the baseline questionnaire. BV was identified by Gram stain.

RESULTS

Forty percent of pregnant women screened positive for BV and a substantial proportion of BV positive pregnant women were asymptomatic (67%). Asymptomatic BV positive women reported lower stress scores (RR = 0.78, 95% CI: 0.67-0.89), slightly more prior STD's (RR = 1.03, 95% CI: 1.01-1.07), and a higher quantity of Mobiluncus (RR = 1.04 95% CI: 1.01-1.07) compared to symptomatic BV positive women. We did not find an increase in adverse pregnancy outcomes related to BV symptomatology.

CONCLUSION

Among first trimester pregnant women, only stress, STD history, and quantity of Mobiluncus were associated with symptom reports among BV positive pregnant women. We also found that women with asymptomatic BV did not have an increased risk of a variety of adverse pregnancy outcomes compared to symptomatic BV positive women.

Bacterial vaginosis in female sex workers in Chennai, India

Bacterial vaginosis (BV) causes obstetric and gynaecological complications and non-chlamydial/non-gonococcal pelvic inflammatory disease and has been shown to be associated with the risk of acquiring HIV and herpes simplex (HSV)-2 infections. This study investigated both the prevalence of BV and its association with STDs among 582 female sex workers living in Chennai, South India. Blood, vaginal and endocervical swabs were tested for HSV-2, HIV, Treponema pallidum, BV, Chlamydia trachomatis, Neisseria gonorrhoea and Trichomonas vaginalis. The vaginal swabs collected were Gram's stained and analysed for BV by Nugent's scoring criteria. Of the women studied, 45% (95% CI, 40.6-48.7) were positive, 39.5% (95% CI, 35.5-43.5) were negative and 16% (95% CI, 12.8-18.7) were intermediate for BV. Bacterial vaginosis positivity was directly related to concurrent infection with HSV-2 (RR 1.3, AR 12, P = 0.00), T vaginalis (RR 1.5, AR 10, P = 0.01) T. pallidum (RR 2.8, AR 16, P = 0.00) and HIV (RR 4.1, AR 52, P = 0.01). Future studies are needed to focus on the risk factors for BV.

Risk factors for bacterial vaginosis

OBJECTIVE

To analyse risk factors for bacterial vaginosis (BV).

STUDY DESIGN

We conducted a case-control study on risk factors for BV, in several first-level gynecological centers in Italy. Cases were women aged 18-70 years with confirmed diagnosis of BV (using test for proline iminopeptidase (PIP) activity). Control were the first patients observed in the same center without any symptom suggesting vaginal infection, and a negative PIP activity test. A total of 476 cases and 450 controls entered the study.

RESULTS

The number of sexual partners in the month before interview, but not the number of intercourses, was associated with an increased risk of BV. The risk of BV with vaginal douching or tight jeans/trousers once or more a week was 2.0 (95% CI 1.0-3.9) and 1.5 (95% CI 1.0-2.2), respectively, compared to never users.

CONCLUSION

The findings are consistent with previous data and suggest that daily habits play an important role in risk of BV.

Sexual intercourse association with asymptomatic bacterial vaginosis and Trichomonas vaginalis treatment in relationship to preterm birth

OBJECTIVE

The purpose of this study was to determine whether sexual intercourse was associated with the treatment efficacy or the incidence of preterm birth in two large randomized trials in which metronidazole treatment of bacterial vaginosis or Trichomonas vaginalis did not reduce preterm birth.

STUDY DESIGN

Secondary analysis of two multicenter, double-blind, placebo-controlled trials in which women with asymptomatic bacterial vaginosis on Gram stain or asymptomatic T vaginalis on culture were randomized at 16 to 23 weeks of gestation to metronidazole or placebo. In both studies, women took 2 g of metronidazole or placebo in the presence of a nurse (first dose) and were given a second dose to take 48 hours later. This regimen was repeated (third and fourth doses) at 24 to 29 weeks. At the time of the third dose, bacterial vaginosis and T vaginalis specimens were collected again. Patients who were randomly selected to receive metronidazole were analyzed for bacterial vaginosis and T vaginalis at 24 to 29 weeks and for preterm birth of <37 weeks of gestation, according to intercourse between first and second doses and between the second and third doses. Continuous variables were compared with the use of the Wilcoxon rank-sum test; categoric variables were compared with the use of the chi(2 ) test, Fisher exact test, or the Mantel-Haenzel test of trend.

RESULTS

Sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of bacterial vaginosis (18% vs 24%; relative risk, 0.7; 95% CI, 0.5-1.1; and 23% vs 20%; relative risk, 1.2; 95% CI, 0.9-1.6, respectively) or T vaginalis (4% vs 8%; relative risk, 0.5; 95% CI, 0.1-3.6; and 5% vs 10%; relative risk, 0.5; 95% CI, 0.2-1.1; respectively) at 24 to 29 weeks of gestation compared with no intercourse. In the T vaginalis trial, sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of preterm birth (13% vs 17%; relative risk, 0.8; 95% CI, 0.3-2.1; and 16% vs 17%; relative risk, 1.0; 95% CI, 0.6-1.6; respectively) compared with no intercourse. In the bacterial vaginosis trial, although sexual intercourse between the first and second doses did not influence the incidence of preterm birth (11% vs 12%; relative risk, 0.9; 95 % CI, 0.6-1.5), sexual intercourse between the second and third doses was associated with a reduction in the incidence of preterm birth (10% vs 16%; relative risk, 0.6; 95% CI, 0.4-0.9) compared with no intercourse.

CONCLUSION

Sexual intercourse was associated with neither the efficacy of metronidazole treatment of bacterial vaginosis or T vaginalis nor with the incidence of preterm birth. In the bacterial vaginosis study, intercourse between the second and third doses had a negative association with preterm birth.