Vaginal symptoms and bacterial vaginosis (BV): how useful is self-report? Development of a screening tool for predicting BV status

Assessment of Symptoms and Risk Factors as a Screening Tool of Bacterial Vaginosis Among Reproductive Age-Group Females in West Bengal, India

Background Bacterial vaginosis (BV) is a ubiquitous vaginal discomfort and has overlapping symptoms with other reproductive tract infections. The World Health Organization suggested a symptomatic approach for diagnosing BV with insufficient laboratory setup. However, due to symptom overlap, BV is often misled and ends up with injudicious drug application. Objective The study aims to identify the most relevant symptoms and behavioral risk factors associated with BV in tertiary healthcare settings in West Bengal, India. It also seeks to develop a scoring system based on clinical symptoms to screen for BV, especially when laboratory facilities are limited. Methodology The study is a retrospective case-control study involving 95 women of reproductive age. It employs both univariate and multivariate binary logistic regression models to identify risk factors and symptoms associated with BV. The study also compares these clinical symptoms with laboratory tests (Amsel's test) and attempts to create a scoring system for BV diagnosis. Key Findings Good menstrual hygiene and condom use were identified as key behavioral practices reducing the risk of BV. Four clinical symptoms, like malodor (P = 0.007), lower abdominal pain (P = 0.015), abnormal vaginal discharge (P = 0.071), and painful intercourse (P = 0.08), were identified as notable predictors. Based on these four symptoms, the scoring system showed a sensitivity of 88.2%, a specificity of 67.25%, and an overall accuracy of 74.7%. An additional diagnosis of vulvovaginal candidiasis (VVC) revealed that the odds of malodor (P= 0.006) and burning sensation (P= 0.011) increased significantly during co-infection.

Bacterial vaginosis: a review of approaches to treatment and prevention

Bacterial vaginosis (BV) is a common cause of vaginitis worldwide and is associated with serious reproductive health outcomes, including increased risk of preterm birth, sexually transmitted infections, and pelvic inflammatory disease. The current and only FDA-approved treatment regimens for BV are antibiotics, such as metronidazole and clindamycin. Antibiotics provide a short-term cure for bacterial vaginosis; however, fail to provide a consistent long-term cure for many women. Fifty to eighty percent of women experience a BV recurrence within a year of completing antibiotic treatment. This may be because after antibiotic treatment, beneficial strains of Lactobacillus, such as L. crispatus, do not recolonize the vagina. In the absence of an effective long-term cure, patients, providers, and researchers are exploring different approaches to treatment and prevention, resulting in a rapid evolution of perspectives on BV pathogenesis and approaches to management. Current areas of investigation for BV management include probiotics, vaginal microbiome transplantation, pH modulation, and biofilm disruption. Behavioral modifications that may help include smoking cessation, condom use and hormonal contraception. Additional strategies considered by many people include dietary modification, non-medical vaginally applied products, choice of lubricant, and treatments from medical practices outside of allopathic medicine. This review aims to provide a comprehensive and up to date outline of the landscape of ongoing and potential treatment and prevention strategies for BV.

A Syndemic Approach to Explore Factors Associated with Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common genital infection in women and is associated with an increased risk of sexually transmitted infections and HIV. This study uses a syndemic approach to evaluate factors associated with BV. Non-pregnant, HIV-negative, sexually active, cis-gender women aged 18-45 years living in Miami, Florida were recruited from Nov.2018- Jun.2021. Participants completed a sociodemographic and behavioral questionnaire along with gynecological examinations. BV was diagnosed by Amsel criteria and confirmed by a Nugent score ≥ 4. A syndemic score was calculated as the sum of factors associated with BV. The association between syndemic score and BV was assessed using logistic regression. Of 166 women included, 60.2% had BV. Race, ethnicity, education, vaginal sex, recent cannabis use, and reasons for intravaginal practices were included in the syndemic score. Higher odds of BV were found in women with a score of ≥ 3 compared to women with a score of 0/1. A higher syndemic score was associated with increased odds of having BV. Multilevel interventions to decrease BV are needed to decrease women's risk of acquiring HIV.

The vaginal microbiome: A complex milieu affecting risk of human papillomavirus persistence and cervical cancer

The purpose of this review is to describe the existing literature regarding the relationship between the vaginal microbiome, human papillomavirus persistence, and cervical cancer risk, as well as to discuss factors that mediate these relationships. Data suggest that alterations in the vaginal microbiome affect the risk of human papillomavirus infection and persistence, which has downstream effects on cervical dysplasia and cancer risk. The homeostatic Lactobillus species L. crispatus, L. gasseri, L. jensenii act to promote a healthy vaginal environment, while L. iners and pathogens causing bacterial vaginosis are associated with increased inflammation, human papillomavirus infection, cervical dysplasia, and potentially cancer. There are, however, still several large gaps in the literature, particularly related to the modifiable and non-modifiable factors that affect the vaginal microbiome and ensuing risk of pre-cancerous and cancerous lesions. Evidence currently suggests that endogenous and exogenous hormones, tobacco products, and sexual practices influence vaginal microbiome composition, but the nuances of these relationships and how changes in these factors affect dysplasia risk are yet to be delineated. Other studies examining how diet, exercise, race, socioeconomic status, and genetic factors influence the vaginal microbiome are difficult to interpret in the setting of multiple confounders. Future studies should focus on how changes in these modulatory factors might promote a healthy vaginal microbiome to prevent or treat dysplasia in the lower female genital tract.

Bacterial Vaginosis and Prospective Ultrasound Measures of Uterine Fibroid Incidence and Growth

BACKGROUND

Uterine fibroids often cause intolerable symptoms leading to invasive treatments, most commonly hysterectomy. Reproductive tract infections are hypothesized to influence uterine fibroid development, but few studies exist, especially for the highly prevalent condition bacterial vaginosis (BV). Both fibroids and BV have documented racial-ethnic disparities, with higher burden in Blacks.

METHODS

With prospective data from a community-based study (four standardized ultrasound examinations over 5 years) in young Black women, we examined baseline BV associations with fibroid incidence and growth. We computed adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incidence comparing BV and no BV (Nugent score ≥7 vs. <7) using Cox proportional hazards models among 1027 women fibroid-free at baseline. Fibroid growth associations were based on linear mixed models estimating volume change between ultrasounds indexed to 18 months. We then expressed BV association as estimated percent difference in growth per 18 months, comparing exposed and unexposed.

RESULTS

There were n = 247 incident fibroids and 1181 growth measures; average fibroid growth per 18 months was a 78% (95% CI: 69 to 87) increase in volume. BV prevalence was 51% and not associated with fibroid incidence (aHR: 1.0, 95% CI: 0.80 to 1.4) or growth (estimated % difference in growth, -3% (95% CI: -12 to 6).

CONCLUSIONS

In this first study (to our knowledge) of ultrasound-monitored fibroid development and Nugent-assessed BV, we found no evidence to support the hypothesis that BV increased risk of fibroid incidence or growth or BV's role in the high burden of fibroids in Black women.

Bacterial Vaginosis-Associated Bacteria and Uterine Fibroids: A Nested Case-Control Study

BACKGROUND

Reproductive tract infections are hypothesized to influence uterine fibroid development, yet few studies have investigated the common condition of bacterial vaginosis (BV). The literature is currently limited to data using self-report of BV.

METHODS

We conducted a nested case-control study of 200 women (100 cases and 100 controls) from a large study of 23- to 35-year-old African American women, 1310 of whom were fibroid-free and prospectively followed up for 5 years to identify incident fibroids with standardized ultrasound examinations. We used quantitative polymerase chain reaction, an objective molecular method, to assess 9 BV-associated and 4 Lactobacillus species from vaginal swab specimens. We used hierarchical logistic regression to compute odds ratios and 95% confidence intervals to examine associations between bacterial species (both individually and grouped as (1) "optimal" Lactobacillus and (2) BV-associated species) with fibroid incidence and number. We also examined vaginal imbalance (quantitatively more BV-associated bacteria than optimal Lactobacilli).

RESULTS

Contrary to our hypothesis, we found no increase in fibroid incidence or number among women with more BV-associated bacteria. High imbalance (only BV-associated bacteria, no optimal Lactobacillus bacteria) was actually inversely associated with fibroid incidence (odds ratio, 0.38; 95% confidence interval, 0.17-0.81).

CONCLUSIONS

This is the first study of ultrasound-detected incident fibroids and molecular vaginal bacterial assessment. We found no evidence that BV-associated bacteria increase the risk of fibroid incidence or number.

The influence of smoking on bacterial resistance after vaccine or antibiotic prophylaxis against recurrent urinary tract infections

INTRODUCTION

The influence of tobacco on the microbiological spectrum, resistance-sensitivity pattern and evolution in patients with recurrent urinary tract infections (RUTI) is analyzed. Evaluation of the effect of polyvalent bacterial vaccine on the prevention of RUTI and smoking status.

MATERIAL AND METHODS

Retrospective multicenter study of 855 women with RUTI receiving suppressive antibiotic treatment or bacterial vaccine between 2009 and 2013. Group A (GA): Antibiotic (n=495); Subgroups: GA1 non-smoker (n=417), GA2 smoker (n=78). Group B (GB): Vaccine (n=360); Subgroups: GB1 non-smoker (n=263), GB2 smoker (n=97).

VARIABLES

Age, pre-treatment UTI, disease-free time (DFT), microbial species, sensitivity and resistance. Follow-up at 3, 6 and 12 months with culture and SF-36 questionnaire.

RESULTS

Mean age 56.51 years (18-75), similar between groups (P=.2257). No difference in the number of pretreatment UTIs (P=.1329) or in the distribution of the bacterial spectrum (P=.7471). DFT was higher in subgroups B compared with A. Urine cultures in GA1: E. coli 62.71% with 8.10% resistance (33% quinolones; 33% cotrimoxazole; 33% quinolones + cotrimoxazole); in GA2 E. coli 61.53% with 75% resistance (16.66% quinolones; 33.33% quinolones + cotrimoxazole; 16.66% amoxicillin-clavulanate; 16.66% erythromycin + phosphomycin + clindamycin) (P=.0133). There were no differences between patients of GA treated with cotrimoxazole and nitrofurantoin (P=.8724). Urine cultures in GB1: E. coli 47.36% with 22.22% resistance (5.55% ciprofloxacin; 5.55% cotrimoxazole; 5.55% ciprofloxacin + cotrimoxazole; 5.55% amoxicillin/clavulanic acid). In GB2 E. coli 70.02% with 61.90% resistances (30.76% quinolones; 30.76% cotrimoxazole; 30.76% quinolones + cotrimoxazole; 17.69% amoxicillin-clavulanic acid) (P=.0144).

CONCLUSIONS

The development of bacterial resistance is more frequent among women with smoking habits and recurrent urinary infections. This could influence a worse response to preventive treatments, either with antibiotics or vaccines.

The Microbial Mother Meets the Independent Organ: Cultural Discourses of Reproductive Microbiomes

The human microbiome is changing the way experts and non-experts think about germs and microorganisms. This essay is a gender analysis of contemporary discourses surrounding the human reproductive microbiome, specifically the vaginal microbiota and the penile microbiota. I first historically situate the human reproductive microbiome within the germ theory of disease. Then, I draw on Heather Paxson's Foucauldian and Latourian concept of microbiopolitics to argue that microbiopolitics is not only about how humans should live with microorganisms; but it also impacts how humans and microbes live together as gendered beings. I illustrate this gendering through two figures: the microbial mother and the independent organ.

Serum 25-Hydroxyvitamin D and Risk of Self-Reported Bacterial Vaginosis in a Prospective Cohort Study of Young African American Women

BACKGROUND

Bacterial vaginosis (BV), the leading cause of vaginal discharge, is associated with multiple adverse health outcomes; however, its etiology is unknown. BV treatment is not very effective, thus prevention approaches are needed. Studies investigating the impact of vitamin D on the risk of BV have had mixed findings, including two studies reporting increased risk of recurrent BV for women with higher vitamin D.

MATERIALS AND METHODS

Participants were nonpregnant women in a prospective fibroid study of African Americans (ages 23-34 years) from the Detroit area. The exposure was seasonally adjusted annual mean serum 25-hydroxyvitamin D [25(OH)D] at enrollment. The outcome was self-reported doctor-diagnosed BV over ∼20 months between baseline and follow-up. Multivariable-adjusted binomial regression models estimated the risk of BV for a doubling of 25(OH)D and sufficient (≥20 ng/mL) versus deficient (<20 ng/mL) 25(OH)D.

RESULTS

In total, 1459 women were included. Median 25(OH)D was 15.2 ng/mL and 73% were deficient. Sixteen percent of participants reported BV diagnoses over follow-up, 78% of whom had recurrent BV. In multivariable-adjusted analyses, a doubling of 25(OH)D was associated with an increased, rather than the hypothesized decreased, risk of self-reported BV (risk ratio [RR] 1.22, 95% confidence interval 1.02-1.48). Sufficient women also had a significantly higher, rather than lower, risk of self-reported BV (RR 1.31). Results were robust to sensitivity analyses, and post hoc analyses showed no evidence of reverse causation.

CONCLUSIONS

Overall, our findings do not support vitamin D deficiency as a risk factor for BV in these young, nonpregnant African American women.

Cigarette smoking is associated with an altered vaginal tract metabolomic profile

Cigarette smoking has been associated with both the diagnosis of bacterial vaginosis (BV) and a vaginal microbiota lacking protective Lactobacillus spp. As the mechanism linking smoking with vaginal microbiota and BV is unclear, we sought to compare the vaginal metabolomes of smokers and non-smokers (17 smokers/19 non-smokers). Metabolomic profiles were determined by gas and liquid chromatography mass spectrometry in a cross-sectional study. Analysis of the 16S rRNA gene populations revealed samples clustered into three community state types (CSTs) ---- CST-I (L. crispatus-dominated), CST-III (L. iners-dominated) or CST-IV (low-Lactobacillus). We identified 607 metabolites, including 12 that differed significantly (q-value < 0.05) between smokers and non-smokers. Nicotine, and the breakdown metabolites cotinine and hydroxycotinine were substantially higher in smokers, as expected. Among women categorized to CST-IV, biogenic amines, including agmatine, cadaverine, putrescine, tryptamine and tyramine were substantially higher in smokers, while dipeptides were lower in smokers. These biogenic amines are known to affect the virulence of infective pathogens and contribute to vaginal malodor. Our data suggest that cigarette smoking is associated with differences in important vaginal metabolites, and women who smoke, and particularly women who are also depauperate for Lactobacillus spp., may have increased susceptibilities to urogenital infections and increased malodor.

Syndromic Diagnosis in Evaluation of Women with Symptoms of Vaginitis

PURPOSE OF REVIEW

This review aims to determine the effectiveness of the use of syndrome diagnosis in the evaluation of vaginitis and to make suggestions based on the review findings.

RECENT FINDINGS

Vaginal discharge as the main symptom of vaginitis is unspecific. A randomized study of symptom-based diagnosis and treatment of vaginitis in the USA favored symptoms used for treatment; however, this was only a pilot study. Hence, a population-based study is necessary to validate these findings. Most of the study that assessed treatment of vaginitis in pregnancy reported low diagnostic sensitivity and specificity for bacterial vaginosis and vaginal candidiasis and a wide range for trichomonas vaginalis reflecting ineffectiveness of syndrome-based treatment in pregnancy. A systematic review of the web for relevant literature was made, and appropriate articles were extracted and reviewed. Sensitivity, specificity, and positive values were used, where applicable to determine effectiveness. Forty-three full articles and abstracts were reviewed. Studies that validated or applied WHO algorithm for treatment of vaginitis reported high sensitivity (91.5-100%) but moderate to low specificity (0-27.5%) among women with vaginal symptoms. Studies that focused on symptoms for diagnosis of the three main etiologic agents of vaginitis reported low sensitivity and specificity, while such studies in pregnancy reported sensitivity and specificity ranging from 35.4 to 54% for TV, 11 to 100% for BV, and 0 to 56.2% for trichomonas vaginalis, bacterial vaginosis, and vaginal candidiasis, respectively. Studies that added point of care test reported higher sensitivity and specificity and positive predictive value. The use of WHO syndrome-based algorithm or its modification for treatment of vaginitis though moderately effective has the potential for overtreatment and physician error. Point of care testing and laboratory investigation are essential for productive intervention especially in pregnancy.

Bacterial vaginosis in association with spontaneous abortion and recurrent pregnancy losses

CONTEXT

Bacterial vaginosis (BV) is related to the increased risk of miscarriage, preterm labor, and postpartum endometritis.

AIMS

The aim of this study was to evaluate the association between BV and the history of spontaneous abortion and recurrent pregnancy losses. We also examined periods of gestation, including the first and second trimester miscarriages.

MATERIALS AND METHODS

The study population consisted of 200 fertile women. Sixty one (30.5%) of 200 women had the history of a spontaneous abortion in the last six months (N = 30) and at least three recurrent pregnancy losses (N = 31). BV was diagnosed either by using Papanicolaou staining, Gram staining, or by culturing with BV-associated bacteria, Gardnerella vaginalis.

RESULTS

The presence of BV was statistically associated with the history of a spontaneous abortion in the last 6 months (P < 0.05), whereas there was no significant relationship between BV and recurrent pregnancy losses (P > 0.05). These women were also evaluated in view of periods of gestation. Forty-seven (77%) of 61 women had first trimester miscarriage (≤12 weeks) and 14 (23%) of 61 women had second trimester miscarriage (>12 weeks). There was a statistically significant relationship between BV and second trimester miscarriage (P < 0.05). Positive BV findings were not associated with discharge, itching, and pain (P > 0.05).

CONCLUSION

BV may contribute to spontaneous abortion and second trimester miscarriage.

Ureaplasma parvum genotype, combined vaginal colonisation with Candida albicans, and spontaneous preterm birth in an Australian cohort of pregnant women

BACKGROUND

Detection of Ureaplasma, Mycoplasma and Candida spp. in the vagina during pregnancy has previously been associated with preterm birth (PTB). However, the prevalence of these microorganisms and the associated obstetric risks (likely to be population-specific) have not been determined in Australian women; furthermore, in the case of Ureaplasma spp., very few studies have attempted characterisation at the species level and none have examined genotype/serovar status to further refine risk assessment.

METHODS

In order to address these issues we sampled the vaginal fluid of 191 pregnant Australian women at three time points in pregnancy. Culture methods were used for detection of Ureaplasma spp. and Candida spp., and real-time PCR was used for speciation of U. parvum and U. urealyticum, non-albicans Candida spp., Mycoplasma hominis and Mycoplasma genitalium. High-resolution melt PCR was used to genotype U. parvum. Data on various lifestyle factors (including sex during pregnancy and smoking), antimicrobial use and pregnancy outcome were collected on all participants. Chi-square tests were used to assess the association of vaginal microorganisms with PTB.

RESULTS

Detection of Ureaplasma spp. was higher among spontaneous PTB cases, specifically in the presence of U. parvum [77 % preterm (95 % confidence interval (CI) 50-100 %) vs. 36 % term (CI: 29-43 %), p = 0.004], but not U. urealyticum. The association with PTB strengthened when U. parvum genotype SV6 was detected (54 % preterm (CI: 22-85 %) vs. 15 % term (CI: 10-20 %), p = 0.002); this genotype was also present in 80 % (4/5) of cases of PTB <34 weeks gestation. When present with Candida albicans in the same sample, the association with PTB remained strong for both U. parvum [46 % preterm (CI: 15-78 %) vs. 13 % term (CI: 8-18 %), p = 0.005] and U. parvum genotype SV6 [39 % preterm (CI: 8-69 %) vs. 7 % term (CI: 3-11 %), p = 0.003]. With the exception of Candida glabrata, vaginal colonisation status for all organisms was stable throughout pregnancy. Smoking significantly increased the likelihood of detection of all target organisms.

CONCLUSIONS

These data suggest that the presence of different species and serovars of Ureaplasma spp. in the vagina confers an increased risk of spontaneous PTB, findings which may be useful in risk assessment for identifying women who would benefit from antimicrobial treatment.

Bacterial vaginosis in association with spontaneous abortion and recurrent pregnancy losses

Context:

Bacterial vaginosis (BV) is related to the increased risk of miscarriage, preterm labor, and postpartum endometritis.

Aims:

The aim of this study was to evaluate the association between BV and the history of spontaneous abortion and recurrent pregnancy losses. We also examined periods of gestation, including the first and second trimester miscarriages.

Materials and Methods:

The study population consisted of 200 fertile women. Sixty one (30.5%) of 200 women had the history of a spontaneous abortion in the last six months (N = 30) and at least three recurrent pregnancy losses (N = 31). BV was diagnosed either by using Papanicolaou staining, Gram staining, or by culturing with BV-associated bacteria, Gardnerella vaginalis.

Results:

The presence of BV was statistically associated with the history of a spontaneous abortion in the last 6 months (P < 0.05), whereas there was no significant relationship between BV and recurrent pregnancy losses (P > 0.05). These women were also evaluated in view of periods of gestation. Forty-seven (77%) of 61 women had first trimester miscarriage (≤12 weeks) and 14 (23%) of 61 women had second trimester miscarriage (>12 weeks). There was a statistically significant relationship between BV and second trimester miscarriage (P < 0.05). Positive BV findings were not associated with discharge, itching, and pain (P > 0.05).

Conclusion:

BV may contribute to spontaneous abortion and second trimester miscarriage.

Prevalence of bacterial vaginosis among pregnant women attending antenatal care in Tikur Anbessa University Hospital, Addis Ababa, Ethiopia

Background

Bacterial vaginosis is one of the most common genital tract infections among reproductive age group. The prevalence of bacterial vaginosis varies from country to country even in the same country it varies among populations of interest. Different social and sexual factors can contribute to the development of bacterial vaginosis. The aim of this study was to determine the prevalence of bacterial vaginosis and to identify the possible risk factors associated among pregnant women attending antenatal care in Tikur Anbessa University Hospital, Addis Ababa, Ethiopia.

Methods

Randomly selected 57 symptomatic and 195 asymptomatic pregnant women aged between 18 and 40 years visiting obstetric and gynecological clinic from November 2011 to April 2012 screenedusing Gram stain Nugent scoring system. Statistical analysis like univariate analysis to calculate frequencies and proportions, bivariate analysis to see association of selected exposure variables with the outcome variable, and multivariate analysis to check the association of possible factors with bacterial vaginosis by adjusting potential confounding factors was calculated using SPSS (Version 16.0).

Results

The prevalence of bacterial vaginosis is 19.4% using Gram stain Nugent scoring system. In addition, prevalence of bacterial vaginosis is 31.6% and 15.9% among symptomatic and asymptomatic pregnant women respectively. A high percentage of bacterial vaginosis positive pregnant women were asymptomatic (63.3%). 36.7% bacterial vaginosis positive pregnant women reported abnormal vaginal discharge with or without unpleasant smell. Multiple lifetime sexual partner (OR: 8.6; 95% CI: 2.5, 29) and previous history of spontaneous abortion (OR: 5.9; 95% CI: 1.5, 23) had remained significantly associated with prevalence of bacterial vaginosis.

Conclusion

The prevalence of bacterial vaginosis is higher among asymptomatic pregnant women and associated with the factors previous history of multiple lifetime sexual partner and spontaneous abortion.

Association between cigarette smoking and the vaginal microbiota: a pilot study

Background

Smoking has been identified in observational studies as a risk factor for bacterial vaginosis (BV), a condition defined in part by decimation of Lactobacillus spp. The anti-estrogenic effect of smoking and trace amounts of benzo[a]pyrene diol epoxide (BPDE) may predispose women to BV. BPDE increases bacteriophage induction in Lactobacillus spp. and is found in the vaginal secretions of smokers. We compared the vaginal microbiota between smokers and non-smokers and followed microbiota changes in a smoking cessation pilot study.

Methods

In 2010–2011, 20 smokers and 20 non-smokers were recruited to a cross-sectional study (Phase A) and 9 smokers were enrolled and followed for a 12-week smoking cessation program (Phase B). Phase B included weekly behavioral counseling and nicotine patches to encourage smoking cessation. In both phases, participants self-collected mid-vaginal swabs (daily, Phase B) and completed behavioral surveys. Vaginal bacterial composition was characterized by pyrosequencing of barcoded 16S rRNA genes (V1-V3 regions). Vaginal smears were assigned Nugent Gram stain scores. Smoking status was evaluated (weekly, Phase B) using the semi-quantitative NicAlert® saliva cotinine test and carbon monoxide (CO) exhalation.

Results

In phase A, there was a significant trend for increasing saliva cotinine and CO exhalation with elevated Nugent scores (P value <0.005). Vaginal microbiota clustered into three community state types (CSTs); two dominated by Lactobacillus (L. iners, L. crispatus), and one lacking significant numbers of Lactobacillus spp. and characterized by anaerobes (termed CST-IV). Women who were observed in the low-Lactobacillus CST-IV state were 25-fold more likely to be smokers than those dominated by L. crispatus (aOR: 25.61, 95 % CI: 1.03-636.61). Four women completed Phase B. One of three who entered smoking cessation with high Nugent scores demonstrated a switch from CST-IV to a L.iners-dominated profile with a concomitant drop in Nugent scores which coincided with completion of nicotine patches. The other two women fluctuated between CST-IV and L. iners-dominated CSTs. The fourth woman had low Nugent scores with L. crispatus-dominated CSTs throughout.

Conclusion

Smokers had a lower proportion of vaginal Lactobacillus spp. compared to non-smokers. Smoking cessation should be investigated as an adjunct to reducing recurrent BV. Larger studies are needed to confirm these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-471) contains supplementary material, which is available to authorized users.

Relationship of selected bacterial vaginosis-associated bacteria to Nugent score bacterial vaginosis among urban women early in pregnancy

Among urban, primarily African American pregnant women, 74% were identified with Nugent score bacterial vaginosis (BV). All BV-associated bacteria were more prevalent among women with Nugent score BV. Bacterial vaginosis-associated bacteria 3 (BVAB3) had the highest positive predictive value, whereas Gardnerella vaginalis and Atopobium spp. had the highest sensitivity. Atopobium spp. levels had the most significant area under the curve.

Tobacco use increases susceptibility to bacterial infection

Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.