Comparison of Gram-stained smears prepared from blind vaginal swabs with those obtained at speculum examination for the assessment of vaginal flora

Bacterial Vaginosis: A Comprehensive Narrative on the Etiology, Clinical Features, and Management Approach

Due to the intricate balance of the vaginal microbiota's ecology, bacterial vaginosis is documented in one-third of females globally at various times of their lives. It is a typical reason for unusual vaginal discharge and is linked to various health problems. Gardnerella vaginalis is one of the anaerobic microorganisms linked to bacterial vaginosis. bacterial vaginosis is diagnosed by Amsel's criteria as well as comparisons among Amsel's criteria, Nugent's criteria, and Hay/Ison's criteria. To scan and assess the degree of dysbiosis within the vaginal microbiome, researchers have upped their game by combining cutting-edge molecular methods, with a focus on how specific microbial populations fluctuate in comparison to a healthy condition. A clue cell can be detected on a simple wet mount of vaginal secretions. Despite receiving regular antibiotic therapy, a substantial risk of treatment failure and bacterial vaginosis recurrence persists. Researchers have revealed positive treatment effects and reduced the infection of the female reproductive system with harmful bacteria.

Genome-Wide Mutagenesis Identifies Factors Involved in Enterococcus faecalis Vaginal Adherence and Persistence

Enterococcus faecalis is a Gram-positive commensal bacterium native to the gastrointestinal tract and an opportunistic pathogen of increasing clinical concern. E. faecalis also colonizes the female reproductive tract, and reports suggest vaginal colonization increases following antibiotic treatment or in patients with aerobic vaginitis. Currently, little is known about specific factors that promote E. faecalis vaginal colonization and subsequent infection. We modified an established mouse vaginal colonization model to explore E. faecalis vaginal carriage and demonstrate that both vancomycin-resistant and -sensitive strains colonize the murine vaginal tract. Following vaginal colonization, we observed E. faecalis in vaginal, cervical, and uterine tissue. A mutant lacking endocarditis- and biofilm-associated pili (Ebp) exhibited a decreased ability to associate with human vaginal and cervical cells in vitro but did not contribute to colonization in vivo Thus, we screened a low-complexity transposon (Tn) mutant library to identify novel genes important for E. faecalis colonization and persistence in the vaginal tract. This screen revealed 383 mutants that were underrepresented during vaginal colonization at 1, 5, and 8 days postinoculation compared to growth in culture medium. We confirmed that mutants deficient in ethanolamine catabolism or in the type VII secretion system were attenuated in persisting during vaginal colonization. These results reveal the complex nature of vaginal colonization and suggest that multiple factors contribute to E. faecalis persistence in the reproductive tract.

Evaluation of patient- versus provider-collected vaginal swabs for microbiome analysis during pregnancy

Objective

We aimed to evaluate if patient- and provider-collected vaginal swabs in pregnant women reflect similar bacterial community characteristics. Pregnant patients performed a self-collected vaginal swab, then underwent a provider-collected swab via speculum exam. DNA pyrosequencing of the 16S rRNA gene V1V3 and V3V5 variable regions was performed. Relative abundance of taxa, alpha diversity, and beta diversity of patient- and provider-collected swabs were compared.

Results

Ninety-four vaginal swabs from 47 women were analyzed. On non-metric multi-dimensional scaling plots, paired patient- and provider-collected swabs clustered closely. The median Pearson correlation coefficient was 0.993 (interquartile range 0.951–0.999) for V1V3 and 0.987 (interquartile range 0.902–0.999) for V3V5. Among paired V1V3 and V3V5 sequences, 83.0% and 73.9% showed strong Pearson correlation (> 0.9), respectively, between patient- and provider-collected swabs; V1V3 and V3V5 sequences with weaker Pearson correlation (< 0.9) had correlation coefficients 0.57–0.89 and 0.49–0.89, respectively. No taxa were preferentially detected by sampling method, with relative abundance of taxa highly conserved. No significant difference in Shannon diversity for V1V3 (p = 0.22) and V3V5 (p = 0.11) sequences among paired samples was seen. We demonstrate that bacterial communities defined from patient- and provider-collected vaginal swabs in pregnant women are similar, validating utilization of patient-collected swabs for vaginal bacterial microbiome sampling during pregnancy.

A Comparison of the Use of Papanicolaou-stained Cervical Cytological Smears with Gram-stained Vaginal Smears for the Diagnosis of Bacterial Vaginosis in Early Pregnancy

Our objective is to compare the efficacy of using Papanicolaou (PAP)-stained cervical cytology smears with a standardized method of interpreting Gram-stained vaginal smears for the diagnosis of bacterial vaginosis (BV) in pregnancy.

High vaginal smears were Gram-stained and examined by a single observer to characterize 3 grades of vaginal flora and diagnose BV. Cervical smears were PAP-stained and examined for characteristic patterns of vaginal flora including evidence of BV by either a number of cytotechnicians or a single cytopathologist. The results of the 2 methods were compared. Seven hundred and forty-seven women attending an antenatal clinic in a district general hospital who consented to have a smear of vaginal secretions and cervical cytology in early pregnancy. The main outcome measure is the diagnosis of BV by different methods in a pregnant population.

Compared with the Gram-stain method for the diagnosis of BV, there was good agreement between PAP-stain interpretation by a single observer but the agreement was not as good with PAP-stain interpretation by multiple cytotechnicians. When the grades were consolidated to normal (grade I) and abnormal flora (grades II and III), compared to Gram-stained smears, PAP cytology undertaken by several cytotechnicians had a sensitivity of 80.7% and a specificity of 90.7%. The sensitivity and specificity increased to 87% and 97%, respectively, when the PAP-stained smears were read by a single cytopathologist. Using kappa scores, only those readings made by a single cytopathologist were reliable.

The setting in a cytopathology laboratory comprises multiple cytotechnicians, so that PAP-stain analysis of vaginal smears for the diagnosis of BV is likely to provide results which are less reliable than those obtained by Gram staining. The latter should be the first choice and every effort should be made to set up this service.

Daily temporal dynamics of vaginal microbiota before, during and after episodes of bacterial vaginosis

BACKGROUND

Bacterial vaginosis (BV) is a common gynecologic diagnosis characterized by dysbiosis of the vaginal microbiota. It is often accompanied by vaginal symptoms such as odor and discharge, but can be asymptomatic. Despite over 50 years of research, the etiology of BV is not well understood, which is a major impediment to treatment and prevention of BV.

RESULTS

Here we report on the temporal dynamics of 25 vaginal communities over a 10 week period using samples collected daily from women who were diagnosed with symptomatic BV (15 women), asymptomatic BV (6 women), and women who did not have BV (4 women).

CONCLUSION

This unique resource of samples and data will contribute to a better understanding of the role that the vaginal microbes have in the natural history of BV and lead to improved diagnosis and treatment.

Six years observation after successful treatment of bacterial vaginosis

OBJECTIVE

The cure rate after treatment of bacterial vaginosis (BV) differs in various investigations, but most studies report a cure rate of 70% after 1 month.

METHODS

A long-term observation study after successful treatment of BV has been undertaken. The original study was a treatment study of BV and included 50 patients.

RESULTS

We were able to identify 44 of the original 50 patients. The mean follow-up time was 6.9 years (range 4.7-9 years). During this time, 21 women (48%) had been free of BV while 23 women had had relapses. There was no difference in the use of broad-spectrum antibiotics, episodes of candida vaginitis, bleeding disturbances, family planning method, development of cervical intraepithelial neoplasia (CIN), or gynecological operations between women with and without relapses. The women with relapses had had a new sexual contact more often during the observation period than women without relapses. There was no difference in hydrogen peroxide production of the lactobacilli among women with or without relapses, and survival analysis shows that most relapses occur during the first year after treatment.

CONCLUSIONS

If patients are successfully treated, half of the patients will stay cured indicating that treatment is of benefit. Most relapses occur during the first year. Our results indicate that the etiology of BV might have something to do with new sexual contacts.

Vaginal microbiome: rethinking health and disease

Vaginal microbiota form a mutually beneficial relationship with their host and have a major impact on health and disease. In recent years our understanding of vaginal bacterial community composition and structure has significantly broadened as a result of investigators using cultivation-independent methods based on the analysis of 16S ribosomal RNA (rRNA) gene sequences. In asymptomatic, otherwise healthy women, several kinds of vaginal microbiota exist, the majority often dominated by species of Lactobacillus, while others are composed of a diverse array of anaerobic microorganisms. Bacterial vaginosis is the most common vaginal condition and is vaguely characterized as the disruption of the equilibrium of the normal vaginal microbiota. A better understanding of normal and healthy vaginal ecosystems that is based on their true function and not simply on their composition would help better define health and further improve disease diagnostics as well as the development of more personalized regimens to promote health and treat diseases.

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.

The laboratory diagnosis of bacterial vaginosis

Bacterial vaginosis (BV) is an extremely common health problem for women. In addition to the troublesome symptoms often associated with a disruption in the balance of vaginal flora, BV is associated with adverse gynecological and pregnancy outcomes. Although not technically a sexually transmitted infection, BV is a sexually associated condition. Diagnostic tests include real-time clinical/microbiological diagnosis, and the current gold standard, the standardized evaluation of morphotypes on Gram stain analysis. The inappropriate use of vaginal culture can be misleading. Future developments into molecular-based diagnostics will be important to further understand this complex endogenous flora disruption.

The short-term variability of bacterial vaginosis diagnosed by Nugent Gram stain criteria among sexually active women in Rakai, Uganda

BACKGROUND

Studies evaluating clinical and behavioral factors related to short-term fluctuations in vaginal microbiota are limited. We sought to describe changes in vaginal microbiota evaluated by Gram stain and assess factors associated with progression to and resolution of bacterial vaginosis (BV) at weekly intervals.

METHODS

A cohort of 255 sexually experienced, postmenarcheal women provided self-collected vaginal swabs to assess vaginal microbiota by Nugent score criteria at weekly visits for up to 2 years contributing 16,757 sequential observations. Absolute differences in Nugent scores (0-10) and transition probabilities of vaginal microbiota states classified by Nugent score into normal (0-3), intermediate (4-6), and BV (7-10) between visits were estimated. Allowing each woman to serve as her own control, weekly time-varying factors associated with progression from normal microbiota to BV and resolution of BV to normal microbiota were estimated using conditional logistic regression.

RESULTS

The distribution of absolute difference in Nugent scores was fairly symmetric with a mode of 0 (no change) and a standard deviation of 2.64. Transition probabilities showed weekly persistence, was highest for normal (76.1%) and BV (73.6%) states; whereas, intermediate states had similar probabilities of progression (36.6%), resolution (36.0%), and persistence (27.4%). Weekly fluctuation between normal and BV states was associated with menstrual cycle phase, recency of sex, treatment for vaginal symptoms, pregnancy, and prior Nugent score.

CONCLUSIONS

Weekly changes in vaginal microbiota were common in this population. Clinical and behavioral characteristics were associated with vaginal microbiota transitioning, which may be used to inform future studies and clinical management of BV.

Rapid fluctuation of the vaginal microbiota measured by Gram stain analysis

BACKGROUND

The aetiology of bacterial vaginosis (BV) remains unknown.

OBJECTIVE

To describe longitudinal changes in vaginal microbiota.

METHODS

Thirty-nine women (mean age 36.8 years; 22 (56.4%) African-American) self-collected vaginal specimens twice weekly for 16 weeks as part of a vaginal douching cessation study. In an analysis where each woman serves as her own control, conditional logistic regression was used to evaluate daily, time-varying factors associated with a woman's incident BV episode(s) as compared with her persistently BV-negative sample(s). BV was defined by a Nugent's Gram stain score >or=7.

RESULTS

46.2% of participants had BV in the first 4 weeks of observation. Rapid fluctuation of vaginal microbiota was observed in 226 transitions to BV or spontaneous remission. Duration of BV was often short: 51% of the episodes lasted for only one sample interval (3 days). Among women who had at least one BV episode, the median number of episodes per woman was 8.7 (SD 7.4, range 1-22). Lubricant use 1 day before specimen collection (adjusted OR (aOR)=11.75, 95% CI 1.96 to 70.27) and rectal sex 2 days before (aOR=4.48, 95% CI 2.79 to 7.17) were associated with BV onset.

CONCLUSION

Rapid fluctuation of the vaginal microbiota was seen. Longitudinal studies with long intervals between sampling are likely to miss episodes of BV. Recent report of lubricant use and rectal sex were associated with incident BV.

Two Methods of Self-Sampling Compared to Clinician Sampling to Detect Reproductive Tract Infections in Gugulethu, South Africa

OBJECTIVES

To assess the validity, feasibility, and acceptability of 2 methods of self-sampling compared to clinician sampling during a speculum examination.

GOAL

To improve screening for reproductive tract infections (RTIs) in resource-poor settings.

STUDY DESIGN

In a public clinic in Cape Town, 450 women underwent a speculum examination and were randomized to self-sample with either a tampon or vaginal swabs. All specimens were tested for the same pathogens using the same diagnostic tests.

RESULTS

Self-sampling resulted in satisfactory validity for N gonorrhoeae, C trachomatis, bacterial vaginosis, and Candida species (tampons and swabs) and high-risk human papillomavirus (swabs only) when tested with molecular tests or microscopy, but not for T vaginalis by culture. Self-sampling was feasible and acceptable, but some women preferred speculum examinations, which allow the clinician to view the vagina and cervix.

CONCLUSIONS

Although self-sampling should not replace speculum examinations in all circumstances, it should be explored further as an RTI screening strategy.

Community-based interventions for improving perinatal and neonatal health outcomes in developing countries: a review of the evidence

BACKGROUND

Infant and under-5 childhood mortality rates in developing countries have declined significantly in the past 2 to 3 decades. However, 2 critical indicators, maternal and newborn mortality, have hardly changed. World leaders at the United Nations Millennium Summit in September 2000 agreed on a critical goal to reduce deaths of children <5 years by two thirds, but this may be unattainable without halving newborn deaths, which now comprise 40% of all under-5 deaths. Greater emphasis on wide-scale implementation of proven, cost-effective measures is required to save women's and newborns' lives. Approximately 99% of neonatal deaths take place in developing countries, mostly in homes and communities. A comprehensive review of the evidence base for impact of interventions on neonatal health and survival in developing-country communities has not been reported.

OBJECTIVE

This review of community-based antenatal, intrapartum, and postnatal intervention trials in developing countries aimed to identify (1) key behaviors and interventions for which the weight of evidence is sufficient to recommend their inclusion in community-based neonatal care programs and (2) key gaps in knowledge and priority areas for future research and program learning.

METHODS

Available published and unpublished data on the impact of community-based strategies and interventions on perinatal and neonatal health status outcomes were reviewed. Evidence was summarized systematically and categorized into 4 levels of evidence based on study size, location, design, and reported impact, particularly on perinatal or neonatal mortality. The evidence was placed in the context of biological plausibility of the intervention; evidence from relevant developed-country studies; health care program experience in implementation; and recommendations from the World Health Organization and other leading agencies.

RESULTS

A paucity of community-based data was found from developing-country studies on health status impact for many interventions currently being considered for inclusion in neonatal health programs. However, review of the evidence and consideration of the broader context of knowledge, experience, and recommendations regarding these interventions enabled us to categorize them according to the strength of the evidence base and confidence regarding their inclusion now in programs. This article identifies a package of priority interventions to include in programs and formulates research priorities for advancing the state of the art in neonatal health care.

CONCLUSIONS

This review emphasizes some new findings while recommending an integrated approach to safe motherhood and newborn health. The results of this study provide a foundation for policies and programs related to maternal and newborn health and emphasizes the importance of health systems research and evaluation of interventions. The review offers compelling support for using research to identify the most effective measures to save newborn lives. It also may facilitate dialogue with policy makers about the importance of investing in neonatal health.

Effect of early oral clindamycin on late miscarriage and preterm delivery in asymptomatic women with abnormal vaginal flora and bacterial vaginosis: a randomised controlled trial

BACKGROUND

Abnormal vaginal flora and bacterial vaginosis are associated with amplified risks of late miscarriage and spontaneous preterm delivery. We aimed to establish whether antibiotic treatment early in the second trimester might reduce these risks in a general obstetric population.

METHODS

We screened 6120 pregnant women attending hospital for their first antenatal visit--who were at 12-22 weeks' gestation (mean 15.6 weeks)--for bacterial vaginosis or abnormal vaginal flora. We used gram-stained slides of vaginal smears to diagnose abnormal vaginal flora or bacterial vaginosis, in accordance with Nugent's criteria. We randomly allocated 494 women with one of these signs to receive either clindamycin 300 mg or placebo orally twice daily for 5 days. Primary endpoints were spontaneous preterm delivery (birth > or =24 but <37 weeks) and late miscarriage (pregnancy loss > or =13 but <24 weeks). Analysis was intention to treat.

FINDINGS

Nine women were lost to follow-up or had elective termination. Thus, we analysed 485 women with complete outcome data. Women receiving clindamycin had significantly fewer miscarriages or preterm deliveries (13/244) than did those in the placebo group (38/241; percentage difference 10.4%, 95% CI 5.0-15.8, p=0.0003). Clindamycin also reduced adverse outcomes across the range of abnormal Nugent scores, with maximum effect in women with the highest Nugent score of 10.

INTERPRETATION

Treatment of asymptomatic abnormal vaginal flora and bacterial vaginosis with oral clindamycin early in the second trimester significantly reduces the rate of late miscarriage and spontaneous preterm birth in a general obstetric population.

Association between bacterial vaginosis or chlamydial infection and miscarriage before 16 weeks' gestation: prospective community based cohort study

OBJECTIVES

To assess whether bacterial vaginosis or chlamydial infection before 10 weeks' gestation is associated with miscarriage before 16 weeks.

DESIGN

Prospective cohort study.

SETTING

32 general practices and five family planning clinics in south London.

PARTICIPANTS

1216 pregnant women, mean age 31, presenting before 10 weeks' gestation.

MAIN OUTCOME MEASURE

Prevalence of miscarriage before 16 weeks' gestation.

RESULTS

121 of 1214 women (10.0%, 95% confidence interval 8.3% to 11.7%) miscarried before 16 weeks. 174 of 1201 women (14.5%, 12.5% to 16.5%) had bacterial vaginosis. Compared with women who were negative for bacterial vaginosis those who were positive had a relative risk of miscarriage before 16 weeks' gestation of 1.2 (0.7 to 1.9). Bacterial vaginosis was, however, associated with miscarriage in the second trimester at 13-15 weeks (3.5, 1.2 to 10.3). Only 29 women (2.4%, 1.5% to 3.3%) had chlamydial infection, of whom one miscarried (0.32, 0.04 to 2.30).

CONCLUSION

Bacterial vaginosis is not strongly predictive of early miscarriage but may be a predictor after 13 weeks' gestation. The prevalence of Chlamydia was too low to assess the risk, but it is unlikely to be a major risk factor in pregnant women.

The future of bacterial vaginosis-related research

Various ways and criteria are used to diagnose BV. Guidelines should be redrawn and they should embody greater uniformity. The etiology of BV remains enigmatic. However, various observations suggest that host factors, possibly hormonal, cause an imbalance in the vaginal microflora. Exogenous factors, such as semen and antibiotics, may then help to bring about a more prolonged change. This forms a working hypothesis for further exploration. The role of the lactobacillus phage in the development of BV also needs to be determined. Various conditions may occur as a consequence of BV in non-pregnant and pregnant women and BV may also affect men. A subjective assessment of the extent to which these associations occur or are likely to be shown to occur by further investigations is presented in Table 1. The ability to cure acute BV needs to be improved as does the treatment of chronic BV, for which vaginal recolonization with exogenous lactobacilli is an approach to be evaluated further.