Vaginal flora alterations and clinical symptoms in low-risk pregnant women

Vulvovaginitis in pregnant women

• The balanced vaginal microbiome is the main factor defending the vaginal environment against infections. Lactobacilli play a key role in this regard, maintaining the vaginal pH within the normal range (3.8 to 4.5). •Hormonal and immune adaptations resulting from pregnancy influence changes in the vaginal microbiome during pregnancy. •An altered vaginal microbiome predisposes to human immunodeficiency virus (HIV) infection. •Bacterial vaginosis is the main clinical expression of an imbalanced vaginal microbiome. •Vulvovaginal candidiasis depends more on the host's conditions than on the etiological agent. •Trichomonas vaginalis is a protozoan transmitted during sexual intercourse. •The use of probiotics is not approved for use in pregnant women.

Microbial Diversity and Pathogenic Properties of Microbiota Associated with Aerobic Vaginitis in Women with Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is a major reproductive problem that affects approximately 5% of couples. The objective of this study was to assess vaginal flora dysbiosis in women suffering from unexplained RPL and to investigate the pathogenic properties of the microbiota associated with aerobic vaginitis (AV). The study included one hundred fifteen women, 65 with RPL and 50 controls. The diversity of vaginal microbiota isolated was evaluated by molecular sequencing. Then, pathogenic factors, such as acid-resistance, antibiotics susceptibility, and biofilm formation were evaluated. The prevalence of AV was five-fold higher in the RPL group than in the controls (64.6% vs. 12.0%). The most prevalent isolates in the case group were Enterococcus spp. (52%) and Staphylococcus spp. (26%). All bacterial strains tolerate low pH. The prevalence of multidrug resistance (MDR) among all bacteria was 47.7%. Of all strains, 91.0% were biofilm producers. The presence of MDR was found to be related to biofilm formation. The results provide evidence supporting an increased presence of dysbiosis of the vaginal flora, especially AV, in women with RPL in Tunisia. The viability of the AV-associated bacteria and their persistence in the genitals may be due to their ability to resist low pH and to produce a biofilm.

Abnormal vaginal flora correlates with pregnancy outcomes: A retrospective study from 737 pregnant women

OBJECTIVE

Abnormal vaginal flora (AVF) is a common cause of vulvovaginal symptoms in women. This study aims to investigate the prevalence of AVF in pregnant women and assess associations between diverse AVF subtypes and pregnancy outcomes.

METHODS

This study retrospectively collected clinical data of pregnant women who had vaginal flora tests (VFT) between January 2015 and December 2018 in the First Affiliated Hospital of Xi'an Jiaotong University. AVF were defined into different subtypes according to the results of VFT, including bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), aerobic bacteria (AV), cytolytic vaginosis (CV), and trichomoniasis. Pregnancy outcomes included gestational age at delivery, preterm birth (PTB), premature rupture of membranes (PROM), and infant birth weight. Student's t-test and Fisher's exact test was used for analyses using SPSS 22.0. P < 0.05 was considered as statistical significance.

RESULTS

A total of 737 pregnant women were included in this study. Pregnant women in AVF group suffered more PROM than women in normal vaginal flora (NVF) group (18.8% [33/176] vs 10.6% [32/302], P = 0.012); pregnant women with BV (31.3% [5/16] vs 10.6% [32/302], P = 0.018) and mixed vaginitis (55.6% [5/9] vs 10.6% [32/302], P = 0.001) had higher PROM rates than women in the NVF group. In addition, pregnant women in NVF and AVF groups had similar PTB rates (5.0% [15/302] vs 3.5% [32/302], P = 0.38).

CONCLUSIONS

AVF, including BV and Mixed vaginitis, augments PROM risk in pregnant women, demonstrating the need for vaginal flora examination during pregnancy.

Mixed Vaginitis in the Third Trimester of Pregnancy Is Associated With Adverse Pregnancy Outcomes: A Cross-Sectional Study

Mixed vaginitis is a complex vaginal dysbiosis that differs from single vaginitis. Vaginitis in the third trimester may lead to adverse maternal and neonatal outcomes. The clinical characteristics, microbiological characteristics, and adverse pregnancy outcomes of mixed vaginitis in late pregnancy are worth studying. Therefore, this study investigated the clinical and microbiological characteristics of vaginitis and adverse pregnancy outcomes of patients with mixed vaginitis. We studied 1,674 women in late pregnancy who attended the Tianjin Medical University General Hospital from November, 2019 to October, 2021. We administered standardized questionnaires, performed vaginal examination and sampling plus microscope examinations, and assessed follow-up pregnancy outcomes. We cultured the vaginal discharge of the patients with mixed vaginitis to isolate pathogens and performed antimicrobial susceptibility tests of the isolated pathogens. For the patients with peripartum infection, we collected a sample to isolate pathogens. Among the 1,674 women, 66 (3.9%) had mixed vaginitis. The independent risk factor for mixed vaginitis in late pregnancy was a history of vaginitis during early and middle pregnancy (OR = 5.637, 95% CI: 3.314–9.580). The signs of vaginal erythema (63.6% vs. 42.0%), yellow discharge (81.8% vs. 59.6%), and malodor (31.8% vs. 18.8%) (P <0.05) were significantly higher in patients with mixed vaginitis than in patients with single vaginitis. Bacterial isolates of the vaginal secretions of patients with mixed bacterial vaginitis were mainly the pathogens of aerobic vaginitis and bacterial vaginosis, such as Gardnerella vaginalis, Streptococcus anginosus, and Staphylococcus epidermidis. Pathogen isolation of the vaginal secretions of patients with mixed fungus and bacteria vaginitis mainly included Candida albicans, followed by S. anginosus, Enterococcus faecalis, Staphylococcus hemolyticus, Staphylococcus aureus, Streptococcus agalactiae and Staphylococcus simulans. Women with mixed vaginitis had an increased incidence and risk of peripartum infections (6.1% vs. 1.4%, P <0.05; OR = 3.985, 95% CI:1.214–13.079). Escherichia coli is the main pathogen that causes peripartum infection. Mixed vaginitis in late pregnancy is characterized by a severe and complex phenotype, complex vaginal dysbiosis, and a long course of vaginal dysbiosis. This can lead to an increased incidence and risk of peripartum infection. Therefore, more attention should be paid to patients with mixed vaginitis in the third trimester of pregnancy.

Recent Advances in Presentation, Diagnosis and Treatment for Mixed Vaginitis

Mixed vaginitis is the simultaneous presence of at least two types of vaginitis, contributing to an abnormal vaginal milieu and leading to vaginal symptoms and signs. However, associations between symptoms and the type of mixed vaginitis have not been clearly elucidated, and research on mixed vaginitis is still in the preliminary stage. Therefore, the pathogenic mechanism of mixed vaginitis remains understudied. Mixed vaginitis generally involves the formation of mixed biofilms. The study of polymicrobial interactions and mixed biofilms will provide a new idea for the understanding of mixed vaginitis. Moreover, this review summarizes some effective management and laboratory diagnosis of mixed vaginitis to avoid inappropriate therapy, recurrence, and reinfection. It is of high clinical importance to obtain relevant clinical data to improve clinical knowledge about mixed vaginitis.

Prevalence of vulvovaginal candidiasis in Brazil: a systematic review

Vulvovaginal candidiasis (CVV) is a condition whose signs and symptoms are related to inflammation caused by Candida spp infection. It is the second leading cause of vaginitis in the world, representing a public health problem. The present systematic review comes with the proposal of analyze and identify the available evidence on CVV prevalence in Brazil, pointing out its variability by regions. For this, a systematic literature review was carried out with meta-analysis of cross-sectional and cohort studies, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guide recommendations, and was registered in the International Prospective Register of Systematic Reviews (PROSPERO 2020 CRD42020181695). The databases used for survey were LILACS, Scielo, Scopus, PUBMED, Web of Science and CINAHL. Fifteen studies were selected to estimate CVV prevalence in the Brazilian territory. South and Southeast regions have higher prevalences than the North and Northeast regions, no data were found for the Midwest region. The estimated prevalence for Brazil is 18%, however, it is suggested that this number is higher due to underreporting and the presence of asymptomatic cases. Therefore, new epidemiological studies are recommended throughout Brazil, to elucidate the profile of this disease in the country, in addition to assisting in the elaboration of an appropriate prevention plan by state.

LAY ABSTRACT

Data found in the literature regarding the epidemiological profile of VVC in Brazil are obsolete and incomplete, so the present systematic review has the proposal to analyze and identify the evidence on VVC prevalence in Brazil. The estimated prevalence is 18%, however, this number can be higher.

Vaginal microbiota evaluation and prevalence of key pathogens in ecuadorian women: an epidemiologic analysis

Vaginal infection is a gynecological problem in women of reproductive age with multiple health outcomes. The most common forms of infection include bacterial vaginosis (BV), vulvovaginal candidiasis (VC), and aerobic vaginitis (AV). Our main goals were to evaluate different types of vaginal infections in Ecuadorian women in a large urban area (Quito) and to characterize the vaginal microbiota colonization by opportunistic species. We collected vaginal swabs and epidemiological surveys from 414 women from June 2016 to July of 2017. We analyzed vaginal samples for the presence of any vaginal infection. The microbiological examination was done through Gram-stain, wet mount smears, and polymerase chain reaction (PCR) assays using primers for target genes, such as 16S rRNA (Atopobium vaginae, Mobiluncus mulieris, and Gardnerella species), ddl (Enterococcus faecalis), adk (Escherichia coli) and KER1 (Candida albicans) genes. Most women showed a healthy vaginal microbiota (66.7%). Nearly one-tenth (10.4%) of the participants had intermediate microbiota, and the remaining women (22.9%) had a single vaginal infection (BV, AV, or VC) or coinfections. From the 95 participants that had an infection, AV was the main diagnosed vaginal infection (51.6%), followed by BV (24.2%) and finally VC (7.4%). The remaining women (16.8%) showed coinfections, being BV and AV the most common coinfection. Using univariable logistic regression analyses we found an increased odds of healthy microbiota in women with a sexual partner (P = 0.02, OR = 1.64). Also, women in a free union relationship (P = 0.000, OR = 16.65) had an increased odds of having coinfections. On the other hand, the use of birth control (condom OR = 0.388 or other contraceptive method OR = 0.363) was associated with significantly lower odds of intermediate microbiota (P ≤ 0.05). We found no statistically significant differences between women with infection and a particular group age. Using multivariate logistic regression analyses we initially found an increased odds of having BV in women with M. mulieris (P = 0.020, OR = 4.98) and Gardnerella species (P = 0.010, OR = 4.16). Women with E. coli showed an increased odds of having AV (P = 0.009, OR = 2.81). The presence of C. albicans in women showed an increased odds of having VC (P = 0.007, OR = 17.94). Finally, women with M. mulieris showed a reverse odds of having healthy microbiota (P = 0.008, OR = 0.06). We found no statistically significant differences between women with symptomatic and asymptomatic infections or the presence of Enterococcus faecalis. We found using logistic regression analyses that M. mulieris was the most prevalent opportunistic pathogen among women with vaginal infection. Further studies should evaluate the possibility to use M. mulieris as a potential key predictor for vaginal infections.

Aerobic vaginitis - An underdiagnosed cause of vaginal discharge - Narrative review

The concept of vaginal dysbiosis was for long considered synonymous with bacterial vaginosis (BV), which is characterized by a homogenous non-inflammatory vaginal discharge. The inflammatory variant of vaginal dysbiosis, called aerobic vaginitis (AV), has remained unknown to a large part of the global dermatology and venereology community, gynaecologists and reproductive tract infection specialists with consequential under diagnosis. AV significantly differs from BV, in clinical presentation, diagnostic criteria and management. The deleterious impact of untreated AV on pregnancy merits discussion. Understanding AV is also crucial for better comprehension of desquamative inflammatory vaginitis (DIV), the most severe form of the same entity. We review the condition's epidemiology, risk factors and suspected aetiology, symptoms and signs, and the latest evidence-backed approach to diagnosis and treatment. The ideal diagnostic approach and treatment for AV/DIV are yet to be established. The currently recommended diagnostic approach for AV/DIV merits an overhaul by incorporating changes to render it feasible for resource-constraint countries. The diagnostic criteria lack a uniform applicability in different physiological groups of women and cannot be used in postpartum or postmenopausal states at the same cut-off levels. Similarly, treatment guidelines merit a relook, and customization, given the equivocality of options suggested by different investigators.

Vaginal Microbiota Evaluation and Lactobacilli Quantification by qPCR in Pregnant and Non-pregnant Women: A Pilot Study

Pregnancy outcomes and women's health are directly affected by vaginal microbiota. This microbiota consists of a dynamic ecosystem of various microbes in different ratios, which in healthy conditions protect the vaginal epithelium from infections. However, cases of vaginal infection are regularly diagnosed in women of reproductive age, contributing to more severe outcomes. Therefore, our main goal was to determine the prevalence of bacterial vaginosis (BV), aerobic vaginitis (AV), and vulvovaginal candidiasis (VVC) among Ecuadorian pregnant and non-pregnant women. A cross-sectional study was conducted among 217 women between 13 and 40 years old seeking primary healthcare in Carlos Andrade Marin Hospital (HCAM), Gynecological-Obstetric Hospital Isidro Ayora (HGOIA) and Center for Teaching Health Cipriana Dueñas during October 2018 to February 2019. The classical characterization of the vaginal microbiota was performed through microscopy by the Nugent criteria to evaluate the presence of BV, healthy and intermediate microbiota, by the criteria of Donders to determine the presence of AV and by the Marot-Leblond criteria to diagnose VVC. DNA extraction from vaginal samples and Polymerase Chain Reaction (PCR) analysis was performed to characterize the presence of Gardnerella spp., Mobiluncus mulieris, Escherichia coli, Enterococcus spp., and Lactobacillus spp. Finally, quantification of the lactobacilli was performed by quantitative real-time PCR (qPCR) for samples from women with normal vaginal microbiota and women with AV. Our results showed 52% of women with healthy microbiota, 7% with intermediate microbiota, and 41% with vaginal dysbiosis, comprising 27% with AV, 8% with BV and 4% with VVC and 2% with co-infections or co-dysbiosis. Additionally, a higher amount of lactobacilli were found in pregnant women when compared to non-pregnant women, while AV cases were characterized by a significant drop of Lactobacillus spp., more precisely, between 1E3 and 1E5 colony forming units (CFU)/ml. Finally, women with normal vaginal microbiota showed an average load of lactobacilli between 1E6 and 1E7 CFU/ml. This pilot study showed no statistically significant differences between pregnant and non-pregnant women, pointing to the possibility to use lactobacilli quantification for the prevention of future vaginal infections.

Associations between sexual habits, menstrual hygiene practices, demographics and the vaginal microbiome as revealed by Bayesian network analysis

The vaginal microbiome plays an influential role in several disease states in reproductive age women, including bacterial vaginosis (BV). While demographic characteristics are associated with differences in vaginal microbiome community structure, little is known about the influence of sexual and hygiene habits. Furthermore, associations between the vaginal microbiome and risk symptoms of bacterial vaginosis have not been fully elucidated. Using Bayesian network (BN) analysis of 16S rRNA gene sequence results, demographic and extensive questionnaire data, we describe both novel and previously documented associations between habits of women and their vaginal microbiome. The BN analysis approach shows promise in uncovering complex associations between disparate data types. Our findings based on this approach support published associations between specific microbiome members (e.g., Eggerthella, Gardnerella, Dialister, Sneathia and Ruminococcaceae), the Nugent score (a BV diagnostic) and vaginal pH (a risk symptom of BV). Additionally, we found that several microbiome members were directly connected to other risk symptoms of BV (such as vaginal discharge, odor, itch, irritation, and yeast infection) including L. jensenii, Corynebacteria, and Proteobacteria. No direct connections were found between the Nugent Score and risk symptoms of BV other than pH, indicating that the Nugent Score may not be the most useful criteria for assessment of clinical BV. We also found that demographics (i.e., age, ethnicity, previous pregnancy) were associated with the presence/absence of specific vaginal microbes. The resulting BN revealed several as-yet undocumented associations between birth control usage, menstrual hygiene practices and specific microbiome members. Many of these complex relationships were not identified using common analytical methods, i.e., ordination and PERMANOVA. While these associations require confirmatory follow-up study, our findings strongly suggest that future studies of the vaginal microbiome and vaginal pathologies should include detailed surveys of participants' sanitary, sexual and birth control habits, as these can act as confounders in the relationship between the microbiome and disease. Although the BN approach is powerful in revealing complex associations within multidimensional datasets, the need in some cases to discretize the data for use in BN analysis can result in loss of information. Future research is required to alleviate such limitations in constructing BN networks. Large sample sizes are also required in order to allow for the incorporation of a large number of variables (nodes) into the BN, particularly when studying associations between metadata and the microbiome. We believe that this approach is of great value, complementing other methods, to further our understanding of complex associations characteristic of microbiome research.

The influence of maternal vaginal flora on the intestinal colonization in newborns and 3-month-old infants

AIM

The role of maternal vaginal bacteria on the colonization of neonatal gut is still a matter of discussion. Our aim was to estimate the role of maternal vaginal flora on the development of intestinal flora in neonates and 3-month-old infants.

METHODS

Seventy-nine maternal-neonatal pairs were included in the study. Vaginal swabs were taken before the rupture of membranes after admission to the delivery ward. First neonatal stool (meconium) and stool at 3-month-old infants were collected and cultured. All samples were subjected to microbiological analysis for Streptococcus, Staphylococcus, Bifidobacterium, Clostridium (including C. difficile), Lactobacillus, Escherichia coli, Klebsiella pneumoniae, and Candida.

RESULTS

Maternal vagina was colonized mainly by streptococci (67%) followed by lactobacilli (58%) and Candida spp. (39%). Vaginal streptococci influenced the intestinal colonization in infants with staphylococci, C. difficile, and candida.

CONCLUSION

Vaginal lactobacilli influenced colonization with C. difficile, and Candida. Vaginal flora is a potent factor influencing the development of bacterial flora in the neonatal and infantile gut. The extension of the observation period until 3 months of life allow to discover the potential changes in the intestinal flora of children.

Cervicovaginal cytokines, sialidase activity and bacterial load in reproductive-aged women with intermediate vaginal flora

Studies have shown that not only bacterial vaginosis, but also intermediate vaginal flora has deleterious effects for women's reproductive health. However, literature still lacks information about microbiological and immunological aspects of intermediate flora.

OBJECTIVE

To characterize intermediate flora regarding levels of Interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor-alpha, interleukin 1 receptor antagonist (IL-1ra), IL-10, sialidase; loads of Gardnerella vaginalis, total bacteria and to verify whether it is closer related to normal flora or bacterial vaginosis. This cross-sectional study enrolled 526 non-pregnant reproductive-aged women distributed in 3 groups according to pattern of vaginal flora using Nugent's system in normal, intermediate and bacterial vaginosis. Cervicovaginal levels of cytokines, sialidases, loads of G. vaginalis and total bacteria were assessed by ELISA, conversion of MUAN and quantitative real-time PCR, respectively. A principal component analysis(PCA) using all measured parameters was performed to compare the three different types of flora. Results showed that intermediate flora is associated with increased cervicovaginal IL-1beta in relation to normal flora(P<0.0001). When compared to bacterial vaginosis, intermediate flora has higher IL-8 and IL-10 levels(P<0.01). Sialidases were in significantly lower levels in normal and intermediate flora than bacterial vaginosis(P<0.0001). Loads of G. vaginalis and total bacterial differed among all groups(P<0.0001), being highest in bacterial vaginosis. PCA showed that normal and intermediate flora were closely scattered, while bacterial vaginosis were grouped separately.

CONCLUSION

Although intermediate flora shows some differences in cytokines, sialidases and bacterial loads in relation to normal flora and bacterial vaginosis, when taken together, general microbiological and immunological pattern pattern of intermediate flora resembles the normal flora.

Homogeneity of the vaginal microbiome at the cervix, posterior fornix, and vaginal canal in pregnant Chinese women

The vaginal microbiome is an emerging concern in prenatal health. Because the sampling process of vaginal microbiota may pose potential risks for pregnant women, the choice of sampling site should be carefully considered. However, whether the microbial diversity is different across various sampling sites has been controversial. In the present study, three repeated swabs were collected at the cervix (C), posterior fornix (P), and vaginal canal (V) from 34 Chinese women during different pregnancy stages, and vaginal species were determined using the Illumina sequencing of 16S rRNA tag sequences. The identified microbiomes were classified into four community state types (CSTs): CST I (dominated by L. crispatus), CST II (dominated by L. gasseri), CST III (dominated by L. iners), and CST IV-A (characterized by a low abundance of Lactobacillus, but with proportions of various species previously shown to be associated with bacterial vaginosis). All individuals had consistent CST at the three sampling sites regardless of pregnancy stage and CST group. In addition, there was little heterogeneity across community structures within each individual, as determined by LEfSe, indicating high vaginal microbiome homogeneity at the three sampling sites. The present study also revealed different beta diversity during pregnancy stages. The vaginal microbiome variation among women during trimester T1 (9 ± 2.6 weeks) is larger than that of non-pregnant women and women from other trimesters, as demonstrated by the UniFrac distance (P < 0.05). In particular, the present study is the first one that demonstrates the notably difference of vaginal microbiome of postpartum women compare to women in gestation. These results will be useful for future studies of the vaginal microbiota during pregnancy.

Diagnostic and therapeutic advancements for aerobic vaginitis

BACKGROUND

Aerobic vaginitis (AV) is a newly defined clinical entity that is distinct from candidiasis, trichomoniasis and bacterial vaginosis (BV). Because of the poor recognition of AV, this condition can lead to treatment failures and is associated with severe complications, such as pelvic inflammatory disease, infertility, preterm birth and foetal infections.

OBJECTIVE

This review describes the diagnosis and treatment of AV and the relationship between AV and pregnancy.

RESULTS

The characteristics of AV include severely depressed levels of lactobacilli, increased levels of aerobic bacteria and an inflamed vagina. The diagnosis is made by microscopy on wet mounts of fresh vaginal fluid, and some distinct clinical features are recognized. Vaginal suppositories that contain kanamycin or clindamycin have shown curative effects in nonpregnant women. Additionally, the application of topical probiotics can restore the vaginal flora and reduce the recurrence of AV. Clindamycin vaginal suppositories and probiotics may be a better choice for gravida with AV than metronidazole. AV requires prompt attention, and the early diagnosis and treatment of AV during pregnancy significantly improves perinatal outcomes.

CONCLUSION

Further research is needed to define the pathogenesis, diagnostic criteria and standard treatment guidelines for AV.

The vaginal microbiota and susceptibility to HIV

There is some evidence that the risk of HIV infection per heterosexual act is higher in low-income countries than in high-income countries. We hypothesize that variations in per sex-act transmission probability of HIV may in part be attributed to differences in the composition and function of the vaginal microbiota between different populations. This paper presents data that are in support of this hypothesis. Experimental and clinical studies have provided evidence that the normal vaginal microbiota plays a protective role against acquisition of HIV and other sexually transmitted infections. Epidemiological studies have convincingly shown that disturbances of the vaginal microbiome, namely intermediate flora and bacterial vaginosis, increase the risk of acquisition of HIV infection. A review of the literature found large differences in prevalence of bacterial vaginosis between different populations, with the highest prevalence rates found in black populations. Possible explanations for these differences are presented including data suggesting that there are ethnic differences in the composition of the normal vaginal microbiota. Lastly, interventions are discussed to restore and maintain a healthy vaginal environment.

Favorable outcomes for both mother and baby are possible in pregnant women with Crimean-Congo hemorrhagic fever disease: a case series and literature review

To assess the impact of Crimean-Congo hemorrhagic fever (CCHF) infection during pregnancy on maternal and fetal outcomes, we present the clinical and laboratory findings and outcomes of 5 pregnant women with CCHF infection as well as fetal outcomes. We also reviewed previously reported cases with CCHF infection in pregnant women. All pregnant women with CCHF infection who had been hospitalized between August 2007 and September 2011 were included. The gestational ages at the time of CCHF infection were 8, 18, 20, 21 and 32 weeks. CCHF infection was acquired during the 1st trimester in only 1 case and resulted in spontaneous abortion. The other 4 pregnant women completely recovered, all reached a healthy full-term gestation and 4 term babies were born. All infants had normal birth weight and were found to be healthy on their first examination and follow-up. In the literature concerning CCHF infection in pregnancy, 8 published articles including case reports or case series and 1 poster presentation including 1 case could be accessed. In conclusion, there is a risk of vertical transmission of CCHF infection, and infections acquired early in gestation had a poor prognosis for the fetus.

Basic vaginal pH, bacterial vaginosis and aerobic vaginitis: prevalence in early pregnancy and risk of spontaneous preterm delivery, a prospective study in a low socioeconomic and multiethnic South American population

Background

Bacterial vaginosis (BV) increases the risk of spontaneous preterm deliveries (PD) in developed countries. Its prevalence varies with ethnicity, socioeconomic conditions and gestational age. Aerobic vaginitis (AV) has also been implicated with spontaneous PD. The present study aimed to estimate the prevalence of asymptomatic BV, the accuracy of vaginal pH level to predict BV and to estimate the risk of spontaneous PD <34 and <37 weeks’ gestation of BV and AV.

Methods

Women attending prenatal public services in Rio de Janeiro were screened to select asymptomatic pregnant women, < 20 weeks’ gestation, with no indication for elective PD and without risk factors of spontaneous PD. Vaginal smears of women with vaginal pH > = 4.5 were collected to determine the Nugent score; a sample of those smears was also classified according to a modified Donders’ score. Primary outcomes were spontaneous PD < 34 and <37 weeks’ gestation and abortion.

Results

Prevalence of asymptomatic BV was estimated in 28.1% (n = 1699); 42.4% of the smears were collected before 14 weeks’ gestation. After an 8-week follow up, nearly 40% of the initially BV positive women became BV negative. The prevalence of BV among white and black women was 28.1% (95% CI: 24.6%-32.0%) and 32.5% (95% CI: 28.2%-37.2%), respectively. The sensitivity of vaginal pH= > 4.5 and = > 5.0 to predict BV status was 100% and 82%, correspondingly; the 5.0 cutoff value doubled the specificity, from 41% to 84%. The incidence of < 37 weeks’ spontaneous PDs among BV pregnant women with a pH= > 4.5 was 3.8%. The RR of spontaneous PD < 34 and <37 weeks among BV women with pH > =4.5, as compared with those with intermediate state, were 1.24 and 1.86, respectively (Fisher’s exact test, p value = 1; 0.52, respectively, both ns). No spontaneous case of PD or abortion was associated with severe or moderate AV.

Conclusions

A high prevalence of asymptomatic BV was observed without statistically significant difference between black and white women. The RRs of spontaneous PD < 34 and <37 weeks among women with BV, as compared with those with intermediate state were not statistically significant but were consistent with those found in the literature.

The global epidemiology of bacterial vaginosis: a systematic review

Bacterial vaginosis (BV) enhances the acquisition and transmission of a range of sexually transmitted infections including human immunodeficiency virus. This has made it more important to uncover the reasons why some populations have very high BV prevalences and others not. This systematic review describes the global epidemiology of BV. It summarizes data from peer-reviewed publications detailing the population prevalence of BV as diagnosed by a standardized and reproducible methodology-Nugent scoring system. BV variations between countries, and between ethnic groups within countries, are described. We evaluated 1692 English- and non-English-language articles describing the prevalence of BV using MEDLINE and the Web of Science databases. A total of 86 articles met our inclusion criteria. BV prevalences were found to vary considerably between ethnic groups in North America, South America, Europe, the Middle East, and Asia. Although BV prevalence is, in general, highest in parts of Africa and lowest in much of Asia and Europe, some populations in Africa have very low BV prevalences and some in Asia and Europe have high rates.

Intravaginal rings as delivery systems for microbicides and multipurpose prevention technologies

There is a renewed interest in delivering pharmaceutical products via intravaginal rings (IVRs). IVRs are flexible torus-shaped drug delivery systems that can be easily inserted and removed by the woman and that provide both sustained and controlled drug release, lasting for several weeks to several months. In terms of women's health care products, it has been established that IVRs effectively deliver contraceptive steroids and steroids for the treatment of postmenopausal vaginal atrophy. A novel application for IVRs is the delivery of antiretroviral drugs for the prevention of human immunodeficiency virus (HIV) genital infection. Microbicides are antiviral drugs delivered topically for HIV prevention. Recent reviews of microbicide IVRs have focused on technologies in development and optimizing ring design. IVRs have several advantages, including the ability to deliver sustained drug doses for long periods of time while bypassing first pass metabolism in the gut. IVRs are discreet, woman-controlled, and do not require a trained provider for placement or fitting. Previous data support that women and their male sexual partners find IVRs highly acceptable. Multipurpose prevention technology (MPT) products provide protection against unintended/mistimed pregnancy and reproductive tract infections, including HIV. Several MPT IVRs are currently in development. Early clinical testing of new microbicide and MPT IVRs will require a focus on safety, pharmacokinetics and pharmacodynamics. Specifically, IVRs will have to deliver tissue concentrations of drugs that are pharmacodynamically active, do not cause mucosal alterations or inflammation, and do not change the resident microbiota. The emergence of resistance to antiretrovirals will need to be investigated. IVRs should not disrupt intercourse or have high rates of expulsion. Herein, we reviewed the microbicide and MPT IVRs currently in development, with a focus on the clinical aspects of IVR assessment and the challenges facing microbicide and MPT IVR product development, clinical testing, and implementation. The information in this review was drawn from PubMed searches and a recent microbicide/MPT product development workshop organized by CONRAD.

Pregnancy-induced changes in immune protection of the genital tract: defining normal

OBJECTIVE

Both the state of pregnancy as well as disruption of vaginal flora and immune mediators may increase the risk of human immunodeficiency virus-1 acquisition. The objective of this study was to define immune changes in lower genital and systemic immunity associated with normal pregnancy.

STUDY DESIGN

This prospective cohort enrolled low-risk pregnant and nonpregnant women ages 18-35 years. Pregnant women at <14 weeks and nonpregnant women in follicular phase of the menstrual cycle were included. Cervical and vaginal fluid was collected. Concentrations of immune mediators were measured using enzyme-linked immunosorbent assay-based methods or multiplex immunoassay. Samples were inoculated onto various culture media allowing for growth of Lactobacillus species, Gardnerella vaginalis, Escherichia coli, Enterococcus species, anaerobic gram-negative rods, Candida, Staphylococcus aureus, Ureaplasma species, and Mycoplasma hominis. Concentrations of immune mediators and vaginal colonization frequencies were compared between the pregnant and nonpregnant groups.

RESULTS

Genital tract concentration of interleukin-1β was higher during pregnancy compared to nonpregnant participants. Serum C-reactive protein concentrations were higher in all trimesters of pregnancy. Concentrations of secretory leukocyte protease inhibitor did not differ between groups. Lactobacillus was more commonly isolated from vaginal cultures of nonpregnant participants (100% vs 70.2%, P = .02). Identification of Candida, G vaginalis, M hominis, and S aureus was common and not different between groups. Ureaplasma species was isolated from >60% pregnant participants.

CONCLUSION

The proinflammatory cytokine, interleukin-1β, as well as the systemic marker of inflammation, C-reactive protein, are increased during pregnancy. The impact of these proinflammatory changes during pregnancy deserves further study.

Prevalence and treatment of aerobic vaginitis among non-pregnant women: evaluation of the evidence for an underestimated clinical entity

We sought to evaluate the evidence on the prevalence of aerobic vaginitis (AV) among symptomatic non-pregnant women, as well as the treatment administered for this clinical entity. The PubMed and Scopus databases were systematically searched. Sixteen studies met the inclusion criteria, 11 of which reported on the prevalence of possible AV, two on the prevalence of diagnosed AV, and three on the treatment and outcomes of women with diagnosed AV. The prevalence of diagnosed AV varied from 5 to 10.5 %. Streptococcus spp., Staphylococcus aureus, and coagulase-negative staphylococci were the most commonly identified Gram-positive pathogens among women with possible AV, with prevalences of up to 58.7, 41.7, and 37.4 %, respectively, while Escherichia coli was the most common Gram-negative pathogen identified, with a prevalence of up to 23 % among symptomatic women. Regarding antibiotic treatment for AV, the antibiotic schemes administered, which mainly consisted of suppositories of aminoglycosides, showed good effectiveness without serious adverse events provided by any of the included studies. The currently available data suggest that the prevalence of AV is not negligible, while the prevalence of possible AV is considerable. Well-designed studies comparing the prevalence of aerobic pathogens between symptomatic and asymptomatic women are warranted.

Efficacy of methods used for the diagnosis of bacterial vaginosis

INTRODUCTION

Bacterial vaginosis (BV) has been associated with pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. Diagnosis of BV should be rapid, reliable and safe. This is especially vital in pregnant women where intervention may be necessary for the well-being of both the mother and the foetus.

AREAS COVERED

This paper consulted PUBMED, LISTA and Web of Science for point-of-care and laboratory-based tests commonly used for the diagnosis and management of BV in pregnant women. An overview of strengths and weaknesses of the methods used may partially explain why treatment plans have failed. Differences in sampling and detection methods, time of gestation, inter-examiner variability and interpretation of data, and the use of different reference tests, amongst many other factors, complicated a meta-analysis of the data.

EXPERT OPINION

Inconsistencies found in clinical and laboratory detection methods used for the monitoring of treatment have a direct impact on success rates. With current advances in technology, the diagnosis of BV is taking on a new perspective. New information implicating specific vaginal biofilms in adverse pregnancy outcomes through the application of advanced technology promises to change the way we view the aetiology, diagnosis and management of BV.