Jeanne M. Marrazzo

Tenofovir-Based Preexposure Prophylaxis for HIV Infection among African Women

BACKGROUND Reproductive-age women need effective interventions to prevent the acquisition of human immunodeficiency virus type 1 (HIV-1) infection. METHODS We conducted a randomized, placebo-controlled trial to assess daily treatment with oral tenofovir disoproxil fumarate (TDF), oral tenofovir-emtricitabine (TDF-FTC), or 1% tenofovir (TFV) vaginal gel as preexposure prophylaxis against HIV-1 infection in women in South Africa, Uganda, and Zimbabwe. HIV-1 testing was performed monthly, and plasma TFV levels were assessed quarterly. RESULTS Of 12,320 women who were screened, 5029 were enrolled in the study. The rate of retention in the study was 91% during 5509 person-years of follow-up. A total of 312 HIV-1 infections occurred; the incidence of HIV-1 infection was 5.7 per 100 person-years. In the modified intention-to-treat analysis, the effectiveness was -49.0% with TDF (hazard ratio for infection, 1.49; 95% confidence interval [CI], 0.97 to 2.29), -4.4% with TDF-FTC (hazard ratio, 1.04; 95% CI, 0.73 to 1.49), and 14.5% with TFV gel (hazard ratio, 0.85; 95% CI, 0.61 to 1.21). In a random sample, TFV was detected in 30%, 29%, and 25% of available plasma samples from participants randomly assigned to receive TDF, TDF-FTC, and TFV gel, respectively. Independent predictors of TFV detection included being married, being older than 25 years of age, and being multiparous. Detection of TFV in plasma was negatively associated with characteristics predictive of HIV-1 acquisition. Elevations of serum creatinine levels were seen more frequently among participants randomly assigned to receive oral TDF-FTC than among those assigned to receive oral placebo (1.3% vs. 0.2%, P=0.004). We observed no significant differences in the frequencies of other adverse events. CONCLUSIONS None of the drug regimens we evaluated reduced the rates of HIV-1 acquisition in an intention-to-treat analysis. Adherence to study drugs was low. (Funded by the National Institutes of Health; VOICE ClinicalTrials.gov number, NCT00705679.).

Bacterial Communities in Women with Bacterial Vaginosis: High Resolution Phylogenetic Analyses Reveal Relationships of Microbiota to Clinical Criteria

Background Bacterial vaginosis (BV) is a common condition that is associated with numerous adverse health outcomes and is characterized by poorly understood changes in the vaginal microbiota. We sought to describe the composition and diversity of the vaginal bacterial biota in women with BV using deep sequencing of the 16S rRNA gene coupled with species-level taxonomic identification. We investigated the associations between the presence of individual bacterial species and clinical diagnostic characteristics of BV. Methodology/Principal Findings Broad-range 16S rRNA gene PCR and pyrosequencing were performed on vaginal swabs from 220 women with and without BV. BV was assessed by Amsel’s clinical criteria and confirmed by Gram stain. Taxonomic classification was performed using phylogenetic placement tools that assigned 99% of query sequence reads to the species level. Women with BV had heterogeneous vaginal bacterial communities that were usually not dominated by a single taxon. In the absence of BV, vaginal bacterial communities were dominated by either Lactobacillus crispatus or Lactobacillus iners. Leptotrichia amnionii and Eggerthella sp. were the only two BV-associated bacteria (BVABs) significantly associated with each of the four Amsel’s criteria. Co-occurrence analysis revealed the presence of several sub-groups of BVABs suggesting metabolic co-dependencies. Greater abundance of several BVABs was observed in Black women without BV. Conclusions/Significance The human vaginal bacterial biota is heterogeneous and marked by greater species richness and diversity in women with BV; no species is universally present. Different bacterial species have different associations with the four clinical criteria, which may account for discrepancies often observed between Amsel and Nugent (Gram stain) diagnostic criteria. Several BVABs exhibited race-dependent prevalence when analyzed in separate groups by BV status which may contribute to increased incidence of BV in Black women. Tools developed in this project can be used to study microbial ecology in diverse settings at high resolution.

Targeted PCR for Detection of Vaginal Bacteria Associated with Bacterial Vaginosis

ABSTRACT Several novel bacterial species have been detected in subjects with bacterial vaginosis (BV) by using broad-range PCR assays, but this approach is insensitive for detecting minority species. We developed a series of taxon-directed 16S rRNA gene PCR assays for more sensitive detection of key vaginal bacteria. We sought to determine the prevalence of each species in the vagina, its association with BV, and the utility of PCR for the microbiological diagnosis of BV. Targeted PCR assays were developed for 17 vaginal bacterial species and applied to 264 vaginal-fluid samples from 81 subjects with and 183 subjects without BV. The results were compared to those of two widely accepted methods for diagnosing BV, the use of clinical findings (Amsel criteria) and the interpretation of vaginal-fluid Gram stains (Nugent criteria). Leptotrichia/Sneathia, Atopobium vaginae, an Eggerthella-like bacterium, Megasphaera species, and three novel bacteria in the order Clostridiales are among the bacterial species significantly associated with BV. PCR detection of either a Megasphaera species or one of the Clostridiales bacteria yielded a sensitivity of 99% and a specificity of 89% for diagnosis of BV compared to the Amsel clinical criteria and a sensitivity of 95.9% and a specificity of 93.7% compared to the Nugent criteria (Gram stain). PCR detection of one or more fastidious bacterial species is a more reliable indicator of BV than detection of bacteria, such as Gardnerella vaginalis, previously linked to BV, highlighting the potential of PCR for the diagnosis of BV.

Temporal Variability of Human Vaginal Bacteria and Relationship with Bacterial Vaginosis

Background Little is known about short-term bacterial fluctuations in the human vagina. This study used PCR to assess the variability in concentrations of key vaginal bacteria in healthy women and the immediate response to antibiotic treatment in women with bacterial vaginosis (BV). Methodology/Principal Findings Twenty-two women assessed for BV using Amsels criteria were evaluated daily for 7 or 14 days, then at 2, 3 and 4 weeks, using a panel of 11 bacterium-specific quantitative PCR assays. Participants with BV were treated with 5 days of intravaginal metronidazole. Participants without BV had vaginal biotas dominated by lactobacilli, whose levels fluctuated with menses. With onset of menstruation, quantities of Lactobacillus jensenii and Lactobacillus crispatus decreased and were found to be inversely related to Gardnerella vaginalis concentrations (p<0.001). Women with BV had a variety of fastidious bacteria whose concentrations dropped below detection thresholds 1–5 days after starting metronidazole. Recurrent BV was characterized by initial profound decreases of BV-associated bacteria after treatment followed by subsequent increases at relapse. Conclusions/Significance The microbiota of the human vagina can be highly dynamic. Healthy women are colonized with Lactobacillus species, but levels can change dramatically over a month. Marked increases in G. vaginalis were observed during menses. Participants with BV have diverse communities of fastidious bacteria that are depleted by vaginal metronidazole therapy. Women with recurrent BV initially respond to antibiotic treatment with steep declines in bacterial concentrations, but these bacteria later reemerge, suggesting that antibiotic resistance in these bacteria is not an important factor mediating BV recurrence.

Characterization of Vaginal Flora and Bacterial Vaginosis in Women Who Have Sex with Women

Bacterial vaginosis (BV) may be common among women who report having sex with women (WSW) and frequently occurs in both members of monogamous couples. The results of Gram staining of a vaginal smear were consistent with BV in 81 (25%) and intermediate in 37 (11%) of 326 WSW included in this study. Lactobacilli were detected in 64% of subjects, and 42% of subjects had H(2)O(2)-producing strains. BV was associated with a higher lifetime number of female sex partners, failure to always clean an insertive sex toy before use, and oral-anal sex with female partners. Neither recent douching nor sexual practices with male partners were associated with BV. Vaginal smears from each partner were concordant in 55 (95%) of 58 monogamous couples; BV was present in both partners in 16 couples (28%) (P<.001, compared with expected distribution). BV was common among subjects who did not douche, who did not have concurrent sex with male partners, or who did not have a new sex partner, which suggests that other risk factors for BV exist. These data support the hypothesis that sexual exchange of vaginal secretions is a possible mechanism for acquisition of BV.

Diversity of Human Vaginal Bacterial Communities and Associations with Clinically Defined Bacterial Vaginosis

ABSTRACT Bacterial vaginosis (BV) is a common syndrome associated with numerous adverse health outcomes in women. Despite its medical importance, the etiology and microbial ecology of BV remain poorly understood. We used broad-range PCR to census the community structure of the healthy and BV-affected vaginal microbial ecosystems and synthesized current publicly available bacterial 16S rRNA gene sequence data from this environment. The community of vaginal bacteria detected in subjects with BV was much more taxon rich and diverse than in subjects without BV. At a 97% sequence similarity cutoff, the number of operational taxonomic units (OTUs) per patient in 28 subjects with BV was nearly three times greater than in 13 subjects without BV: 14.8 ± 0.7 versus 5.2 ± 0.75 (mean ± standard error). OTU-based analyses revealed previously hidden diversity for many vaginal bacteria that are currently poorly represented in GenBank. Our sequencing efforts yielded many novel phylotypes (123 of our sequences represented 38 OTUs not previously found in the vaginal ecosystem), including several novel BV-associated OTUs, such as those belonging to the Prevotella species complex, which remain severely underrepresented in the current NCBI database. Community composition was highly variable among subjects at a fine taxonomic scale, but at the phylum level, Actinobacteria and Bacteroidetes were strongly associated with BV. Our data describe a previously unrecognized extent of bacterial diversity in the vaginal ecosystem. The human vagina hosts many bacteria that are only distantly related to known species, and subjects with BV harbor particularly taxon-rich and diverse bacterial communities.

PERFORMANCE AND COST-EFFECTIVENESS OF SELECTIVE SCREENING CRITERIA FOR CHLAMYDIA TRACHOMATIS INFECTION IN WOMEN. IMPLICATIONS FOR A NATIONAL CHLAMYDIA CONTROL STRATEGY

Background and Objectives: Detection of subclinical Chlamydia trachomatis infection in women is a high but costly public health priority. Goals: To develop and test simple selective screening criteria for chlamydia in women, to assess the contribution of cervicitis to screening criteria, and to evaluate cost‐effectiveness of selective versus universal screening. Study Design: Cross‐sectional study and cost‐effectiveness analysis of 11,141 family planning (FP) and 19,884 sexually transmitted diseases (STD) female clients in Washington, Oregon, Alaska, and Idaho who were universally tested for chlamydia using cell culture, direct fluorescent antibody, enzyme immunoassay, or DNA probe. Results: Prevalence of cervical chlamydial infection was 6.6%. Age younger than 20 years, signs of cervicitis, and report of new sex partner, two or more partners, or symptomatic partner were independent predictors of infection. Selective screening criteria consisting of age 20 years or younger or any partner‐related risk detected 74% of infections in FP clients and 94% in STD clients, and required testing 53% of FP and 77% of STD clients. Including cervicitis in the screening criteria did not substantially improve their performance. Universal screening was more cost‐effective than selective screening at chlamydia prevalences greater than 3.1% in FP clients and greater than 7% in STD clients. Conclusions: Age and behavioral history are as sensitive in predicting chlamydial infection as criteria that include cervicitis. Cost‐effectiveness of selective screening is strongly influenced by the criterias sensitivity in predicting infection, which was significantly higher in STD clients. At the chlamydia prevalences in the populations studied, it would be cost saving to screen universally in FP clinics and selectively in STD clinics, the reverse of current practice in many locales.

Changes in Vaginal Bacterial Concentrations with Intravaginal Metronidazole Therapy for Bacterial Vaginosis as Assessed by Quantitative PCR

Several fastidious bacteria have been associated with bacterial vaginosis (BV) using broad-range bacterial PCR methods such as consensus sequence 16S rRNA gene PCR, but their role in BV remains poorly defined. We describe changes in vaginal bacterial concentrations following metronidazole therapy for BV. Vaginal swabs were collected from women with BV diagnosed using Amsel clinical criteria, and vaginal fluid was assessed by Gram stain to generate Nugent scores. Follow-up swabs were collected 1 month after a 5-day course of vaginal 0.75% metronidazole gel and analyzed for 24 subjects with cured BV and 24 subjects with persistent BV. Changes in bacterial concentrations were measured using eight bacterium-specific 16S rRNA gene quantitative PCR assays. DNA from several fastidious BV-associated bacteria (BVAB) were present at high concentrations in the vagina prior to treatment. Successful antibiotic therapy resulted in 3- to 4-log reductions in median bacterial loads of BVAB1 (P = 0.02), BVAB2 (P = 0.0004), BVAB3 (P = 0.03), a Megasphaera-like bacterium (P < 0.0001), Atopobium species (P < 0.0001), Leptotrichia/Sneathia species (P = 0.0002), and Gardnerella vaginalis (P < 0.0001). Median posttreatment bacterial levels did not change significantly in subjects with persistent BV except for a decline in levels of BVAB3. The presence or absence of BV is reflected by vaginal concentrations of BV-associated bacteria such as BVAB1, BVAB2, Leptotrichia/Sneathia species, Atopobium species, Gardnerella vaginalis, and a Megasphaera-like bacterium, suggesting that these bacteria play an important role in BV pathogenesis and may be suitable markers of disease and treatment response.

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

ABSTRACT Tests for Chlamydia trachomatis and Neisseria gonorrhoeae, which can provide results rapidly to guide therapeutic decision-making, offer patient care advantages over laboratory-based tests that require several days to provide results. We compared results from the Cepheid GeneXpert CT/NG (Xpert) assay to results from two currently approved nucleic acid amplification assays in 1,722 female and 1,387 male volunteers. Results for chlamydia in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, and for urine samples from males, a sensitivity of 97.5%, with all specificity estimates being ≥99.4%. Results for gonorrhea in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, and for urine samples from males, a sensitivity of 98.0%, with all estimates of specificity being ≥99.8%. These results indicate that this short-turnaround-time test can be used to accurately test patients and to possibly do so at the site of care, thus potentially improving chlamydia and gonorrhea control efforts.

Bacterial vaginosis: identifying research gaps proceedings of a workshop sponsored by DHHS/NIH/NIAID.

The microbiota of the human vagina can affect the health of women, their fetuses, and newborns. Bacterial vaginosis (BV) is the most prevalent form of vaginal infection in women of reproductive age, affecting 8% to 23%, and is the most common etiology of vaginal symptoms prompting women to seek medical care. While traditional cultivation has identified numerous BV-associated bacteria involved in these processes, recent advances in molecular biology have facilitated the detection and identification of bacteria without cultivation, some of which have not previously been described or well characterized. A more complete understanding of vaginal microbial populations resulting from the adoption of molecular tools may lead to better strategies to maintain healthy vaginal microbial communities—thus enhancing womens health—and will create opportunities to explore the role of novel bacteria in reproductive tract diseases. On November 19–20, 2008, the NIH convened a workshop of experts in the field of research and clinical practice related to BV in order to discuss how these new advances should be interpreted and applied to research in progress and collaborations between relevant disciplines. This paper summarizes the presentations of this workshop and outlines general recommendations arising from the related discussions. Future studies of BV and its associated adverse outcomes should determine if specific combinations of organisms are more pathogenic than others, and causally associated with different adverse events. Moreover, determination of causality will depend not only on more precise categorization of the vaginal microbiota, but also on variations in the host environment that may be associated with changes in bacterial communities over time. In this report, we offer suggestions and recommendations that we hope will facilitate conduct of consistent approaches to collaborative efforts towards advancing our understanding of the vaginal microbiota and its impact on human health.