The microbiota of the human vagina can affect the health of women, their fetuses, and newborns. A vaginal environment that is quantitatively dominated by hydrogen peroxide-producing Lactobacillus species has consistently been associated with healthy pregnancy outcomes, lack of abnormal vaginal symptoms, and reduced risk for several sexually transmitted pathogens, including HIV. Bacterial vaginosis (BV) represents a condition in which the normal protective lactobacilli are replaced by high quantities of commensal anaerobes, resulting in symptomatic vaginitis in many women. BV increases the risk of upper genital tract infection and adverse outcomes of pregnancy. 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. For instance, several novel bacteria in the Clostridiales order are highly specific indicators of bacterial vaginosis (BV), and bacteria related to Megasphaera, Leptotrichia, Atopobium, and Dialister species are commonly found in subjects with BV. These advances have notable implications for research related to the pathogenesis, natural history, diagnosis and adverse consequences of BV. 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 women’s 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. The group discussed numerous questions. What do we know about pathogenesis, and what are the gaps in our knowledge (Table 1)? What are the consequences of BV, and what are the gaps in our understanding regarding how these complications arise? What interventions have and have not worked to prevent these consequences, and how do we leverage this knowledge to move forward with appropriate prevention strategies? How might advances in molecular biology contribute to an enhanced approach to diagnosing BV? Experts in the field summarized the current status of BV-related research in three main areas: epidemiology and adverse consequences of BV; diagnosis and treatment; and molecular advances in defining BV-related microbiology. Workgroups focused on these three main areas then met to deliberate about key challenges and questions. This paper summarizes the presentations of this workshop and outlines general recommendations arising from the related discussions.