A Persistent(ly) Enigmatic Ecological Mystery: Bacterial Vaginosis

Considering the vagina's central role in women's susceptibility to acquiring sexually transmitted infections (STIs), including HIV, we have a remarkably limited understanding of its microflora and mucosal immunology. We have known for >2 decades that the "normal" vagina is dominated by hydrogen peroxide-producing Lactobacillus species, particularly L. crispatus and L. jensenii [1]. Quantitative declines in numbers of these vaginal lactobacilli have been associated with an increased risk of the acquisition of bacterial vaginosis (BV) [2], gonorrhea [3], and HIV infection [3] and with cervicitis [4]. BV itself, in which the relative lack of lactobacilli is accompanied by a profound increase in the quantity of vaginal anaerobic bacteria, has been associated with an increased risk of some STIs [5] and HIV infection [6, 7]. BV is the most prevalent vaginal infection in women of reproductive age-it affects 8%-23% of women and is the most common cause of vaginal symptoms prompting women to seek medical care. Despite this, our collective