Women who develop bacterial vaginosis (BV) often later acquire chlamydia, a common and potentially serious sexually transmitted bacterial infection. Now, researchers at Albert Einstein College of Medicine, Roswell Park Comprehensive Cancer Center, and the Icahn School of Medicine at Mount Sinai have found that BV actually consists of two subtypes—one of which significantly increases the risk of developing chlamydia infections.
The findings were made in a population of young Black and Hispanic women, who are disproportionately affected by both BV and chlamydia, but are historically understudied. The study, one of the largest and most comprehensive of its kind, was published online today in the journal Cell.
BV is caused by imbalances in the cervicovaginal microbiome—the collection of bacteria naturally found in the genital tract. Common symptoms include vaginal discharge, itching or irritation, and burning sensation during urination, although many cases are asymptomatic. BV can be readily treated with antibiotics.
In the new study, the researchers used advanced DNA-sequencing technology to analyze the cervicovaginal microbiomes of 560 adolescent and young adult Black and Hispanic females. The analyses were performed before infection with chlamydia, at the time of infection, and following antibiotic treatment, allowing the researchers to identify which combination of cervicovaginal bacteria is associated with subsequent chlamydia infections.
The analysis detected two distinct subtypes of BV. One subtype—a collection of ten different interconnected bacterial types that account for about 40% of all BV cases—contributed to increased risk for acquiring chlamydia, subsequent reinfection with chlamydia, and complications such as pelvic inflammatory disease.
