The human papillomavirus (HPV) causes cervical cancer in only a small proportion of women infected by the virus. To better understand why those women develop cervical cancer, Robert Burk, M.D., and colleagues focused on women participating in an HPV vaccine trial in Costa Rica. They looked for features of the cervicovaginal microbiome associated with cervical precancer.

In a paper published online on March 26 in PLOS Pathogens, the researchers reported that elevated levels of the bacterium Gardnerella vaginalis can be detected in the cervix years before precancerous cells develop and is associated with elevated microbial diversity of the vaginal microbiome and with cervical precancer. They also found that having elevated levels of Lactobacillus species, as well as increased diversity of certain fungi, may suppress the elevated vaginal microbial diversity associated with Gardnerella vaginalis and prevent the subsequent progression to cervical precancer. The findings suggest that assessing the vaginal microbiome could help identify those women at higher risk for maintaining a persistent HPV infection and developing cervical cancer. The findings could especially help women living in developing countries that have not adopted the HPV vaccine and where cervical cancer remains a public health burden.

Dr. Burk, the paper’s senior author, is professor of pediatrics, of microbiology & immunology, of epidemiology & public health, of obstetrics & gynecology and women’s health at Einstein, and an attending physician at Montefiore. First author is Mykhaylo Usyk, B.S., M.S., a senior bioinformatics analyst in Dr. Burk’s lab.