The global health impact of vaginal dysbiosis.

The most common dysbiosis of the vaginal microbiome (defined here as a vaginal microbiome not dominated by lactobacilli) is bacterial vaginosis, an anaerobic polybacterial dysbiosis. Other dysbiotic states of importance to global health are vaginal microbiota with a high abundance of streptococci, staphylococci or Enterobacteriaceae, vaginal candidiasis and trichomoniasis. Knowledge about the different types of dysbiosis and their relationship to urogenital and reproductive disease burden has increased in recent years by applying non-culture-based techniques, but is far from complete. The burden of bacterial vaginosis is highest in sub-Saharan Africa and in women of sub-Saharan African descent living elsewhere. Vaginal dysbiosis has been associated with increased susceptibility to and transmission of HIV and other sexually transmitted infections and increased risk of pelvic inflammatory disease, preterm birth and maternal and neonatal infections. In this review, we summarize the contribution of vaginal dysbiosis to the global burden of each of these and highlight areas that require more research.