How infections occur
Infections can occur when conditions adversely affect certain species, allowing others to outcompete the usually healthy lactobacilli.1 Factors commonly associated with vaginitis are: antibiotics disturbing the healthy microbiota; physiological changes brought about by pregnancy; and poorly-controlled diabetes influencing hormonal levels.7
Immunosuppressed women are also at increased risk, and some people have an individual susceptibility.4,8
Contraceptives, spermicides and frequent sexual intercourse, especially if the vagina is dry, are also possible triggers.4 Intrauterine devices (IUDs) and vaginal douching are associated with BV.
Subsequent problems include increased risks of urinary tract infections,9 pre-term delivery in pregnancy, and susceptibility to a number of sexually-transmitted organisms.2