Vaginal yeast infections or bacterial vaginosis (BV) are not considered sexually transmitted infections. However, during intercourse, microorganisms, and semen introduced from the male partner can cause interruption of the balance in the vaginal ecological system, in which indigenous bacteria and Candida yeast exist. When bad bacteria or yeast overgrow in the vagina, infections occur. The source of bad bacteria or yeast could be from the partner or previously indigenous to the woman. You may find these two articles helpful:
Men rarely get yeast infections and they do not get BV. At least, they do not show symptoms. However, this does not mean they cannot be a carrier. If you are sexually active and you are suffering from recurrent yeast or BV, the chance is high that your partner may also be infected and become a carrier. Even though men do not show symptoms, men can pass yeast or BV back to women. This may be one of the reasons that cause yeast or BV to recur.
We suggest that during and after your treatment, you should refrain from having intercourse for at least two weeks. The Candida yeast or BV in the male partner can be flushed out with time. A 2-week flushing period may be needed to flush out most carried microorganisms in the male partner.