Having sex with a person that does not have any type of yeast infection will not induce a yeast infection. Sexual activity, by itself, cannot cause a yeast infection; however, if one of the two people involved in sexual activity has a yeast infection of some kind, it can be transmitted to the other person. Therefore, if neither partner has a yeast infection, it will be impossible for one partner to pass it to another.
Yeast infections are caused by microscopic fungus that invade the body. The specific species responsible for the majority of vaginal and oral yeast infections is known as Candida albicans. Fungal mycosis of the vagina and mouth can also be caused by Candida glabrata, although it is not as common as mycosis caused by Candida albicans. Candida glabrata is a highly opportunistic pathogen that attacks people with compromised immune systems. Candida glabrata can often attack individuals who have the Human immunodeficiency virus (HIV) and the elderly.
Yeast are normally resides in approximately 80% of human beings without causing any malicious health maladies. Yeast can be found on the skin of adult humans and are part of the normal microbiota of the vagina, gastrointestinal tract, and respiratory system. For a yeast infection to occur, yeast must multiply unrestrained to the point where the fungus causes problems for its host; e.g., the typical signs and symptoms associated with a yeast infection (learn more about yeast infection signs and symptoms).
As mentioned earlier, yeast is quite ubiquitous, existing in many different parts of the human body. Although some microscopic yeast can be transferred during sex from your partner’s skin to your vagina, it should not be a problem. There is already a very tiny amount of yeast that is living in your vagina anyway and there is nothing you can do to fully eliminate yeast from your vagina, it is too ubiquitous. Consequently, having your sex partner add a few microscopic yeast organisms to your body will not induce a yeast infection. Every time you touch another individual’s skin, you are potentially picking up a minuscule amount of yeast.
If Sex Does not Cause a Yeast Infection, what Does?
This website has an entire page dedicated to this question and covers some contraceptives that have been shown to induce yeast overgrowth. Feel free to learn more about what actually does cause a yeast infection at this page: yeast infection causes.