No, yeast infections are not sexually transmitted, with rare exceptions. Yeast is a kind of fungus. Various species of yeasts/fungi (e.g., Candida and others) are normally present on and around various parts of the body, including the rectum and vagina; most
womenWomen's way carry yeasts some of the time and in some
womenWomen's way they are always present. In other words, when a "yeast infection" occurs, it isn't that the yeast has newly arrived; it has been there all the time. The reasons yeasts grow to larger amoungs, or that your body reacts to them with irritation, are quite varied and often aren't known--although hormonal fluctuations, changes in other bacteria in the vagina (e.g., after antibiotic therapy for another infection).
Having said all that, there are exceptions. Occasionally a man may get a
penileCancer - penis yeast infection by exposure to a
womanWomen's way with
vaginalAnterior vaginal wall repair
Causes of vaginal itching
Culture - endocervix
Hydrocele
Hysterectomy
Transvaginal ultrasound
Vaginal bleeding between periods
Vaginal bleeding during pregnancy
Vaginal bleeding in pregnancy
Vaginal cysts
Vaginal discharge yeast; and on very rare occasion, a woman may acquire infection from a male partner.
I hope this helps. Regards-- HHH, MD