A 2003 study finds that the presence of yeast in male sex partners does not make women more prone to recur yeast infections. But certain sex acts might.
Many doctors, and many women, believe that women get recurrent yeast infections because their partner passes the yeast back to them during intercourse. "This study refuses that belief," says study author, Barbara Reed, MD, MSPH, professor of Family Medicine at the UM Medical School. "This study suggests the risk for recurrent infections is related to something else – perhaps the woman's immune response to the yeast."
Candida vulvovaginitis, or yeast infection, is one of the most common diagnoses in American women. About three-quarters of women will have at least one yeast infection in their lives, and 40% have recurrent infections. The Candida yeast is often found in both women and men in the genital area, rectum, and mouth.
In the study, published in the December Journal of Women's Health, researchers looked at 148 women with confirmed Candida vulvovaginitis and 78 of their male sexual partners. Each woman was examined by a doctor, who collected samples from the vagina, cervix, vulva, tongue, and rectum. The men were asked to collect at- home urine, fecal, and semen samples, and a tongue swabbing. The samples were analyzed by culture to determine whether Candida species were present at each site.
The women received treatment for their initial infection and were asked to return for follow-up visits after two weeks, four weeks, six months, and a year. At each visit, they were asked about symptoms, sexual activity, and changes in risk factors. Doctors reiterated the pelvic exam and specimen collections.
The women were also told to return for testing any time they had symptoms of vaginal discharge, itching, or odor. Doctors performed an exam and collected specimens at these visits as well. After the symptomatic visits, the men were also asked for new specimen collections. Thirty- three of the women developed at least one recurrent yeast infection within the year.
At the two-week and one-month visits, none of the women had symptoms of a yeast infection. But 20% had a positive culture for Candida in the vaginal area at the two-week visit and 29% tested positive for Candida after one month. The researchers found these women were no more likely to develop recurrent infections by the end of the one-year study period.
Among the men, nearly half tested positive for Candida species on the tongue and in the feces, while few shown Candida in their urine or semen. Researchers found no link between Candida in the men's specimens and Candida at the women's vulva, rectum, or tongue. They also found no link between recurrent yeast infections and signs of Candida at any site in either the men or women.
When sexual activities were looked at, however, the researchers found that women who had recurrences were more likely to have participated in cunnilingus (oral sex given to the woman) or masturbation of the woman with saliva in the past month. Only 14.5% of women reported masturbation with saliva, however, while 69% reported cunnilingus, suggesting oral sex is the more common risk.
Oral sex and masturbation with saliva proved to be risk factors which men showed signs of yeast in their mouths or not. The risk was also not affected by the presence of Candida in the women's genital area.
"We're not saying that oral sex is a problem for everyone, but if a woman is experiencing recurrence yeast infections, those activities put her at an increased risk," Reed says.
Factors such as the woman's age at first intercourse, lifetime number of partners, frequency of intercourse, and anal intercourse in the previous month were not associated with recurrences.
The research suggests that Candida exists in some women in balance with the other organizations and immune components in the vaginal area and that washing area with saliva may disrupt the balance, leading to symptoms of yeast infection.
Ultimately, from years of clinical experience, I conclude that in general, sex can increase yeast infections. This can occur for the reasons stated above. Candida can be transmitted orifice to orifice. Having sex will never cause Candida to be transmitted in the manner of someone with chronic fatigue, systemic Candida, or chronic Candida. It will occur only as a localized infection.
However, the sexual act can temporarily excite or spike hormones and their activity. This may lead to increased hormone activity, stimulating the growth of Candida. It is also possible that repeated oral sex with and infected partner can allow Candida to enter the digestive tract. If the recipient has a lowered immune response, low hydrochloric acid production in the stomach, or an existing imbalance in the intestines, it is possible that over time Candida infections may spread.
So absolutely, we must consider the individual case and the health and sexual practices of the partners in order to draw a conclusion.