A vaginal yeast infection, or vulvovaginal candidiasis, is a common fungal overgrowth caused by an overgrowth of Candida, typically Candida albicans. This yeast naturally lives in the body and is usually controlled by healthy bacteria in the vaginal microbiome. When this delicate balance is upset, the fungus multiplies rapidly, causing irritation, discharge, and discomfort. Most women will experience this condition at least once in their lifetime.
The Role of Sexual Transmission
Although a yeast infection is not classified as a sexually transmitted infection (STI), transmission during sexual activity is possible. It is not an STI because it is primarily caused by an imbalance in the body’s natural flora. However, sexual contact provides a direct pathway for the fungus to be exchanged between partners.
A male partner can carry Candida without showing symptoms and pass it to a female partner during intercourse. The physical act of sex can introduce a high concentration of the fungus into the vaginal environment, which can establish a new infection.
Recurrent infections in a female partner may indicate the male partner is a source of re-infection, creating a “ping-pong infection” cycle. Treating both partners simultaneously is often recommended in cases of persistent candidiasis to break this cycle of transmission.
Common Non-Sexual Causes of Infection
Most yeast infections result from changes within the woman’s body that disrupt the vaginal environment, rather than sexual transmission. The most frequent trigger is the use of broad-spectrum antibiotics. These medications kill off healthy bacteria, such as Lactobacillus, which normally control the yeast population, allowing Candida to multiply.
Hormonal changes also increase susceptibility to candidiasis. Pregnancy, oral contraceptive pills, or hormone therapy that raises estrogen levels create a favorable environment for yeast growth. Additionally, women with uncontrolled diabetes face a greater risk because high blood sugar levels promote fungal growth.
Certain environmental and hygiene practices can upset the vaginal pH balance. These factors create the warm, moist environment where yeast thrives:
- Excessive use of scented hygiene products, harsh soaps, or douching.
- Wearing tight, non-breathable synthetic clothing.
- Staying in wet clothes, such as a swimsuit, for too long.
Recognizing Male Candidiasis
Candida can cause an infection in men, known as penile candidiasis or balanitis, which is inflammation of the head of the penis. When symptomatic, it presents with a patchy, red, and itchy rash on the head of the penis or under the foreskin. Other signs include a burning sensation, small sores or blisters, and sometimes a thick, white discharge.
Men who are uncircumcised are at a higher risk because the space beneath the foreskin provides a warm, moist environment for fungal growth. Crucially, a man can be an asymptomatic carrier of Candida, meaning he may carry the fungus without visible symptoms. This makes it difficult to pinpoint him as the source of a recurrent infection.
Treatment and Prevention Strategies
Treatment for vaginal candidiasis involves antifungal medications. These are available as over-the-counter creams, ointments, or suppositories inserted into the vagina. A doctor can also prescribe a single-dose oral antifungal tablet, such as fluconazole. Symptoms usually clear up within a few days, but the full course of medication must be completed to ensure the infection is fully eradicated.
If a male partner shows symptoms of balanitis, he should be treated with a topical antifungal cream for seven to fourteen days. When a couple experiences recurrent infections, both partners should be evaluated and treated simultaneously to prevent the continuous passing of the fungus.
Prevention involves simple changes to reduce the risk of future overgrowth:
- Wearing breathable cotton underwear.
- Changing out of wet clothing quickly to keep the area dry.
- Avoiding douching and scented feminine hygiene products to maintain the vaginal microbiome balance.
- Maintaining tight blood sugar control for individuals with diabetes.