Bacterial Vaginosis (BV) is one of the most common causes of vaginal discharge, affecting up to 30% of women in the United States between the ages of 14 and 49. This condition involves an alteration of the delicate bacterial environment within the vagina, leading to uncomfortable symptoms. Given its high prevalence and connection to sexual activity, confusion exists regarding whether BV can be transmitted to a male partner. While BV is not classified as a traditional sexually transmitted infection (STI), its association with sex raises valid questions about transmission risk.
Understanding Bacterial Vaginosis
Bacterial Vaginosis is a condition defined by an imbalance in the vaginal microbiome, not by the introduction of a new, foreign pathogen. In a healthy vagina, protective bacteria, primarily Lactobacillus species, dominate and produce lactic acid, which maintains a low, acidic pH. This acidic environment naturally suppresses the growth of other microbes.
BV occurs when these beneficial Lactobacilli significantly decrease, allowing an overgrowth of various anaerobic bacteria, such as Gardnerella species and Prevotella species. This shift increases the vaginal pH, creating an environment where these non-protective bacteria thrive. The condition is therefore an endogenous infection—an overgrowth of organisms that are already present.
Because BV is an overgrowth of existing organisms, it is not classified as an STI, unlike infections caused by external agents like gonorrhea or chlamydia. However, factors like having new or multiple sexual partners, douching, and not using condoms increase the risk of developing BV.
Transmission and Male Partners
The direct answer to whether a man can “get” BV is no. Bacterial Vaginosis is specifically a diagnosis of an imbalance in the vaginal flora, an environment unique to those with a vagina. Men do not possess the biological environment necessary for the condition to manifest with its classic symptoms.
Despite this, the bacteria associated with BV, such as Gardnerella, can be present on the penis and inside the urethra of male partners. This is known as temporary carriage, where the bacteria exist without causing an infection or symptoms. Studies have detected these BV-associated bacteria in the male penile microbiome, especially in uncircumcised men.
Carriage of these bacteria in a male partner is typically asymptomatic, meaning they experience no discharge, odor, or discomfort. In very rare cases, the presence of these organisms may be associated with non-specific urethritis, an inflammation of the urethra. This condition involves symptoms like a burning sensation during urination or a mild penile discharge.
The carriage of BV-associated bacteria provides a mechanism for the microbes to be passed back to a female partner. This exchange during sex is believed to be a major factor contributing to the high rates of BV recurrence. The bacteria carried by the male partner may re-introduce the organisms that disrupt the female partner’s vaginal balance.
Managing BV in Relationships
The high rate of BV recurrence is a challenge, with over 50% of women experiencing a return of symptoms within 12 months after initial antibiotic treatment. This frequent recurrence has led researchers to investigate the role of sexual partners in reintroducing the bacteria, even though routine treatment for male partners is not standard practice.
Recent research, however, is starting to challenge this traditional approach, particularly for couples dealing with recurrent BV. A 2025 study found that treating the male partner alongside the female partner significantly reduced the rate of BV recurrence. In this trial, women whose male partners received a combination of oral and topical antibiotics had a recurrence rate of 35% within 12 weeks, compared to 63% in the group where only the woman was treated.
This finding suggests that treating the male partner may be a valuable strategy for women who experience chronic BV that repeatedly returns. The dual treatment regimen typically involves the man taking oral antibiotics and applying an antibiotic cream to the penis for seven days, synchronized with the female partner’s treatment.
Couples should use barrier methods, such as condoms, or abstain from sexual activity during the treatment period to prevent the immediate reintroduction of bacteria. Individuals experiencing recurrent BV should discuss this new evidence and the option of partner treatment with a healthcare provider.