Bacterial Vaginosis (BV) is one of the most common vaginal conditions, resulting from an imbalance in the naturally occurring bacteria. It is defined by the overgrowth of anaerobic organisms, such as Gardnerella vaginalis, which replace the protective Lactobacillus species. Men cannot develop bacterial vaginosis because they lack the necessary vaginal anatomy. However, men can carry the specific bacteria associated with the condition on their genital surfaces and within their urethra.
Vaginosis vs. Pathogen Carriage
BV is fundamentally an ecological shift in the vaginal microbiome, not a standard infection caused by a single pathogen. The healthy environment is maintained by Lactobacillus bacteria, which produce lactic acid to keep the pH low. When this balance is disrupted, species like Gardnerella vaginalis, Prevotella, and Atopobium vaginae multiply, leading to the BV syndrome.
The male genital tract hosts its own collection of bacteria but lacks the delicate ecosystem required for the BV syndrome to develop. While men cannot get the condition of vaginosis, they can be colonized by the associated anaerobic bacteria on their mucosal surfaces. These organisms, particularly Gardnerella vaginalis, have been detected in the male urethra, on the coronal sulcus, and in semen samples. This colonization establishes a reservoir of the bacteria, often found in men who are sexual partners of women with BV.
Clinical Manifestations in Men
When BV-associated bacteria colonize the male genital tract, the most common outcome is asymptomatic carriage. The majority of men who harbor these organisms do not experience noticeable health issues. This is a sharp contrast to the pronounced symptoms women often experience, such as a strong odor and thin, gray discharge.
In some cases, the presence of these bacteria may be associated with non-specific, mild inflammation. One potential manifestation is non-gonococcal urethritis (NGU), which involves inflammation of the urethra. NGU symptoms can include a subtle penile discharge, a burning sensation during urination, or an itchy feeling.
Another potential manifestation is balanitis, which is inflammation of the head of the penis. These symptoms are often subtle or mistakenly attributed to other causes. Research findings regarding the direct link between BV-associated bacteria and these specific clinical syndromes in men remain inconsistent.
Transmission and Partner Implications
The primary clinical relevance of male carriage of BV-associated bacteria lies in its role in the transmission cycle and the persistence of the condition in female partners. Transmission of these organisms occurs primarily through sexual activity, as indicated by the higher prevalence of carriage in men who have female sexual partners. The bacteria can be exchanged between partners, establishing a reservoir in the male genital tract.
This carriage is strongly linked to the high rate of recurrent BV in women following antibiotic treatment. When a woman is treated for BV, the organisms are cleared from her vagina, but if her male partner remains colonized, re-exposure during sex can reintroduce the bacteria, causing the condition to return. Studies have shown that treating both the woman and her regular male partner concurrently can significantly reduce the likelihood of recurrence in the woman.
This evidence suggests that while men do not develop the condition themselves, their status as carriers is a public health concern for their partners. Consistent use of barrier methods, such as condoms, may help prevent the exchange of these bacteria. If a female partner experiences frequent or recurring BV, it is important for the couple to consult a healthcare professional to discuss the possibility of male partner treatment, even though current standard guidelines may not universally recommend it.