About Bacterial Vaginosis

Bacterial vaginosis is one of the most common infections of the vagina. Bacterial vaginosis is caused by an imbalance between Lactobacilli (a “friendly” bacteria of the vagina) and other bacteria. The overgrowth of these other bacteria seems to cause bacterial vaginosis, but the exact cause is not completely understood. Additionally, no single type of bacteria causes bacterial vaginosis, which is considered a polymicrobial (many bacteria) infection. Bacterial vaginosis is not considered to be a sexually transmitted infection, but it is more common in women who are sexually active. Douching and smoking are both risk factors for bacterial vaginosis. Genetic factors and sexual activity may also play an important role.

The most common symptoms of bacterial vaginosis are: Abnormal vaginal discharge that is usually thin and gray or milky in color. Abnormal vaginal odor, often described as “fishy.” This odor may be especially noticeable after sexual intercourse or after urination. Mild vulvar irritation can be a symptom, but usually there is no external discomfort with bacterial vaginosis.

A diagnosis is made by evaluating vaginal discharge collected during a pelvic exam, checking the vaginal pH, looking for an abnormal odor, and examining the secretions under the microscope. Cultures may be collected during the exam and are used to rule out other infections that may cause abnormal vaginal discharge. Patients are notified if any of these cultures are positive and require treatment.

Bacterial vaginosis may resolve without treatment but should be treated if symptomatic. It is recommended that women undergoing a gynecological procedure or surgery be treated even if there are no symptoms present. Treatment is also considered if the patient is having other vulvar symptoms that may be aggravated by the presence of bacterial vaginosis.

Common treatments for bacterial vaginosis include: Oral medications: metronidazole, tinidazole. Vaginal medications: clindamycin vaginal cream, metronidazole vaginal gel; less commonly, metronidazole vaginal suppositories. Male sexual partners are not treated because current research has not shown any benefit to the female with bacterial vaginosis if her partner is treated. However, it may be helpful to treat female sexual partners.

Regular condom use significantly reduces the risk of getting bacterial vaginosis again and is strongly encouraged. We recommend no douching or smoking because these practices are risk factors for bacterial vaginosis.

Why does bacterial vaginosis recur after treatment? It is not known why some women have recurrences of bacterial vaginosis after they have completed treatment. In some cases, the abnormal bacteria persist after standard courses of treatment, or the normal Lactobacilli fail to re-establish themselves after treatment. If bacterial vaginosis recurs more than three times a year, a more prolonged course of therapy to resolve the symptoms is recommended. Follow-up may include a three- to six-month regimen of maintenance therapy to suppress the abnormal bacteria.