Factors Related to Bacterial Vaginosis That Persists or Occurs Again after Treatment in Women Who Have Sex with Women

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The summary below is from the full report titled "Relationship of Specific Vaginal Bacteria and Bacterial Vaginosis Treatment Failure in Women Who Have Sex with Women." It is in the 1 July 2008 issue of Annals of Internal Medicine (volume 149, pages 20-28). The authors are J.M. Marrazzo, K.K. Thomas, T.L. Fiedler, K. Ringwood, and D.N. Fredricks.

What is the problem and what is known about it so far?

Bacterial vaginosis is a condition caused by the overgrowth of bacteria that normally live in the vagina. Women with bacterial vaginosis often have no symptoms, but some women have vaginal discharge, odor, or itching. Pregnant women with bacterial vaginosis are more likely than women without the condition to have babies who are premature or have low birthweight. Doctors can test for the condition by swabbing the vagina during pelvic examination and sending the swabs to the laboratory. To treat bacterial vaginosis, a woman takes an antibiotic either by mouth or by a gel inserted into the vagina. Unfortunately, bacterial vaginosis frequently persists or occurs again after treatment. It would be helpful if doctors could predict which patients are at high risk for persistent or recurrent bacterial vaginosis. Recently, studies have identified several types of bacteria associated with bacterial vaginosis. It is possible that certain types of bacteria are linked to a high risk for vaginosis that persists or recurs after treatment.

Why did the researchers do this particular study?

To find out whether specific types of bacteria or patient factors are related to bacterial vaginosis that persists or recurs after treatment.

Who was studied?

335 women 16 to 29 years of age who reported having sex with at least 1 other woman during the past year. They studied women who had sex with women because bacterial vaginosis is even more common in this group than in women who only have sex with men.

How was the study done?

The researchers tested all of the women for bacterial vaginosis and for the specific types of bacteria. Women with bacterial vaginosis received treatment with an antibiotic gel inserted into the vagina nightly for 5 nights. One month after treatment was completed, the researchers tested the women again for bacterial vaginosis. They also asked the women about health and sexual behaviors over the previous month. The researchers then compared the bacteria types and behaviors of women who did and did not test positive for bacterial vaginosis 1 month after treatment.

What did the researchers find?

Of the 335 women, 131 had bacterial vaginosis on the first test. Of these 131 women, 120 returned for repeated testing 1 month after treatment and a little more than one quarter tested positive again, showing that they had persistent or recurrent vaginosis. Women who tested positive for specific bacteria types before treatment and did not take all of the medication were more likely to have bacterial vaginosis on follow-up testing than those who had other bacteria types and took all of the medication. The researchers did not find specific sexual behaviors that were related to persistent or recurrent vaginosis.

What were the limitations of the study?

The study may have been too small to be able to find sexual behaviors that were related to persistent or recurrent infection. The results might not apply to women who only have sex with men.

What are the implications of the study?

Testing for specific bacteria when testing for bacterial vaginosis might help doctors to predict which women are at high risk for persistent or recurrent vaginosis.