For women who have a high risk of contracting a sexually transmitted disease, their risk of developing bacterial vaginosis and the associated changes in vaginal microflora is reduced if they use condoms during every sexual encounter, according to a report in the journal Epidemiology.

Bacterial vaginosis is caused by an imbalance of the bacteria normally found in a woman’s vagina, referred to as vaginal microflora, which is upset by an overgrowth of bacteria not usually present. It is the most common vaginal infection in women of child-bearing age. Symptoms include discharge, odor, pain, itching and burning.

Although any woman can get bacterial vaginosis, some activities or behaviors can upset the normal balance of bacteria in the vagina and put women at increased risk. These include having a new sex partner or multiple sex partners and using an intrauterine device (IUD) for contraception.

It remains unclear how effective condoms are at reducing bacterial sexually transmitted infections, explain Dr. Roberta B. Ness and colleagues from the University of Pittsburgh, Pennsylvania. They therefore investigated condom use, bacterial vaginosis and the growth of vaginal microorganisms associated with bacterial vaginosis in 871 women at high risk for sexually transmitted diseases.

Overall, women who consistently used condoms (10/10 sex acts) had a 45-percent decreased risk of bacterial vaginosis compared with women who did not use condoms, the authors report.

For women at an intermediate stage of bacterial imbalance, consistent condom use had even more protective effects (63 percent risk reduction),” the researchers found.

The study findings “lend some support to the theory that bacterial vaginosis is sexually transmitted, and provides a further rationale for recommending that women use condoms to reduce the risk of bacterial vaginosis,” the investigators conclude.

SOURCE: Epidemiology, November 2007.