Dr. Hillier: In our experience, women who are treated with oral or intravaginal metronidazole have a much more rapid return of normal vaginal flora than women treated with clindamycin. Clindamycin has activity against Lactobacillus, so that in the week or two following therapy, women have very low levels of lactobacilli in the vagina.10
Dr. Ledger: I think these agents help cut down on the numbers of bacteria, which is certainly a better environment for reestablishing normal flora.
Dr. Faro: The problem with antibiotics is that they are broad-spectrum agents. They aren’t guns with a bullet directed at a certain bacterium or even a certain group of bacteria. They affect all bacteria. This is why we have such poor results.
Dr. Ledger: I think we need something more specific, but to get it we’re going to have to acquire more information on lactobacilli. On the other hand, postmenopausal patients with absent lactobacilli and no BV cast doubt in my mind that the lack of lactobacilli is the sole cause of BV.
Studies have shown that vaginal antifungal cream may markedly reduce the number of good lactobacilli in women who use them.
Dr. Faro: I’ve seen patients whose counts run around 10 to 4 or 10 to 5, yet they have healthy floras. I think the reason is that the Lactobacillus species they have are very potent producers of bacteriocin and hydrogen peroxide. In addition, we have found some ladies with strains or biotypes of Gardnerella who get recurrent BV and some who never have had the infection. So we end up dealing with a dual problem. We have a shift in the environment and we’re nurturing an organism that’s unaffected by the biodefense mechanisms that Lactobacillus produces. It’s very complex because we’re trying to change the environment of an ecological system to make it more conducive to the growth of Lactobacillus.
OBG Management: Since we know that lactobacilli excrete the natural disinfectant hydrogen peroxide to help maintain a healthy and normal balance of microorganisms in the vagina, is there an agent or a way to recolonize the vagina with it?
Dr. Hillier: In order for Lactobacillus to colonize the vagina it is necessary for the organism to attach to the vaginal epithelial cells. We are currently conducting trials to evaluate the value of recolonization therapy using a human-derived strain of a peroxide-producing Lactobacillus. In our study, women with BV were treated with metronidazole and randomized to receive capsules containing either 108Lactobacillus crispatus or placebo. The results are promising.
Dr. Ledger: There are other factors to consider since some women do not have a vaginal environment conducive to the health of lactobacilli. In fact, Guaschino showed that postmenopausal women not receiving HRT achieved a lactobacilli-dominated vaginal flora with exogenous estrogen therapy.
OBG Management: A recent survey noted that 30% of women thought it was acceptable to self-medicate symptoms of vaginal infections with home remedies. What are your thoughts?
Dr. Faro: Patients who self-diagnose and self-medicate often misdiagnose and medicate with the wrong agent.
Dr. Ledger: That’s right. In fact, Onderdonk, a premier clinical microbiologist at Harvard Medical School, looked at the impact of 1 vaginal antifungal cream and demonstrated that it markedly reduced the number of good lactobacilli in women who used it.11 It could be that some of these women who are self-medicating with over-the-counter antifungals may be altering their vaginal flora and doing more harm than good by creating an abnormal bacterial environment.
The male ejaculate may alter the vaginal microflora because it is usually very alkaline and has some immunologic-suppressing activities.
Dr. Faro: Absolutely. There are agents such as clotrimazole and tioconazole that have antibacterial activity that may alter their flora.12,13
OBG Management: How do you manage a patient with recurrent BV?
Dr. Hillier: There are no clear guidelines at present based on large, randomized, placebo-controlled trials showing that any specific regimen is effective for management of women with recurrent BV. Based on a small, randomized treatment trial presented by Sobel at the second international BV meeting, it was suggested that use of intravaginal metronidazole therapy for 10 days followed by twice-weekly intravaginal metronidazole for 3 months effectively suppressed the recurrence of BV in most women.14 Since this is a well-tolerated regimen that presents a practical approach, we currently employ this strategy. Larger randomized trials evaluating this strategy are ongoing.
Dr. Ledger: I have never been a big fan of giving antibiotics to the male partner in women with recurrent BV. One of the things that I do with recurrent BV patients is have the male use a condom. While there is no scientific evidence, I find that these women do not experience as many recurrences. The male ejaculate can alter the vaginal microflora because it is usually very alkaline. Also, the male ejaculate does have some immunological-suppressing activities. Sperm are foreign antigens that may inhibit the mechanisms that help control the growth of bacteria in the vagina. This may be what is affecting the overgrowth in some women