12 The presence of these has been positively associated with being white, aged over 20 years, using barrier contraception, and low frequency of BV and gonorrhoea. The main hydrogen peroxide producing strains of lactobacilli (LB+) are L crispatus and L jensenii. Reduction in lactobacilli and hydrogen peroxide production But which of these happens first, and which is the most important? If we knew the answers to these questions, we could use this knowledge to try to prevent further recurrences of BV.

It is associated with a reduction in lactobacilli (LB) and hydrogen peroxide production, a rise in the vaginal pH, and the overgrowth of BV associated organisms (see fig 1). The exact mechanism for the onset of BV remains a mystery. These findings support the theory of relapse.

Some asymptomatic women considered themselves cured after treatment, but they continued to have significant abnormalities of vaginal flora, the more severe the abnormality the earlier the recurrence. Women who developed early recurrence tended to complain of an abnormal discharge at the end of therapy. Anaerobic Gram negative rods were isolated from 19% of the women post-therapy compared with 3% of the control group. Following treatment, raised vaginal pH was present in 65%, positive amine whiff test in 15%, and abnormal Gram stained flora in 24%. Complete clinical and microscopic cure occurred in only 23% of the episodes, in 61% there was an improvement, but in 16% there was clinical failure. 1 There were 31 episodes of BV during the study period and each was treated with metronidazole 500 mg twice daily for 7 days. Cook et al studied 13 women with recurrent BV over a 9 month period, and compared them with a control group of 31 women with no current, or history of, BV. 11 These findings do not support the theory of sexual transmission and re-infection.Ī study looking at risk factors for repeated episodes of BV suggests they are due to relapse. Five out of six trials, using oral metronidazole, tinidazole, or clindamycin to treat the male partner showed no benefit for the women. Yet treatment of the sexual partner demonstrates no benefit in terms of recurrence rates in women. 7, 10 These findings lead onto the next question about aetiology.Īre frequent episodes of BV the result of re-infection or relapse? If it is re-infection what are the pathogens and is it related to behaviour of the women or her sexual partner? If it is relapse what triggers the disruption in the flora? The link with sexual behaviour suggests that BV is sexually transmitted and that further episodes are due to re-infection. The increase in BV in women with new sexual partners was independent of frequency of intercourse, suggesting exposure to a new partner is a more important risk factor than the number of episodes of intercourse. Many papers have linked BV with sexual behaviour a recent change of sexual partner, 7 and multiple partners compared with one partner 10 increasing the risk. 9 The studies on douching and IUD use were longitudinal studies of incidence, so women with recurrent BV may benefit from stopping douching, and changing their method of contraception if they have an IUD. Several factors are known to increase the risk of BV, including younger age, 5 black ethnicity, 6 douching, 7 smoking, 8 and the IUD as contraception. 4 So following successful treatment, half of women will stay cured for years. Most relapses were during the first year and were significantly correlated with new sexual contacts. 3 In a study of long term follow up of women who had been successfully treated for BV, 48% remained BV free, and 52% had at least one further episode. Treatment trials report cure rates of 80–90% at 1 week, but recurrence rates of 15–30% within 3 months. 1, 2Ī search was performed using Dialog DataStar for articles published between 1966 and September 2003, using the keywords bacterial vaginosis, recurrent bacterial vaginosis, vaginal pH, vaginal lactobacilli, probiotics, and bacteriotherapy. There is no universally accepted definition of recurrent bacterial vaginosis, but in the few publications on the topic the definition used is three or more proved (clinically by Amsel’s criteria or microscopically) episodes of BV in 12 months. There is also a change in vaginal flora from the normal lactobacilli (LB) dominant to flora with greatly reduced numbers of LB and an overgrowth of Gardnerella vaginalis, Mycoplasma hominis, and anaerobic bacteria such as peptostretococci, Prevotella spp, and Mobiluncus spp. Bacterial vaginosis is characterised by a thin homogeneous white discharge, a vaginal pH of greater than 4.5, a positive amine test, and the presence of clue cells microscopically.

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