Bacterial vaginosis--a disturbed bacterial flora and treatment enigma

The syndrome bacterial vaginosis (BV) is characterized by a disturbed vaginal microflora in which the normally occurring lactobacilli yield quantitatively to an overgrowth of mainly anaerobic bacteria. As BV is a possible cause of obstetrics complications and gynaecological disease--as well as a nuisance to the affected women--there is a strong impetus to find a cure. In BV treatment studies, the diagnosis criteria for diagnosis of BV vary considerably and different methods are used for cure evaluation. The design of study protocols varies and there is no consensus respecting a suitable time for follow-up visits. For the purpose of this review, available data were recalculated for 4-week post treatment cure rates. For oral metronidazole the 4-week cure rate was found not to exceed 60-70%. Treatment regimens with topical clindamycin or topical metronidazole have the same cure rates. It can thus be said that no sound scientific basis exists for recommending any particular treatment. There is no evidence of beneficial effects on BV engendered by partner treatment, or by addition of probiotics or buffered gel. Long-term follow-up (longer than 4 weeks) shows a relapse rate of 70%. With a primary cure rate of 60-70%, and a similar relapse rate documented in the reviewed literature, clinicians simply do not have adequate data for determining treatment or designing clinical studies. This is unfortunate since--apart from the obvious patient benefits--clinical studies can often serve as a guide for more basic studies in the quest for underlying disease mechanisms. In the case of BV there is still a need for continued basic studies on the vaginal flora, local immunity to the flora and host-parasite interactions as an aid when designing informative clinical studies.