Bacterial Vaginosis (BV) is a disorder of unknown etiology, characterized by a foul smelling vaginal discharge, loss or reduction of the normal vaginal Lactobacilli, and overgrowth of other anaerobic bacteria. Thus, it presents a formidable problem for clinicians as well as microbiologists researching its etiology, clinical course, treatment, and epidemiology. The present work focuses on the unresolved issues of the epidemiology and treatment of BV in order to provide valid methods for treatment studies of this condition and to describe the prevalence of BV in defined populations.

The first study validates the use of PAP-stained smears in the diagnosis of BV. The study assesses the methods of Amsel’s clinical criteria and Nugent criteria on Gram-stain smears, against Pap-stained smears and also validates different observers. The result shows that the PAP-staining of vaginal smears is a good method in BV diagnosis; the kappa value is 0.86 (interobserver weighted kappa index) compared to 0.81 for Gram-stained smears, and 0.70 for rehydrated air-dried smears using the mean Nugent score as the criterion standard. This enables population based studies on archived PAP-stained smears from the screening of cervical cancer.

In the second study, we use the knowledge gained from study one to investigate the prevalence of BV in a cohort from the population of Åland. The prevalences of BV on the Åland Islands were: 15.6 %, 11.9 %, 8.7 %, and 8.6% in 1993, 1998, 2003, and 2008, respectively. This means that the prevalence of BV decreased between1993-2008 from 15.6% to 8.6%. The confidence intervals are not overlapping, thus indicating a significant decrease in prevalence from 1993 to 2008.

The third study is a prospective, double-blind placebo controlled treatment study of BV. After conventional treatment with clindamycin, the patients were treated with adjuvant treatment of Lactobacilli-loaded tampons or placebo. The study showed no differences between the treatment and the placebo group, indicating that the tampon does not work at all. There are a variety of possible explanations for the result, which are analyzed in this thesis.

The fourth study aimed to evaluate whether clindamycin is retained for a long time in the vaginal mucosa, thus disturbing the Lactobacilli in an attempt to reimplant Lactobacilli in the probiotic treatment studies. In conventional treatment, it is also useful to know whether clindamycin is retained, especially when considering the pressure from antibiotics on the antimicrobial sensitivity pattern. In the study, we found that the clindamycin disappears rapidly.

Conclusion: BV research requires effort from many different scientific disciplines and the riddle of this condition and its treatment can only be resolved by concerted actions in research and treatment. The vision for the future includes, among other factors, better molecular biology based diagnostic tools, and knowledge of population based bacterial floras.