Bacterial vaginosis is associated with uterine cervical human papillomavirus infection: a meta-analysis

Abstract

Background: Bacterial vaginosis (BV), an alteration of vaginal flora involving a decrease in Lactobacilli and predominance of anaerobic bacteria, is among the most common cause of vaginal complaints for women of childbearing age. It is well known that BV has an influence in acquisition of certain genital infections. However, association between BV and cervical human papillomavirus (HPV) infection has been inconsistent among studies. The objective of this meta-analysis of published studies is to clarify and summarize published literature on the extent to which BV is associated with cervical HPV infection.

Methods: Medline and Web of Science were systematically searched for eligible publications until December 2009. Articles were selected based on inclusion and exclusion criteria. After testing heterogeneity of studies, meta-analysis was performed using random effect model.

Results: Twelve eligible studies were selected to review the association between BV and HPV, including a total of 6,372 women. The pooled prevalence of BV was 32%. The overall estimated odds ratio (OR) showed a positive association between BV and cervical HPV infection (OR, 1.43; 95% confidence interval, 1.11-1.84).

Conclusion: This meta-analysis of available literature resulted in a positive association between BV and uterine cervical HPV infection.

Figure 1

Flow-chart of article selection for inclusion in meta-analysis BV - HPV.

Figure 2

Forest plot of estimates of association between bacterial vaginosis and cervical human papillomavirus infection. Studies are identified by references. Each study is represented by a black square and a horizontal line, which corresponds to the estimate (ES) and 95% confidence interval (CI) of odds ratios. Area of black squares reflects weight of study in the meta-analysis.

Figure 3

Funnel plot to assess publication bias. The full circles represent the 12 included study estimates of association between BV and prevalent cervical HPV infection. The size of association of each study is plotted on the horizontal axis, against the standard error on the vertical axis (on logarithmic scale). The vertical line in the funnel plot indicates the fixed-effects summary estimate, while the sloping lines indicate the expected 95% confidence intervals for a given standard error.

Figure 4

Cumulative meta-analysis to evaluate small-study effect. Studies are ordered according to descending variance on odds ratios. The vertical line indicates the no-association line (OR 1.0). Each study is represented by a horizontal line, corresponding to the OR (or estimates ES) and symmetric 95% CI.