High-risk human papillomavirus in Galicia, Spain: prevalence and evaluation of the sample representativeness.

Background: The prevalence of high-risk genotypes of the human papillomavirus (HR-HPV) in Galicia remained unknown before the introduction of the HPV vaccine. The objective of this study was to estimate this prevalence in non-vaccinated women when vaccination against HR-HPV started. Sample representativeness was also evaluated.

Methods: Female volunteers aged 16-64 years, residents in Galicia, Spain, completed a questionnaire and provided biological samples for a virological study and for cytology. The sample was weighted; prevalence rates were estimated and are shown with 95% confidence intervals.

Results: Virological results were available for 1703 women. HR-HPV prevalence was 10.1%, decreasing notably at ages above 30 years. HPV-16 was the most frequent genotype and 3.6% of women were infected by more than one genotype. No adjustment was necessary to generalize the results of the study.

Conclusions: In Galicia in 2009 there would be 96 400 women aged 16-64 years infected with HR-HPV. It is possible to estimate HR-HPV prevalence in a population starting from a volunteer sample.