Knowledge of HPV infection and vaccination among vaccinated and unvaccinated teenaged girls.

To assess the knowledge of teenaged girls on human papillomavirus (HPV) infection and vaccination 12 months after the start of a vaccine administration and information campaign.Between May 15 and June 15, 2009, an anonymous questionnaire was given to 629 girls attending a secondary school in a northeastern Italian city (286 were vaccinated against HPV, 343 were unvaccinated) to investigate their knowledge on HPV infection, transmission, prevention, vaccination, and post-vaccination behaviors. The responses were evaluated with respect to the vaccination status of the participants.Vaccinated teenaged girls had no more knowledge than unvaccinated ones about the route of HPV transmission, and the relationship between HPV and AIDS. Vaccinated girls had less knowledge than unvaccinated girls about preventing transmission by condom (P=0.003) and about the correlation between HPV and penile cancer (P=0.034) and warts (P=0.001). Furthermore, compared with unvaccinated girls, more vaccinated girls believed that contraceptive pills might prevent HPV-related disease (P=0.001). Vaccinated girls better understood the importance of performing regular Pap smears after vaccination (P=0.021).Knowledge on HPV infection and vaccination remains suboptimal, especially among vaccinated teenaged girls, despite a broad information campaign. Misconceptions about the utility of secondary prevention may increase risky sexual behaviors.