Risk factors for human papillomavirus infection among women in Portugal: the CLEOPATRE Portugal Study

Objective: To investigate demographic, socioeconomic, lifestyle, and medical factors that might predispose women to cervical human papillomavirus (HPV) infection.

Method: A cross-sectional population-based study was performed. Women aged 18-64 years who attended selected obstetrics and gynecology or sexually transmitted disease (STD) clinics in mainland Portugal between February 2008 and March 2009 were recruited, according to an age-stratified sampling strategy. Liquid-based cytology samples were analyzed centrally for HPV genotype and for cytologic features. Univariate and multivariate logistic regression analyses identified risk factors for HPV infection.

Results: Among the 2326 women evaluated, the crude prevalence of HPV infection was 19.4%. Lifetime number of sexual partners was a strong predictor of HPV infection (odds ratio 5.44 for 5-10 partners versus 1 partner; P<0.001). Other risk factors were young age (particularly among women aged 20-24 years; P<0.001); country of birth other than mainland Portugal (P=0.002); education up to secondary school level (P=0.010); smoking history (≤ 10 years; P=0.004); and any STD in the past 12 months (P=0.052).

Conclusion: Data from the present study may aid identification of women at increased risk of HPV infection and target prevention strategies.

Trial registration: National Commission of Data Protection (CNPD) registration number 5346/2007; Sanofi Pasteur MSD study number HPV-E05.