Age-specific and genotype-specific carcinogenic human papillomavirus prevalence in a country with a high cervical cancer burden: results of a cross-sectional study in Estonia

OBJECTIVES: To describe age-specific and type-specific carcinogenic human papillomavirus (HPV) prevalence prior to large-scale effect of HPV vaccines in Estonia and to analyse the risk factors associated with carcinogenic HPV. DESIGN: Cross-sectional study using self-administered questionnaire and self-collected vaginal swabs for detection of HPV infection. SETTING: Estonian Biobank database. PARTICIPANTS: Stratified random sample of women aged 30–33, 57–60 and 67–70 years living in one of the three largest counties in Estonia. Of 3065 women approached, 1347 (43.9%) returned questionnaires and specimens for HPV DNA detection. OUTCOME MEASURES: HPV prevalence and fully adjusted ORs with 95% CIs for risk factors. RESULTS: HPV prevalence was highest among women aged 30–33 years (18.7%; 95% CI 15.8 to 21.9) followed by those aged 67–70 years (16.7%; 95% CI 12.4 to 22.0) and 57–60 years (10.2%; 95% CI 7.8 to 13.3). HPV16 and HPV56 were the most common among women aged 30–33 years (both 4.0%; 95% CI 2.7 to 5.9), and HPV68 was the most common among women aged 57–60 years (2.8%; 95% CI 1.5 to 4.7) and 67–70 years (6.4%; 95% CI 3.6 to 10.4). Vaccination with nonavalent vaccine would have halved the carcinogenic HPV prevalence among women aged 30–33 years. The odds of infection with carcinogenic HPV were higher among women with six or more sexual partners among younger (OR 2.99; 95% CI 1.54 to 5.81) and older (OR 3.80; 95% CI 1.25 to 11.55) women and lower (OR 0.35; 95% CI 0.17 to 0.72) among younger married women. CONCLUSIONS: This study demonstrated U-shaped age-specific genotype profile of carcinogenic HPV prevalence, indicating that public health providers should focus on developing exit strategies for the cervical cancer screening programme in Estonia with a possible extension of HPV testing beyond the current screening age of 65 years. Generalisability of the findings of this study may be affected by the low response rate.