ABSTRACT
Objective: Human papillomavirus (HPV) vaccination was introduced in Japan in April 2013, as a national immunization program for girls aged 12–16 years, after an initial introduction in 2010 as a public-aid program for girls aged 13–16 years. The Yuri-Honjo district had the highest vaccine coverage among women aged 17–51 years in 2017, due to the original public-aid program. The aim of this study was to evaluate the differences in the vaccine types of HPV16/18 infections between 2008–2012 (pre-vaccine era) and 2013–2017 (vaccine era).Materials and Methods: We evaluated whether HPV vaccination was associated with a decrease in the prevalence of HPV16/18 and high-risk HPV and the incidence of HPV-associated cervical lesions. A total of 1,342 women aged 18–49 years, covering both the pre-vaccine and vaccine eras, who visited Yuri Kumiai General Hospital and underwent HPV genotype tests from June 2008 to December 2017 were compared.Results: Among women aged 18–24 years with higher vaccine coverage (68.2%), the prevalence of HPV16/18 and high-risk HPV decreased from 36.7% and 69.4%, respectively, in the pre-vaccine era to 5.8% and 50.0%, respectively, in the vaccine era (p=0.00013 and p=0.047, respectively). Among those with cervical intraepithelial neoplasia grade 2− and grade 2+, HPV16/18 prevalence decreased from 30.0% to 2.7% (p=0.0018) and from 81.8% to 36.4% (p=0.030), respectively. In this age group, the rate of HPV16/18 positivity decreased significantly. Among age groups with lower vaccine coverage, HPV prevalence did not significantly differ between the two eras.Conclusion: The prevalence of HPV16/18 and high-risk HPV significantly decreased in women aged 18–24 years, most of whom were vaccinated. HPV vaccination effectively reduced the prevalence of HPV16/18 infections in the Yuri-Honjo district.
ABSTRACT
This study was conducted to clarify the benefits of using cervical cytological examinations and human papilloma virus (HPV) testing in our cervical cancer screening program, which was carried out during the period from April 2012 through March 2013 in the Yuri-Honjo district of Akita Prefecture. A total of 772 women underwent this screening. About 11.3% (87/772) of the examinees tested positive for HPV, and of these 87 women, 64 were also positive for HPV DNA in the examinations subsequently conducted in the outpatient clinic. Of the HPV DNA-positive women who showed no sign of abnormalities in cytology, 67.6% had lesions cervical intraepithelial neoplasia (CIN) 1 and above, and five women had l CIN 2/3. Compared with the conventional cytology which detected nine women with CIN 2/3, our screening method with a combination of cytology and HPV testing found 14 women with CIN 2 or 3. To upgrade the cervical cancer screening, we recommend HPV testing should be used in combination with cervical cytology.