Prevalence and Risk Factors of Human Papillomavirus Infection among Japanese Female People: A Nationwide Epidemiological Survey by Self-Sampling

BACKGROUND: Nationwide epidemiological surveys of behavioral factors and human papillomavirus (HPV) infection among Japanese women are scarce. This study aimed to determine the prevalence, genotype distribution, and significant predictive factors of HPV infection using self-collected vaginal samples from Japanese female people. METHODS: The study population consisted of 1,050 female subjects aged 16–75 years (median 30 years). The participants were asked to provide self-collected samples from the vaginal wall using cotton swabs for genotyping of HPV. We compared the participants’ characteristics and detected HPV genotypes to determine significant predictors of HPV infection. RESULTS: After excluding 47 participants (34 participants of unknown age, 11 virgin participants, 1 participant who engaged in sex with another woman, and 1 participant who did not undergo β-globin detection), 1,003 participants were included in the analysis. Of the 1,003 participants, 426 (42.5%) participants had at least one HPV genotype, 282 (28.1%) participants had high-risk HPV genotypes, 306 (30.5%) had low-risk HPV genotypes, and 162 (16.2%) participants had both HPV genotypes. HPV-16/18 positivity was found in 5.4% (54/1,003) participants. The most frequently detected high-risk HPV genotype was HPV-52 (86/1,003; 8.6% participants). The number of lifetime sex partners (≥6) and a present history of sexually transmitted infection (STI) were significant predictors of high-risk HPV infection. The number of lifetime sex partners (≥6), age of coitarche (≥20 years of age), unmarried status, and a present history of STI were significant predictors of low-risk HPV infection. CONCLUSIONS: The prevalence of high-risk and low-risk HPV infection among Japanese female subjects was 28.1% and 30.5%, respectively. The number of lifetime sex partners (≥6) and present history of sexually transmitted infection were the common significant predictors of high-risk and low-risk HPV infection.