Human papillomavirus (HPV) DNA has been detected in vaginal samples from adolescent girls who report no previous sex and, in high-income settings, from fingertips, raising the possibility of non-sexual transmission. No such studies originate from East Africa which bears among the highest cervical cancer incidence and HPV prevalence worldwide. HPV-related oral cancer incidence is increasing, but oral HPV prevalence data from East Africa are limited. We aimed to describe the HPV DNA prevalence in genital and non-genital sites and in the bathroom of unvaccinated adolescent girls, and examine genotype concordance between sites.
We nested a cross-sectional study of HPV in genital and extragenital sites within a cohort study of vaginal HPV acquisition. Unvaccinated girls age 16–18 years in Tanzania, who reported ever having had sex, were consented, enrolled and tested for the presence of HPV DNA in vaginal samples collected using self-administered swabs, oral samples collected using an oral rinse, and on fingertips and bathroom surfaces collected using a cytobrush.
Overall, 65 girls were enrolled and 23 (35%, 95% CI 23% to 47%) had detectable vaginal HPV. Adequate (β-globin positive) samples were collected from 36 girls’ fingertips and HPV was detected in 7 (19%, 95% CI 6% to 33%). 63 girls provided adequate oral samples, 4 (6%, 95% CI 0% to 13%) of which had HPV DNA detected. In bathroom samples from 58 girls, 4 (7%, 95% CI 0% to 14%) had detectable HPV DNA. Of the 11 girls with extragenital HPV, six had the same genotype in >1 site.
We found a high prevalence of HPV in non-genital sites in adolescent girls and in their bathrooms, in this region with a high cervical cancer incidence. Concordance of genotypes between sites supports the possibility of autoinoculation.