Penises not required: a systematic review of the potential for human papillomavirus horizontal transmission that is non-sexual or does not include penile penetration

The primary mode of human papillomavirus (HPV) transmission is through penetrative sex; however, there is evidence of other modes of transmission. No systematic review was found that focussed on HPV horizontal transmission that is not penocentric. A systematic review of the literature by searching Medline (Ovid), PubMed (NLM) and Embase (Ovid) was conducted to retrieve articles published from 1946 to March 2014. Studies that suggested evidence of nonsexual or non-penetrative sexual transmission of alpha-HPV genotypes were included. After review of 2061 titles and abstracts, 51 studies were abstracted. Fifteen studies examined HPV fomites from medical settings or public environments, and 36 examined HPV in humans. Human papillomavirus DNA was detected in the genital tract of female virgins, with prevalence estimates ranging from 0% to 51.1%. HPV transmission from hands to genitals or genitals to hands was reported for both sexes and heterosexual couples. Other studies commonly found HPV on surfaces in medical settings and public environments. Further studies on non-sexual and non-penetrative sexual transmission are needed to understand the complexity of HPV transmission. Health-care policies may need to be reassessed/established to ensure the safety of medical instruments and to reduce the risk of HPV nosocomial infection.