Transmission of human papillomavirus (HPV) of the genus Alphapapillomavirus is unlikely to occur from hand-to-genital contact; the majority of infections are likely caused by genital-to-genital contact, according to research results published in The Lancet Infectious Diseases.
The relative significance of each mode of transmission was assessed using a prospective cohort study of female university students aged 18 to 24 years and their male sexual partners. Eligible participants had initiated sexual activity in the last 6 months. Women were examined at clinic visits at baseline and every 4 to 6 months for 24 months and males had a baseline visit and one follow-up visit 4 months later. Hand and genital swabs were tested via polymerase chain reaction (PCR) for DNA from 36 HPV types.
Results found 264 women and 291 men with valid hand samples. The hazard ratio (HR) of incidence detection of HPV in genital samples from women was 5.0 (95% CI, 1.5-16.4) when her partner’s hand sample tested positive for the same type vs negative; this was reduced to 0.5 (95% CI, 0.1-1.8) after adjusting for the partner’s genital HPV status. The same analysis in male participants found the HR of incidence of detection of HPV on men’s genitals was 17.4 (95% CI, 7.9-38.5) with a partner who had positive samples from the hand vs partners whose hand samples were negative; this dropped to 2.3 (95% CI, 0.9-6.2) after adjustment. After adjustments for hand status, the HR of type-specific incident detection of HPV in genital samples associated with partners’ genital positivity was 19.3 (95% CI, 11.8-31.8) in women and 28.4 (95% CI, 15.4-52.1) in men.
The data was limited in that there were very few observations from individuals exposed to a partner only positive for HPV in a hand sample in incident genital detection analyses. Further, few couples were not engaging in sexual intercourse, which limited the ability to completely rule out hand-to-genital transmission. The study investigators also cautioned that the results might not be generalizable to non-heterosexual couples.
While the results did not rule out hand-to-genital transmission, they do, however, “bolster the assertion that if hand-to-genital transmission occurs, this type of transmission is unlikely to be important in genital HPV infections in sexual partnerships.”
Researchers believe that transmission modes of HPV are important for shaping the public health advice surrounding HPV and as testing increases more women will become aware of their infections status so information regarding transmission should be available.
Malagón T, Louvanto K, Wissing M, et al. Hand-to-genital and genital-to-genital transmission of human papillomaviruses between male and female sexual partners (HITCH): a prospective cohort study. [published online February 8 2019]. Lancet Infect Dis. doi:10.1016/S1473-3099(18)30655-8