Sequential acquisition of human papillomavirus infection between genital and oral anatomic sites in males.

Oral human papillomavirus (HPV) is associated with increasing rates of HPV-associated oropharyngeal cancer (OPC) in men. Sequential infection from one site to another has been demonstrated at the cervix and anus. Thus, risk of an oral HPV infection after a genital infection of the same type in the HPV infection in men study was investigated. Samples from 3140 men enrolled in a longitudinal cohort were assessed for sequential genital to oral infection with one of nine HPV types (HPV 6, 11, 16, 18, 31, 33, 45, 52 and 58); and then also sequential, same-type oral to genital infection. Incidence rate ratios (IRRs) compared rates of oral HPV among men with and without prior genital infection of the same type. Risk of sequential HPV infections were assessed using Cox proportional hazards model. Incidence of an oral HPV infection was significantly higher among men with a prior genital infection of the same type for any of the 9 HPV types (IRR: 2.3; 95% CI: 1.7-3.0). Hazard ratio of a sequential genital to oral HPV infection was 2.3 (95% CI: 1.7-3.1) and 3.5 (95% CI: 1.9-6.4) for oral to genital infection. Both changed minimally after adjustment for age, country, circumcision, alcohol use, lifetime sexual partners and recent oral sex partners. HPV infections at one site could elevate risk of a subsequent genital or oral HPV infection of the same type in men, emphasizing the importance of vaccination to prevent all HPV infections.