Background Oral human papillomavirus (HPV) infection increases the risk of a sub-set of head and neck cancers. The epidemiology of oral HPV infection is not well understood.

Aim To describe the prevalence and risk factors for oral HPV infection amongst STI clinic attendees.

Methods Participants were recruited from a STI clinic, completed a risk factor questionnaire and provided oral samples for HPV DNA testing by a highly sensitive PCR using the SPF-10 broad spectrum primers. Overall positivity (prevalence) for any HPV was calculated. Chi-square test was used to determine the association between risk factors and oral HPV-positivity.

Results Ninety-eight participants (50 men and 48 women) with a median age of 29 (range 20–52 years) were recruited. Overall, 67.4% (66 of 98) participants were positive. All participants reported a history of oral sex. Participants from a non-White ethnic group were more likely to be oral HPV-positive than Whites (63.1% vs. 92.9%, p = 0.03) and those who engaged in open mouth/deep kissing in the last 24 h were also more likely to be oral HPV-positive than those who did not (86.2% vs. 59.7%, p = 0.01). No statistically significant associations were found with recent history of oral sex, smoking, alcohol and cannabis use, or lifetime number of sexual partners.

Conclusion Oral HPV infection is common among STI clinic attendees. It is unclear whether these are transient oral HPV infections or true persistent infections with oncogenic potential. Our limited data suggest that recent open mouth/deep kissing behaviour is associated with transmission of oral HPV.