6. Prevalence, genotype diversity and determinants of anal HPV infection in high-risk men attending a sexually transmitted infection clinic in Puerto Rico
Background Recent studies in Puerto Rico (PR) have reported an increasing incidence of anal cancer in Puerto Rican men. The objective of this study was to determine the prevalence, genotype distribution and risk factors associated with anal HPV infection among heterosexual men and men who have sex with men (MSM) attending an STI clinic in PR. Methods: We conducted a cross-sectional study of men 18 years and older. A comprehensive survey was administered that included a demographic and behavioural assessment. Logistic regression was performed to determine factors associated with any, high-risk (HR), low-risk (LR) and multiple anal HPV infection. Results: The mean age of the study sample was 38.0 ± 13.5 and 37.7 ± 13.0 years for MSM and heterosexual men, respectively. A third (29.8%) of the study sample reported being MSM. Significant differences were observed in the prevalence of any anal HPV infection for MSM (84.5%) as compared with heterosexual men (45.7%; P < 0.001). Although MSM showed a higher prevalence of both HR and LR HPV types, no significant differences were observed in the bivariate analysis. Overall, HR anal HPV infection was found in 58.5% of the participants. The most common HR types were 53, 58, 68, 51 and 31. Multiple HPV types in the anal canal were found in 50.0% of the sample. Multivariate logistic regression analysis showed that being a MSM was associated with any anal HPV infection (OR = 6.2; 95% CI 1.5, 25.7). Conclusions: Anal HPV is common among sexually active men attending this STI clinic, with a higher likelihood of any anal HPV infection among MSM.