Abstract
OBJECTIVE: Describe the natural history of anal HPV among men. MATERIALS AND METHODS: Prospective study among men 18-70 years (n=665), from Cuernavaca, Mexico who completed questionnaires and provided specimens (HPV genotyped) at enrollment and 1+ follow-up visit. HPV prevalence and incidence were estimated. Prevalence ratios were calculated with Poisson regression using robust variance estimation. Person-time for incident HPV infection was estimated using number of events modeled as Poisson variable for total person-months. RESULTS: Anal infection prevalence: any HPV type=15%, high-risk=8.4%, HPV16=1.4%, tetravalent vaccine types (4vHPV)=4.4%, nonavalent vaccine types (9vHPV)=6.3%. Factors associated with prevalence: 50+ lifetime female sex partners (adjusted prevalence ratio, a PR=3.25, 95% CI:1.12- 9.47), 10+ lifetime male sex partners (aPR=3.06, 95%CI:1.4- 6.68), and 1+ recent male anal sex partners (aPR=2.28, 95%CI:1.15-4.5). Anal incidence rate: high-risk HPV=7.8/1000 person-months (95%CI:6.0-10.1), HPV16=1.8/1000 personmonths (95%CI:1.1-2.9),4vHPV=3.4/1000 person-months (95%CI:2.3-4.9) and 9vHPV=5.5/1000 person-months (95%CI:4.1-7.5). CONCLUSIONS: Implementation of universal HPV vaccination programs, including men, is a public health priority.