Natural history of human papillomavirus infection among young men from Kisumu, Kenya

Human papillomavirus (HPV) infection is necessary for the development of invasive cervical cancer among women and is a risk factor of other anogenital cancers among women and men. Among men, data on the natural history of HPV infection and on risk factors of HPV-associated penile lesions are limited.An HPV-ancillary study, nested within a randomized controlled trial (RCT) of male circumcision, was conducted in Kisumu, Kenya from 2002-2007. All participants were human immunodeficiency virus seronegative, uncircumcised and aged 17-24 years at baseline. Penile exfoliated cell specimens were collected at baseline, 12 and 24-month visits from the glans/coronal sulcus and shaft of participating men and tested using GP5+/6+ polymerase chain reaction. An additional visual inspection exam with acetic acid was conducted at the 24-month visit to determine the presence of colposcopy-detected penile lesions.For incidence and persistence analyses, 949 participants enrolled in the control arm of the main RCT were included. Median follow-up time was 24.2 months (range 11.6-30.4). The incidence of any HPV infection was 24.3/1,000 person-months. A total of 18.3% (95% confidence interval [CI]: 15.0-22.3) of incident HPV infections in the glans persisted from the 12 to 24-month visits and 13.5% (95% CI: 11.1-16.3) of prevalent HPV infections in the glans persisted from baseline until at least the 12-month visit. HPV clearance was similar for high-risk versus low-risk infections and by age group.Of 267 men participating in visual inspection exams from both arms of the RCT, 143 were circumcised and 124 uncircumcised. Circumcised men had a lower prevalence of flat penile lesions (0.7%) versus uncircumcised men (26.0%) age-adjusted odds ratio (OR)=0.02 95% CI: 0.003-0.1. Men with flat lesions had increased odds of HPV DNA positivity and high HPV16/18/31 viral load compared to men without flat lesions.The natural history of HPV infection among men may be different than that previously described for women, with a relatively high incidence of penile HPV infection found among men. Differences in patterns of high and low-risk HPV clearance between men and women may also exist. This study suggests male circumcision reduces the prevalence of HPV-associated flat penile lesions and may reduce HPV transmission between sexual partners.