Chapter 2: natural history of anogenital human papillomavirus infection and

This chapter suggests promising areas of future epidemio-logic research on human papillomavirus (HPV) and anogeni-tal cancer, organized around our understanding of cervical carcinogenesis. The major steps in cervical carcinogenesis include HPV infection, HPV persistence over a certain pe-riod of time, progression to precancer, and invasion. Back-ward steps include clearance of HPV infection and regres-sion of precancer. Additional studies of incident HPV infections among virgins initiating sexual activity could clarify the earliest aspects of transmission and immune re-sponse. Research on older women and their male partners should focus on understanding the determinants of varying age-specific HPV prevalence curves and underlying dynam-ics of viral persistence, clearance, and latency. It will be particularly important for epidemiologists to define HP