Epidemiology of human papillomavirus infection

Anogenital human papillomavirus (HPV) infection is a sexually transmitted d isease (STD) that typically follows a self-limiting transient course for bo th sexes. The HPV incidences and prevalences vary greatly, because they ref lect the sexual activity of the individuals studied and of the population t hey are in contact with. Higher prevalences are seen in young, sexually act ive groups and in high-risk areas for cervical and penile cancer, e.g. in C olombia. There has also been an increasing trend with time in Western Europ e, paralleling the spread of other STDs and changes in sexual behavior. Pen ile intraepithelial neoplasia is usually positive for high-risk HPV DNA, mo stly of type 16, whereas only approximate to 50% of invasive penile cancers are positive for HPV DNA. This is similar to the role of high-risk HPV in vulvar carcinoma, where the attributable proportion is also approximate to 40-50%. Moreover, in both sites similar histologic types of squamous cell c arcinoma, i.e. the basoloid and basaloid/warty types, an mainly associated with high-risk HPV types. The studies performed so far have indicated that HPV has an etiological role in penile cancer, although the attributable pro portion may be only approximate to 40-50%.