Biology of genital tract human papillomaviruses.

A large number of HPV types infect humans. They infect squamous epithelia of the skin and mucous membranes. Infections are widespread in sexually active populations. Some HPV types have oncogenic potential. Infections with HPV-16, HPV-18, and some additional types are risk factors for cervical cancer. The HPV-6 and HPV-11 types are responsible for most of the genital condylomas and nearly all respiratory papillomas. The immunologic responses to HPVs are not well understood.