Papillomaviruses and polyomaviruses

Papillomaviruses and polyomaviruses are small, nonenveloped, double-stranded DNA viruses. There are over 100 human papillomavirus (HPV) types that infect epithelia of skin and mucous membranes. They infect only humans, and cause conditions including the following: Skin warts and verrucas—caused by types 1 and 2; infection initiated when, after e.g. minor skin abrasions, the basal cells of the epithelium come in contact with infectious virus....