False-colour transmission electron micrograph (TEM) of Human Papillomaviruses (HPV) extracted from a plantar wart. Belonging to the papovavirus group, these DNA viruses appear spherical with surface capsomers clearly seen. HPV infections are transmitted by direct contact. In the case of plantar warts occurring on the soles of the feet, virus particles have been found on contaminated bathroom floors and towels, communal showers and around swimming pools. Plantar warts (verrucas), common and flat warts are most common in children; the lower incidence in adults may be an acquired immunity. Magnification: x17,150 at 6x7cm size.