Molluscum contagiosum (MC) is a viral infection of the skin or occasionally of the mucous membranes, sometimes called water warts. It is caused by a DNA poxvirus called the molluscum contagiosum virus (MCV). MCV has no nonhuman-animal reservoir (infecting primarily humans, though equids can rarely be infected). The virus that causes molluscum contagiosum is spread from person to person by touching the affected skin. The virus may also be spread by touching a surface with the virus on it, such as a towel, clothing, or toys.