Molluscum contagiosum (MC) is caused by a virus called the molluscum contagiosum virus (MCV).
MCV belongs to a family of viruses known as poxviruses, which are particularly well adapted for infecting human skin cells. Smallpox, which was eradicated from the globe in the 1970s, is another member of the group.
How MCV is spread
MCV can be spread through:
- close direct contact, such as touching the skin of someone who is infected
- sexual contact – this does not necessarily involve full sexual intercourse; it can just be close physical contact
- sharing contaminated objects, such as towels, flannels, toys and clothes
Once you have been exposed to MCV and the skin infection appears, the virus can spread to other areas of your skin.
MCV is highly infectious. It is easily spread among young children at nursery and school who play together and share toys. It is not known exactly how long someone with MCV is contagious, but the contagious period is thought to last up until the last lesion completely heals.
However, most people are naturally resistant (immune) to MCV. This means that although they may come into contact with the virus, they will not develop MC.
People are more likely to be affected by MC if they have a weakened immune system. For example, if they are receiving chemotherapy treatment for cancer, or if they are HIV positive.
