Verrucas are caused by the human papilloma virus (HPV) and can be easily spread via contact with a contaminated surface or skin-to-skin contact. Verrucas are more likely to spread if the skin is damaged or wet, meaning swimming pools and communal showers and changing areas provide the perfect conditions to spread the virus.
People who have a weakened immune system, either through a medical condition or from taking immunosuppressant drugs, are more likely to develop verrucas.