Poxviruses are a family of viruses that cause a range of diseases in humans and animals, including smallpox and molluscum contagiosum. Smallpox is a highly contagious and often fatal disease caused by the variola virus, a member of the poxvirus family. It is characterized by fever, fatigue, and a distinctive rash. Molluscum contagiosum is a skin infection caused by a poxvirus and is characterized by small, firm, raised bumps on the skin. It is contagious and can spread through direct contact or contact with infected items.