To discuss any illness, it is important to define it first. While some viruses appear and leave soon, others stay for a while, causing too many troubles. So-called variola virus belongs to the second category. It results into the disease called smallpox. It is easy to detect the disease visually as the pus appears on the body’s surface. It looks like the ugly lumps filled with the white liquid. These blisters expand during the course of illness.