Smallpox - Causes

Smallpox was a relatively contagious disease. The virus could be transferred from one person to another in a number of ways. A person could catch the virus by touching the lesions of an infected person. The virus could also be transferred in droplets of moisture produced during coughing or sneezing. And a person could get the virus from books, blankets, utensils, or other objects used by someone with the disease.

The virus usually entered the body through the respiratory (breathing) tract. It then passed through an incubation period of twelve to fourteen days. An incubation period is the time that passes after a person is infected before symptoms appear. During this time, the virus was multiplying within the body and moving through the bloodstream.