[Smallpox virus as biological weapon].

Smallpox, because of its high case-fatality rate, easy transmission from human to human, lack of specific treatment represents nowadays one of the main threats in bioterrorist attacks. Over the centuries, naturally occurring smallpox with its case-fatality over 30 percent and its ability to spread in any climate and season has been treated as the most dangerous infectious disease. But it is now, 25 years after the last documented case of smallpox and cessation of routine vaccination in present mobile and susceptible population, smallpox virus spread might be rapid and devastating.