Smallpox

Abstract

Smallpox, otherwise known as variola, was first described in ancient Chinese texts dating from the eleventh century B.C. The Chinese were the first to discover that purposeful inoculation of lesional material into the nose of the un infected was preventative of disease in the sixth century B.C. (1). Although the disease was officially eradicated in 1979, known stocks of the material have been maintained in biolabs located in Russia and the United States, where they pose a potential source of public health concern if subverted as biowarfare agents (2–5). Smallpox belongs to the Poxvirus group of double-stranded DNA containing viruses that includes vaccinia, molluscum contagiosum, and cowpox. The poxviruses are among the largest of all human viruses, attaining a maximum diameter of 300 nm, and possess characteristic rectangular or cylindrical outer capsids and a central DNA core (6).