MicrobeWorld

Smallpox (variola) is declared officially eliminated, the last naturally occurring case having been seen in 1977 in Somalia. Small quantities remain held under tightly controlled conditions in the U.S. and former U.S.S.R. Smallpox is the only microbial disease to ever have been deliberately eradicated.

More Information:

Victory Over Variola, ASM News 44, 1978. p. 639 [pdf]