[Historical perspective of smallpox in Mexico: emergence, elimination, and risk of reemergence due to bioterrorism].

Smallpox has been considered a disease of historical interest. However, given the 2001 terrorist events in the U.S. with intentional release of spores of Bacillus anthracis, and the current political worldwide agenda, the risk of bioterrorism has become a global public health concern. The risk of an intentional release of Variola virus as a biological weapon mandates a critical review of the historical impact of the disease in our country and the possible risk of its intentional reemergence. Smallpox was introduced into susceptible Indian populations in the Americas in the 16th century, contributing to the collapse of the Aztec Empire. Francisco Xavier Balmis start a vaccination campaign in the New World, and his efforts are considered the first eradication campaign of vaccine preventable diseases. Due to his efforts, smallpox was eliminated in Mexico in 1951. In the posteradication era, there is small but finite risk of intentional release of Variola virus. In response to this risk, Mexico has developed a comprehensive National preparedness plan. The impact of a new epidemic of smallpox will be considered a catastrophic event from both a historical and public health perspectives.