Richard Preston scared the heck out of me with, “The Hot Zone,” and coincidentally, introduced me to the fascinating world of microbiology and the the world of viruses. Naturally, I was quite enthusiastic to read his new latest non-fiction book titled, “Demon in the Freezer.” It was completely enthralling and again, he scared me to death and really made me think about the threat of biological warfare.

Preston starts with the anthrax attack on American Media in Boca Raton, then bounces back and forth between the 2001 anthrax attacks there and in Washington (and the deaths of postal workers who handled the letters) and the lurking threat of smallpox being used as a biological weapon.

Smallpox is one of the nastiest diseases to ever affect humans. Unlike many other diseases (such as influenza and ebola), smallpox only affects humans; any other reservoir species died off or the virus changed sufficiently that it can only live in humans. Because of the lack of a natural reservoir, the World Health Organization, with massive contributions from the U.S., the Soviet Union, and other countries, was able to eliminate it through a program of vaccination and encapsulation.

Officially, the smallpox virus only exists in two freezers, one in the United States, under the control of the National Centers for Disease Control (CDC) in Atlanta, Georgia, the other in a lab called Vector in the Russian Federation. But Preston presents stories about Soviet weaponization of smallpox for use in ballistic missiles, and strongly suggests that samples of the virus, along with biologists who had worked on the weaponization programs, have been sold or taken to various “axis of evil” countries such as Iraq, Iran, North Korea, and others.

My feeling is that the terrorist emphasis is a bit overblown, but Preston’s interviews with veterans of the WHO eradication program and scientists working with anthrax, smallpox, ebola, and other serious disease organisms at the CDC and U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID, the descendant of U.S. military biowarfare research) make the book.