The term natural disaster most often evokes images of earthquakes, hurricanes, and floods, but history offers evidence that disease can be the most deadly of disasters. When the Spanish flu pandemic of 1918–19 struck, infecting one-fifth of the world's population, the response techniques of public health officials in Europe and the United States could be traced back to the Middle Ages.

Social distancing through quarantines and suspension of public gatherings were primary tools in the battle against the spread of infection. These tools are still used in the 21st century, along with more sophisticated measures like vaccines, antiviral drugs, and a level of international cooperation unconceivable in earlier times. Despite advances in medicine and public health [Page 118]practices, however, the devastation wrought by uncontrolled infectious disease ...