Casualties from Anthrax Attack Could Be Reduced by Half if U.S. Develops Quick Response Plan Say Yale School of Management, Stanford, and M.I.T. Experts

March 17, 2003 – New Haven, CT – On the eve of war in Iraq, Yale School of Management expert Edward H. Kaplan, along with colleagues Lawrence M. Wein, Stanford University Graduate School of Business, and David L. Craft, M.I.T. Operations Research Center, predict the number of casualties from an aerosolized anthrax weapon dispersed into a crowded city could be reduced by half if antibiotics were distributed either pre-attack or within several hours post-attack.

The new study published in the online version of Proceedings of the National Academy of Sciences (PNAS) states that despite the heightened risk of such an attack taking place in the United States, authorities have yet to fully prepare for the casualties that may result or to develop a systematic response plan.

Kaplan, the William N. and Marie A. Beach Professor of Management Sciences at the Yale School of Management and Professor of Public Health at the Yale School of Medicine, and his colleagues developed a mathematical model that analyzes the destructive capacity of an aerosolized anthrax weapon dispersed into an urban center. The model helps researchers study how changing a number of parameters affects the extent of casualties from an anthrax attack. By varying a number of factors, such as geographic dispersion of aerosolized spores, the dynamics of anthrax disease progression, and the timing and organization of medical intervention, the researchers were able to predict which methods would be most effective in saving lives.

According to Kaplan, "It's one thing to simply worry about what anthrax can do to us, but quite another to determine how we can best respond to an anthrax attack. The United States must act quickly to put a rapid response plan in place. To not prepare for the possibility of such an attack puts many more lives at risk."

In the base case, where all exposed victims receive antibiotics after a 48 hour delay regardless of symptoms, more than 123,000 casualties are expected. However, the scientists estimate this number could be reduced by half if antibiotics were distributed either pre-attack or within several hours post-attack.

More lives can be saved if people take their medications properly and if medical care capacity could greatly increase (for example, mobile medical units and nationwide medical volunteers). The use of biosensors to rapidly detect an attack, or prioritizing victims by age or degree of illness can help, but perhaps surprisingly only slightly if antibiotics are disseminated very quickly.

This same team of researchers authored a widely-reported study modeling emergency response to a smallpox attack. This study (PNAS, August 6, 2002) was influential in changing the Bush Administration's smallpox response plan. As with their previous work on smallpox, Kaplan emphasizes that using a model to predict casualties as a function of emergency response logistics is crucial to prepare the government, the medical system and the public for an anthrax attack.