Recent concerns over terrorism have focused attention on the possibility of harmful biological agents spreading through human mechanisms. For instance, the recent anthrax scare resulted from the distribution of anthrax through the U.S. mail. Experts have also speculated on the possible effects of distributing biological agents through air travel or by contaminating the water supply. Unfortunately, the possibility of distributing pathogens through the infrastructure of civilization is only part of the problem. Another option for the bio-terrorist is to introduce harmful biological agents through the distribution systems of the natural world.

Pathogens often spread by contact with a host species that acts as a carrier. For instance, certain bird species acted as carriers for the West Nile Virus, which spread quickly through the eastern and midwestern United States in 1999. The diverse and de-centralized structure of a biological ecosystem makes an attack through a natural system far more difficult to control or predict than an attack through the U.S. mail. For instance, the Yersinia pestis bacterium—the pathogen associated with bubonic plague— is transmitted through the bite of a flea. The flea is transported through the environment by a rodent. In the United States, prairie dogs and ground squirrels are often associated with the distribution of plague. The progression of a plague epidemic is therefore influenced by a complex range of factors, from the suitability of the environment for replication of the bacterium to the size and behavior of the prarie dog population where the agent is unleashed. When all these factors are considered, natural systems are  an extremely effective means for spreading disease, and a thorough study of potential carriers and distribution systems is essential for a full understanding of the bio-terrorist threat.

Previous bio-terrorism studies have focused on a relatively short list of well known agents (anthrax, botulism, Ebola, smallpox, tularemia) with simple, human distribution systems. The actual list of potentially harmful agents is much longer if you allow for the possibility of natural distribution. BRC’s Biological Terrorism Risk Assessment will study several potentially harmful pathogens that have received comparatively less attention. The study will use BRC’s DesktopGARP to model the effects of these agents on human health, agriculture, and natural resources.

In addition to identifying agents and modeling distribution scenarios, the Biological Terrorism Risk Assessment will:

• Investigate techniques for determining whether a disease outbreak is the result of a terrorist attack;

• Propose strategies for early detection of potential biological agents within the environment.

The Biological Terrorism Risk Assessment will lead to a better understanding of the bio-terrorist threat and better procedures for detecting and preventing possible attacks.