Before I go deeper into specific bioterror agents and biodefense policies and programs, I would like to start by defining the threat of bioterrorism.
According to W. Seth Carus from the National Defense University, bioterrorism is “the use, attempted use, or the credible threat to use a biological agent or a toxin by a non-state actor for the purpose of advancing a political, religious, or ideological cause.” Additionally, the CDC defines bioterrorism as “the deliberate release of viruses, bacteria, or other germs (agents) used to cause illness or death in people, animals, or plants.” Simply put, bioterrorism is the use of a biological agent as a weapon by terrorist groups.
The actual biological agents used in attacks can either be naturally-occurring or modified by humans. More primitive bioterrorists would most likely utilize a disease agent that could be isolated from nature and grown readily in a lab, whereas more advanced bioterrorists may be able to genetically alter an agent to increase its virulence, confer drug resistance, or make it more transmissible.
Agents can be disseminated in several ways, including through the air, through water, or through food. The method of dissemination depends on the biological characteristics of the agent, the capabilities of the terrorists, and the objective of the attack. No dissemination method is perfect, and all have their limitations, making it one of the biggest hurdles in any successful bioterror attack. Following dissemination, further spread of disease may occur via person-to-person transmission if the selected agent is capable of such infection.
The extent of the damage caused by a biological attack is dependent on several factors. It starts with the choice of agent and ends with the actual attack – everything from the purity of the preparation to weather conditions when dissemination occurs plays a role on the final outcome. This makes preparation for and response to an attack difficult, as there are numerous possibilities that authorities must consider.
So why would terrorists use a biological weapon? First of all, biological agents are relatively easy to obtain compared to chemical, radiological, or nuclear weapons. A big issue with biological weapons is the concept of “dual use”; that is, methods, processes, and equipment associated with legitimate biomedical laboratory research can also be used to conduct bioweapons research and development. This makes identifying offensive biological research extremely difficult.
Beyond this, biological agents have the potential to cause widespread damage. In addition to any illnesses and/or deaths that occur, a biological attack also has the ability to generate public fear and panic. Depending on the nature of the attack, the economy could struggle, the public health system could falter, and contamination could result in extensive property loss and damage. Though biological attacks may not result in mass destruction, mass disruption of normalcy in a country would almost definitely occur in the wake of a bioterror event.
Finally, biological agents disseminated by terrorists may appear identical to natural disease outbreaks. Cases may not be evident for hours or even days after initial release of the agent, providing terrorists with time to flee the affected area, notify media of the attack, or release more agent in other areas. Further, without cause to suspect an act of bioterrorism, authorities may overlook the possibility of an attack altogether. This could lead to difficulty treating the sick, spread of secondary infections, or a sudden influx of both sick and worried well patients.
The CDC has classified bioterrorism agents into three categories (A, B, C) based on how easily the agent can be spread and the severity of illness that the agent causes.
Category A agents pose the highest risk to the public and national security. These agents are characterized by high morbidity and mortality, ease of spread and transmission, potential for major public health impact, and requirement of special action for public health preparedness. The Category A agents are: Anthrax, Botulism, Plague, Smallpox, Tularemia, and Viral Hemorrhagic Fever.
Category B agents are the second highest priority because they are moderately easy to spread, result in moderate morbidity and low mortality, and require specific enhancements of the CDC’s laboratory capacity and enhanced disease monitoring. The Category B agents are: Brucellosis, Epsilon toxin of Clostridium perfringens, Food safety threats, Glanders, Melioidosis, Psittacosis, Q fever, Ricin toxin, Staphylococcal enterotoxin B, Typhus fever, Viral encephalitis, and water safety threats.
Category C agents are the third highest priority, and they include emerging pathogens that may be engineered for mass spread in the future. These agents are characterized by ease of availability, ease of production and spread, and potential for high morbidity and mortality with major health impact. Category C agents are all emerging infectious diseases, such as Nipah and Hendra viruses.
Though the threat of bioterrorism may be low compared to conventional terrorism, the consequences are disproportionately high. It is important that both policy makers and the public remain cognizant of the threat.
Over the next few weeks, I will be profiling the diseases listed in each of the three agent categories in an effort to help educate the public. More information on bioterrorism can be found here on the CDC’s website.
Tags: bioterrorism, cdc
