The purpose of this page is to disseminate information to Indiana University personnel and students about the history and some of the more technical information relating to bioterrorism and biological warfare with particular emphasis on anthrax.
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Endospores of Bacillus anthracis. The spores are green and the mother cells surrounding them are red. The configuration of the spores is lined up in "a string of pearls". (See arrow on figure above.) This is characteristic of Bacillus anthracis.
In addition to the information found below, more information on this topic can be found at the following sites: |
Background Information - To the best of our knowledge, bioterrorism and biowarfare started during the period of colonization of the Americas. During the French and Indian war, British and colonials would often dispatch an entire native tribe through a "peace offering" of a small pox-laced blanket. There was another delivery system suggested in the British Parliament during our revolutionary war: arrows that had been tipped with small pox could be used against George Washington's revolutionary army. But it was nearly two centuries later that the terror of biological warfare became a grim reality. During World War II the cause of anthrax, Bacillus anthracis,was perfected as an agent of human destruction. In a race against time the British/American team was the first to develop a delivery system for anthrax. This "bombule" or "bomblet" that was developed at Crane Naval Air Station in Southern Indiana in 1941 was tested on Guinard island off the coast of Scotland in 1942. All of the experimental sheep died within 72 hours and all of the other sheep on the island died shortly thereafter. In the 1950s the military secretly tested a microbe called Serratiaon several major US cities to learn more about air drops and movement inside of subway systems. They didn't do their home work; Serratia causes pneumonias occasionally and with the concentration that they were using one would expect civilian casualties. None of this operation was made public until declassification some two decades later. During the Nixon era, offensive biowarfare research was curtailed, and international treaties were signed to halt development and stockpiling of new biological weapons.
Up until the present, defensive research has often camouflaged the development of new and more deadly agents under the guise of something acceptable like vaccine research. But still, at least with defensive research, stockpiling of the agents is not permitted under present modifications of the 1972 treaty. Most countries except for blatant offenders like Iraq and North Korea comply at least to some degree with the basic treaty guidelines. In current international talks the US is trying to get inspection and enforcement added to the 1972 treaty. The US contends that countries like Iran, Syria and Libya probably have aggressive biowarfare programs, but site inspection is crucial to a successful disarmament. The recent biological warfare talks in Geneva have a much greater chance at success weighing the present international concern over the most recent bioterrorism crisis in the US. Considering the panic that only a "tiny bit of powder" has created among the American public, the global community must act quickly to stop the threat of "Blackmail" and other forms of bioterrorism. Public fear and ultimately panic arise out of a lack of basic knowledge about this subject. The following information and links to other web sites are designed to inform an academic readership about the basic underlying principles of biological weaponry and some of the details most often asked about the infectious agents themselves.
Top bioterrorism agents - Government experts dealing with bioterrorism
have come up with a list of the most likely candidates that might be used in
possible future attacks. This list includes:
1) Bacillus anthracis,the cause of anthrax
2) Brucellaspecies, the cause of undulant fever
3) Francisella tularensis,the cause of tularemia or rabbit fever
4) Yersinia pestis,the cause of plague or black death
5) Variola virus, the cause of small pox
6) Vaccinia virus chimeras (mythical monsters composed of several animal parts),
the cause of small pox and/or serious toxic diseases derived from other infectious
agents.
Why anthrax? Out of all of the potential biowarfare agents, B. anthracis is the easiest to grow and is the most environmentally stable. The other agents range from mildly difficult to grow to very difficult to grow. Moreover, once taken out of their protective container they are readily destroyed by moisture and atmospheric oxygen over a period of hours to a few days. On the other hand, when B. anthracisis used as a tactical weapon the land becomes uninhabitable for centuries even possibly millennia because of the longevity of the spores in the soil. When used as a bioterrorist agent the question of conquest is usually not an issue.
All of the above agents except the small pox virus can be obtained from natural sources if terrorists are knowledgeable and determined. Furthermore, agents as lethal or worse than the above are also endemic or naturalized in this country. Certain limitations of potential bioterrorists will usually protect us from these microbes. Knowledge of how to isolate them from nature and grow them takes considerable sophistication and training if the terrorist is not to be his own first victim. More over, knowledge of how to weaponize various agents is in most countries a closely guarded secret, if in fact the procedure has already been worked out. There are several procedures we must consider in order to weaponize or to turn an infectious agent into a tactical weapon. Each agent will have its own procedures. One of the most simplistic examples is anthrax. Here is a microbe with a big reputation, but because of its growth properties in culture it is considered by trained microbiologists as a fairly safe organism to work with, comparatively speaking. The spores stick together in culture and must be separated from each other in order to be small enough to enter the alveoli or air sacs of the lungs. Next the spores are electrically charged and tend to stick to surfaces that are oppositely charged, much like the attraction of opposite poles of a magnet. This characteristic prevents them in an other way from reaching their pulmonary target. To keep the spores on target they are electrically neutralized with a chemical. To further weaponize this agent traits such as antibiotic resistance may be engineered as well. The end product is a preparation of spores that float in the breeze and will easily penetrate dust masks. And when they have finally come to rest in dust or dirt, over and over again they can be re-born in air currents to cause pulmonary anthrax. Fortunately, there are a defined number of spores that it takes on an average to cause disease. This average is called the ID50 or infectious dose. For weaponized agents the LD50 or average lethal dose is often very close to the ID50. Still, as one moves away from the primary source of the agent the number of propagules, in this case, spores, decrease in number exponentially. What may be an LD50 at ground zero moves to a noninfectious dose for most people even 10 feet away(in still air).
Contrary to the anthrax bacillus which is not normally infectious or spread to others, the non-spore forming biowarfare agents, which are more delicate, depend on both primary and secondary sources of inoculation. In heavily populated areas the rate of secondary spread from primary infected individuals can be horrifying. However, as is the case with most biological agents, secondary spread is via an aerosol of respiratory droplets. These droplets can be filtered out in large part by ordinary dust masks. Another note on the upside is that the vaccines for some of the non-spore forming agents can act soon enough to prevent death after exposure.
As indicated above, more information on this topic can be found at the following sites: