Bioterrorism

Bioterrorism is terrorism by intentional release or dissemination of biological agents (bacteria, viruses or toxins); these may be in a naturally-occurring or in a human-modified form.

Definition
According to the U.S. Centers for Disease Control and Prevention (CDC) 1:

A bioterrorism attack is the deliberate release of viruses, bacteria, or other germs (agents) used to cause illness or death in people, animals, or plants. These agents are typically found in nature, but it is possible that they could be changed to increase their ability to cause disease, make them resistant to current medicines, or to increase their ability to be spread into the environment. Biological agents can be spread through the air, through water, or in food. Terrorists may use biological agents because they can be extremely difficult to detect and do not cause illness for several hours to several days. Some bioterrorism agents, like the smallpox virus, can be spread from person to person and some, like anthrax, cannot.

History
Biological terrorism dates as far back as ancient Roman civilization, where dead and rotting animals were thrown into wells to poison water supplies (Bock, 2001.) This early version of biological terrorism was used to destroy enemy forces covertly. It continued on into the 14th century where the bubonic plague was used to infiltrate enemy cities, both by instilling the fear of infection in residences, in hopes that they would evacuate, and also to destroy defending forces that would not yield to the attack. The use of disease as a weapon in this stage of history exhibited a lack of control aggressors had over their own biological weapons. Primitive medical technology provided limited means of protection for the aggressor and a battle's surrounding geographical regions. After the battle was won, the inability to contain enemies who escaped death led to widespread epidemics affecting not only the enemy forces, but also surrounding regions' inhabitants. Due to the use of these biological weapons, and the apparent lack of medical advancement necessary to defend surrounding regions from them, widespread epidemics such as the bubonic plague quickly moved across all of Western Europe, destroying a large portion of its population. The victims of biological terrorism in fact became weapons themselves. This was noted in the Middle Ages, but medical advancements had not progressed far enough to prevent the consequences of a weapons use (Eitzen and Takafuji, 1997).

In the 15th century, smallpox was used on contaminated clothing to defeat South American and Native American forces (Bock, 2001). Again, the use of biological weapons, for which limited protection and containment was available, led to casualties on both sides of battles. Bioterrorism continued to be an effective method of weakening an adversary but it was also difficult to contain. In the Revolutionary War, colonists were vaccinated from the smallpox virus and then used the virus to intentionally infect enemies. This demonstrated a major advancement in the evolution of bioterrorism. Once the ability to defend from biological warfare became possible through medical advancement, the weapons became far more valuable.

As time continued the use of biological warfare became more and more sophisticated. Countries were developing weapons that delivered much higher effectiveness and less chance of infecting the wrong party. One significant enhancement in biological weapon development was the first use of anthrax. Anthrax effectiveness was initially limited to victims of large dosages. This became a weapon of choice because it is easily transferred, has a high mortality rate, and could be easily obtained. Also, variants of the anthrax bacterium can be found all around the world making it the biological weapon of choice in the early 19th century. Another property of anthrax that helped fuel its use as a biological weapon is its poor ability to spread far beyond the targeted population.

By the time World War I began, attempts to use anthrax were directed at animal populations. This was ineffective. Instead, the use of poisonous mustard gas became the biological weapon of choice. The sheer horror of its affects lead to a treaty called the Geneva Protocol of 1925. The treaty was created to prevent the use of asphyxiating gas as a method of biological warfare (Brooks, 2001). While this was a significant advancement toward the prevention of biological weapon use, the treaty said nothing about weapon development. Secretly, biological weapon development programs existed in many nations. While no documented instances of biological weapon use exist it is believed that this was primarily due to the programs immaturity and not the unwillingness to use them.

American biological weapon development began in 1942. President Franklin D. Roosevelt placed George W. Merck in charge of the effort to create a development program. These programs continued until 1969, when by executive order President Richard Nixon shut down all programs related to American offensive use of biological weapons (http://fas.org/nuke/guide/usa/cbw/bw.html).

Accusations of the use of biological weapons against North Korea were spread during Vietnam, however it is believed that those accusations were propaganda developed by the North Korean regime to villainize American Armed Forces. As the 1970s passed, global efforts to prevent the development of biological weapons and their use were widespread. In 1972 the prohibition of development, production and stockpiling biological weapons was developed.

In the 1980’s Iraq made substantial efforts to develop and stockpile large amounts of biological weapons. By the end of the 80’s Iraq had several sites dedicated to the research and development of biological warfare. They began to test their findings in the late 80’s. These actions lead to the first Gulf war in which Iraq’s biological weapons were dismantled and destroyed.

Since that time, efforts to use biological warfare has been more apparent in small radical organizations attempting to create fear in the eyes of large groups. Some efforts have been partially effective in creating fear, due to the lack of visibility associated with modern biological weapon use by small organizations. In 1995 a small terrorist group launched a terrorist attack aboard a Tokyo subway. The attack killed twelve and affected more than 5000. The response of Japanese emergency services successfully prevented an outcome with much higher mortality rates.

In the United States a more recent biological terrorism attack occurred in 2001 when letters laced with infectious anthrax were delivered to news media offices and the U.S Congress (Johnston, 2005). The letters killed 5. While many believed this attack to be in relation to Iraq’s development of biological weapons, tests on the anthrax strand used in the attack pointed to a domestic source.

Types of biological agents
The CDC has defined and categorized bioterrorism agents according to priority 2 as follows:

Category A agents
These are biological agents with both a high potential for adverse public health impact and that also have a serious potential for large-scale dissemination. Many of these agents require Biosafety Level 4 laboratories. The Category A agents are anthrax, smallpox, plague, botulism, tularemia, and viral hemorrhagic fevers.


 * Anthrax : Anthrax is a non-contagious disease. An anthrax vaccine does exist but requires many injections and has side effects that render it unsuitable for general use.


 * Smallpox : Smallpox is a highly contagious virus. It transmits easily through the atmosphere and has a high mortality rate (20-40%). Smallpox was eliminated in the world in the 1970s, thanks to a worldwide vaccination program. However, some virus samples are still available in Russian and American laboratories. Some believe that after the collapse of the Soviet Union, cultures of smallpox have become available in other countries. Although people born pre-1970 will have been vaccinated for smallpox under the WHO program, the effectiveness of vaccination is limited since the vaccine provides high level of immunity for only 3 to 5 years. As a biological weapon smallpox is dangerous because of the highly contagious nature of both the infected and their pox. Smallpox occurs only in humans, and has no external hosts or vectors.


 * Botulinum toxin : Botulinum toxin is one of the deadliest toxins known, and is produced by the bacterium Clostridium botulinum. Botulism causes death by respiratory failure and paralysis. It is not easy to obtain even though it is found in the cosmetic products Botox and Dysport.


 * Plague : Plague is a disease caused by the Yersinia pestis bacterium. Rodents are the normal host of plague, and the disease is transmitted to humans by flea bites and occasionally by aerosol in the form of pneumonic plague.  The disease has a history of use in biological warfare dating back many centuries, and is considered a threat due to its ease of culture and ability to remain in circulation among local rodents for a long period of time.


 * Viral hemorrhagic fever : This includes the Filoviridae (containing the Marburg and Ebola genera), and the Arenaviridae (for example Lassa or Machupo). Ebola has fatality rates ranging from 50-90%. No cure currently exists, although vaccines are in development.  The United States and the erstwhile Soviet Union both investigated the use of Ebola for biological warfare, and the Aum Shinrikyo group possessed cultures of the virus.  Ebola kills its victims through multiple organ failure and hypovolemic shock. Marburg was first discovered in Marburg, Germany.  Fatality rates range from 25-100%, and although a vaccine is in development, no treatments currently exist aside from supportive care. The Arenaviruses have a greatly reduced fatality rate, but a larger presence, chiefly in central Africa and South America. Many of the Arenaviruses can be aerosol transmitted, making them particularly viable for bioterrorism.


 * Tularemia : Tularemia, or rabbit fever, has a very low fatality rate if treated, but can severely incapacitate. The disease is caused by the Francisella tularensis bacterium. It has been widely produced for biological warfare due to its highly infective nature, and ease of aerosolization.

Category B agents
Category B agents are moderately easy to disseminate and have low mortality rates.
 * Brucellosis (Brucella species) Brucellosis is an infectious disease caused by the bacteria of the genus Brucella. These bacteria are primarily passed among animals, and they cause disease in many different vertebrates. Various Brucella species affect sheep, goats, cattle, deer, elk, pigs, dogs, and several other animals. Humans become infected by coming in contact with animals or animal products that are contaminated with these bacteria. In humans brucellosis can cause a range of symptoms that are similar to the flu and may include fever, sweats, headaches, back pains, and physical weakness. Severe infections of the central nervous systems or lining of the heart may occur. Brucellosis can also cause long-lasting or chronic symptoms that include recurrent fevers, joint pain, and fatigue
 * Epsilon toxin of Clostridium perfringens
 * Food safety threats (e.g., Salmonella species, E coli O157:H7, Shigella, Stash)
 * Glanders (Burkholderia mallei)
 * Melioidosis (Burkholderia pseudomallei)
 * Psittacosis (Chlamydia psittaci)
 * Q fever (Coxiella burnetii)
 * Ricin toxin from Ricinus communis (castor beans)
 * Staphylococcal enterotoxin B
 * Typhus (Rickettsia prowazekii)
 * Viral encephalitis (alphaviruses, e.g.: Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis)
 * Water supply threats (e.g., Vibrio cholerae, Cryptosporidium parvum)

Category C agents
Category C agents are pathogens that might be engineered for mass dissemination because they are easy to produce and have potential for high morbidity or mortality (examples: nipah virus, hantavirus and multi-drug resistant Tuberculosis (MTB).

1915-16 livestock sabotage by Germany
Dr Anton Dilger, a German-American physician, worked for Germany in the U.S. (Chevy Chase and Baltimore) in 1915 and 1916 with cultures of anthrax and glanders with the intention of biological sabotage on behalf of the German government. Other German agents are known to have undertaken similar sabotage efforts during WWI in Norway, Spain, Romania and Argentina.

1984 Rajneeshee Salmonella attack
In 1984, followers of the Bhagwan Shree Rajneesh attempted to control a local election by incapacitating the local population by infecting salad bars in eleven restaurants, doorknobs, produce in grocery stores and other public domains with Salmonella typhimurium in the city of The Dalles, Oregon. The attack caused about 751 people to get sick (no fatalities). This incident was the first known bioterrorist attack in the United States in the 20th century.

2001 anthrax attack
In September and October of 2001, several cases of anthrax broke out in the United States in the 2001 anthrax attacks, caused deliberately. This was a well-publicized act of bioterrorism. It motivated efforts to define biodefense and biosecurity, where more limited definitions of biosafety had focused on unintentional or accidental impacts of agricultural and medical technologies.

Planning for and reacting to a bioterrorist attack
Planning may involve the development of biological identification systems.

Until recently in the United States of America, most biological defense strategies have been geared to protecting soldiers on the battlefield rather than ordinary people in cities. Financial cutbacks have limited the tracking of disease outbreaks. Some outbreaks, such as food poisoning due to E. coli or Salmonella, could be of either natural or deliberate origin.

Preparedness and response to a biological attack
Biological agents are relatively easy to obtain by terrorists and are becoming more threatening in the U.S., and laboratories are working on advanced detection systems to provide early warning, identify contaminated areas and populations at risk, and to facilitate prompt treatment. Methods for predicting the use of biological agents in urban areas as well as assessing the area for the hazards associated with a biological attack are being established in major cities. In addition, forensic technologies are working on identifying biological agents, their geographical origins and/or their initial son. forts include decontamination technologies to restore facilities without causing additional environmental concerns (2).

Biosurveillance strategies
In 1999, the University of Pittsburgh's Center for Biomedical Informatics deployed the first automated bioterrorism detection system, called RODS (Real-Time Outbreak Disease Surveillance). RODS is designed to draw collect data from many data sources and use them to perform signal detection, that is, to detect the a possible bioterrorism event at the earliest possible moment. RODS, and other systems like it, collect data from sources including clinic data, laboratory data, and data from over-the-counter drug sales. In 2000, Michael Wagner, the codirector of the RODS laboratory, and Ron Aryel, a subcontractor, conceived of the idea of obtaining live data feeds from "non-traditional" (non-health-care) data sources. The RODS laboratory's first efforts eventually led to the establishment of the National Retail Data Monitor, a system which collects data from 20,000 retail locations nation-wide.

On February 5, 2002, George W. Bush visited the RODS laboratory and used it as a model for a $300 million spending proposal to equip all 50 states with biosurveillance systems. In a speech delivered at the nearby Masonic temple, Bush compared the RODS system to a modern "DEW" line (referring to the Cold War ballistic missile early warning system).

The principles and practices of biosurveillance, a new interdisciplinary science, were defined and described in the Handbook of Biosurveillance, edited by Michael Wagner, Andrew Moore and Ron Aryel, and published in 2006. Biosurveillance is the science of real-time disease outbreak detection. Its principles apply to both natural and man-made epidemics (bioterrorism).

Data which potentially could assist in early detection of a bioterrorism event include many categories of information. Health-related data such as that from hospital computer systems, clinical laboratories, electronic health record systems, medical examiner record-keeping systems, 911 call center computers, and veterinary medical record systems could be of help; researchers are also considering the utility of data generated by ranching and feedlot operations, food processors, drinking water systems, school attendance recording, and physiologic monitors, among others. Intuitively, one would expect systems which collect more than one type of data to be more useful than systems which collect only one type of information (such as single-purpose laboratory or 911 call-center based systems), and be less prone to false alarms, and this appears to be the case.

In Europe, disease surveillance is beginning to be organized on the continent-wide scale needed to track a biological emergency. The system not only monitors infected persons, but attempts to discern the origin of the outbreak.

Researchers are experimenting with devices to detect the existence of a threat:
 * tiny electronic chips that would contain living nerve cells to warn of the presence of bacterial toxins (identification of broad range toxins)
 * fiber-optic tubes lined with antibodies coupled to light-emitting molecules (identification of specific pathogens, such as anthrax, botulinum, ricin)

Limitations of bioterrorism
Bioterrorism is inherently limited as a warfare tactic because of the uncontrollable nature of the agent involved. A biological weapon is useful to a terrorist group mainly as a method of creating mass panic and disruption to a society. However, technologists such as Bill Joy have warned of the potential power which genetic engineering might place in the hands of future bio-terrorists ; a bacterial agent might be engineered for genetic or geographical selectivity. Such a scenario formed the plot of the science fiction novel The White Plague and the action novel Area 7.

Other forms of bioterrorism
The use of agents that do not cause harm to humans but disrupt the economy have been discussed. A highly relevant pathogen in this context is the foot-and-mouth disease (FMD) virus, which is capable of causing widespread economic damage and public concern (as witnessed in the 2001 and 2007 FMD outbreaks in the UK), whilst having almost no capacity to infect humans.

The genomic revolution requires scientists to follow a recognised Code of Conduct. The 'dual-use' technology dilemma implicates issues further; good scientific inventions can be reapplied along a sinister vector.