What is bioterrorism?

Definition

Bioterrorism, or biological terrorism, is the intentional release of bacteria or viruses into a civilian population to harm that population and, thereby, achieve a political or social end.

Biological Agents

Found in nature, biological agents threaten human populations when terrorists engineer these agents for release. The agents are cultivated to make them more resistant to medicines and vaccines and more easily transmitted in a population. The Centers for Disease Control and Prevention (CDC) in the United States classifies biological terror agents by their likelihood for use by terrorist groups and by their risk to a population. The CDC groups bioterrorism agents into categories A, B, and C.

Category A Agents

Cited as highest priority are category A agents, which are rare in the United States. These agents are easily transmitted and would cause a high death rate and would demand a proactive public health preparedness strategy. A agents include anthrax (Bacillus anthracis ), botulism (Clostridium botulinum toxin), plague (Yersinia pestis ), smallpox (Variola major ), tularemia (Francisella tularensis ), and viral hemorrhagic fever filoviruses, such as Ebola and Marburg, and arenaviruses, such as Lassa and Machupo.

Anthrax. An anthrax infection is triggered by B. anthracis, a bacterium
that forms spores, or dormant cells that reawaken under certain conditions. There
are three types of anthrax infection: those that involve the skin (cutaneous), the
lungs (inhalation), and the digestive tract (gastrointestinal). Anthrax does not
spread from person to person. People normally contract an anthrax infection by
handling or ingesting infected animal products. Symptoms can appear within seven
days. For cutaneous anthrax infection, symptoms include the appearance of
nonpainful skin blisters with a black area in the center. For gastrointestinal
anthrax, symptoms are nausea, loss of appetite, bloody diarrhea, fever, and
stomach pain. For inhalation anthrax, symptoms are similar to those of a common
cold: significant chest congestion and shortness of breath.

Botulism
. Spread by the bacterium C. botulinum, botulism is a muscle-paralyzing disease. It is not spread from person to person. People normally contract botulism from infected food or from an infected wound. Infants can contract the disease from the presence of the bacterium in their digestive tract. The food-borne form of botulism has a potential for becoming a public health emergency, as the toxin can contaminate large amounts of food. After ingesting the toxin, symptoms of double vision, dry mouth, slurred speech, and muscle weakness appear. Gradually, paralysis spreads throughout the body. Though most treated persons recover within weeks, untreated persons can die from paralysis of the breathing muscles.

Plague
. Caused by the Y. pestis bacterium, plague originates with rodents and their fleas. Though bubonic plague is transmitted through a rodent or flea bite, pneumonic plague can be transmitted through the air from person to person or through a deliberate aerosol release. Once exposed, a person experiences symptoms within one to six days that include cough, shortness of breath, chest pain, nausea, and abdominal pain. Plague is diagnosed through blood, sputum, or lymph-node aspirate sampling and is treated with antibiotics. Untreated, plague results in respiratory failure.

Smallpox
. The two forms of smallpox are V. major, which is severe and most common, and the less common and less deadly V. minor. The four types of V. major smallpox are ordinary, modified, flat, and hemorrhagic. Ordinary V. major, causing 90 percent of known cases, has a fatality rate of 30 percent, according to the CDC. The flat and hemorrhagic types are rare and usually fatal. Humans are the only known carriers of smallpox, and they spread the disease to others through close personal contact. Following an incubation period of seven to seventeen days, an infected person becomes contagious and experiences fever, head and body aches, and a rash of small red spots (first in the mouth and throat, then over the entire body). The last known case of smallpox in the United States was in 1949, and the last known case worldwide was in Somalia in 1977. The Variola virus exists only in science laboratories.

Tularemia
. Tularemiais caused by the bacterium F. tularensis, which is found in rodents and rabbits. A human contracts the disease upon being bitten by an infected tick or fly, by handling an infected carcass, by ingesting contaminated food or water, or by inhaling the airborne bacteria. Appearing within three to five days after exposure, symptoms include spiked fever, chills, headache, diarrhea, muscle aches, joint pain, dry cough, and weakness. Tularemia is treated with antibiotics.

Viral hemorrhagic fevers. Filovirus viral hemorrhagic fevers (VHFs), such as Ebola and Marburg, and arenavirus VHFs, such as
Lassa and Machupo, are known by the CDC as severe multisystem syndrome diseases.
VHFs attack multiple systems of the body, an attack accompanied by bleeding.
Persons experience symptoms of fever, achiness, and fatigue before seeing bleeding
under the skin and from the mouth, eyes, and ears. VHF may progress to nervous
system damage or kidney failure. Initially transmitted from contact with rodents
and their bodily excretions or by mosquito or tick bites, some VHFs (as Ebola,
Marburg, and Lassa) can spread through human-to-human contact. Though there is no
direct treatment for VHFs, the antiviral drug ribavirin is sometimes administered
to persons with a VHF disease.

Category B Agents

Ranked by the CDC as second highest priority, category B agents are moderately
easy to transmit and result in lower mortality rates. B agents include
brucellosis (Brucella
species); epsilon toxin of Clostridium perfringens
; food safety threats (Salmonella
, Escherichia coli
, and Shigella
); glanders (Burkholderia mallei
); melioidosis (B. pseudomallei); psittacosis (Chlamydophila psittaci
); Q fever (Coxiella burnetii
); ricin toxin from Ricinus communis
(castor beans); staphylococcal enterotoxin B; typhus fever (Rickettsia prowazekii
); viral encephalitis Alphaviruses, such as Venezuelan equine encephalitis,
eastern equine
encephalitis, and western equine encephalitis; and
water-safety threats, such as Vibrio cholerae
and Cryptosporidium parvum
.

Category C Agents

The agents with the third highest priority are those in category C; they
include emerging pathogens. Newly discovered diseases such as nipah virus and hantavirus infections are in category C and are rated according to
availability, ease of production, and potential for causing death.

History of Biological Weapons

At the end of the nineteenth century, scientists discovered a link between microorganisms and the outbreak of illness. They began to understand how diseases are spread through air, food, and water supplies, person-to-person contact, and insect bites. Upon uncovering these facts, scientists rapidly found ways to protect people against the outbreak of several diseases.

By the early twentieth century, some Western governments began to explore the harvesting and use of biological agents for use as weapons. In World War I, Germany undertook the first-known state-sponsored biological weapons program, deliberately infecting the horses and mules of enemy forces. In the 1920s, the French conducted research in biological weapon aerosols, increasing research in the mid-1930s.

In 1942, American biologists Theodor Rosebury and Elvin A. Kabot noted that B. anthracis, in its dormant-spore state, can easily be used as a biological weapon. The spores can withstand disbursement in hot or cold environments. Viewing this pathogen as a potential threat, Rosebury and Kabot recommended the development of an anthrax vaccine. They also described how plague bacillus, if freeze-dried, could also be weaponized in an aerosol. As a result of Rosebury and Kabot’s findings on the potential for use of biological weapons, Allied soldiers were administered antibiotics and vaccines during World War II.

The September 11, 2001, terrorist attacks in the United States prompted a surge in support and funding for defense against bioterror threats. This support and funding led to the development of technologies for detecting airborne threats and for treatment of disease caused by bioterror attacks. In Biological Weapons (2005), Jeanne Guillemin writes that the establishment of the US Department of Homeland Security (DHS) in 2003 “far outweighed the diffuse, decentralized domestic preparedness project of the previous decade.”

Threats

The Homeland Security Act of November 25, 2003, incorporated the Federal Emergency Management Agency (FEMA), which immediately dedicated resources to investigate the
threat of biological terrorism. FEMA concluded that three groups of biological
agents could be used as weapons: bacteria, viruses, and toxins. Though terrorists
may choose biological warfare over other tactics, most known agents are difficult
to cultivate and are quickly destroyed once exposed to dry air and sunlight. For
example, though the airborne spread of plague is possible, Y.
pestis bacteria survive up to one hour only once released. Some
agents, like the smallpox virus, are spread only through human contact, while
others, like anthrax, infect only those exposed to a primary source of the germs.
However, terrorists could choose to release germs that infect animals bred for
human consumption or could choose to contaminate water supplies.

In December 2008, a bipartisan panel commissioned by the US Congress to analyze the threat of unconventional weapons warned that, unless the international community commits to preventive measures and additional security, “it is more likely than not that a weapon of mass destruction will be used in a terrorist attack somewhere in the world by the end of 2013.” The panel called for the strengthening of international organizations dedicated to preventing unconventional warfare, to improving rapid-response and bioforensic capabilities, to heightening security at research institutions housing biological pathogens, and to forming an international conference on biosecurity. Notably, the report concluded that weaponizing biological agents is extremely difficult and likely outside the range of capabilities for a rogue, non-state-supported group. Before leaving office in January 2009, US president George W. Bush signed an executive order on laboratory biosecurity that established an interagency body dedicated to regulating and overseeing research programs and laboratories.

The warning about the potential for breaching the security of state-sponsored programs relates to lessons learned following events in 2001, when anthrax was spread through an infected powder sent with letters through the US postal system. The anthrax-laced letters were targeted to persons in media and politics, resulting in twenty-two documented cases of anthrax infection. Analysis of the infected letters pointed to the Ames strain, the form grown and studied in the US program. A federal investigation later identified the anthrax source as the laboratory of Bruce Ivins of the US Army research facility at Fort Detrick, Maryland.

Federal agencies and politicians continue to incorporate the threat of biological terrorism into national security regulations and policies. The next-generation threat to US security is lax security at labs researching diseases that could be cultivated for biological weapons. In mid-October 2010, Jacek Bylica, head of the Weapons of Mass Destruction Centre of the North Atlantic Treaty Organization, said that the spread of weapons of mass destruction, their delivery, and the chance that terrorists will acquire them are major, significant threats. In November, bioterrorism security concerns were again raised when US senator Richard G. Lugar and Pentagon officials visited Uganda’s ministry of agriculture, animals, industry, and fisheries. Discovered there were research specimens of anthrax and the Ebola and Marburg viruses, stored in an unlocked refrigerator in an unsecured building.

Government watchdogs have also continued to audit the BioWatch program that was put in place by the DHS two years after the anthrax attacks of 2001. The second adaptation of the system has been in place since 2005 and consists of aerosol collectors positioned in thirty cities across the country designed to detect pathogens that could signal the threat of a biological attack. Filters must be manually removed and checked for the presence of pathogens regularly. Because this process has proved time consuming, by 2015 the DHS had proposed instituting a more automated system. However, such plans were put on hold and the system was once again questioned after the Government Accountability Office released a report stating that the costly system had not yet proven its current capabilities and had recorded several false positives since 2003.

Response

In response to the threat of bioterrorism, the DHS works to determine the agents that are easiest to grow and deliberately release and seeks to develop methods for identifying the natural outbreak of a disease from a bioterrorism attack. In 2004, the DHS established the Knowledge Center, which provides a collaborative forum for experts in biological pathogens and political terrorism to share information and assess bioterror threats.

The CDC and the American Red Cross prepare populations for a bioterrorism attack through multimedia educational programs that urge families to store supplies, that show how to detect signs and symptoms of biological terror agents, and that show how to deal with exposure to suspected biological agents, among other topics. According to FEMA, optimal prevention against a bioterrorism attack includes installing a high-efficiency particulate-air filter in furnaces and ensuring that recommended immunizations are updated for all persons.

In preparation for a possible aerosol attack of the pneumonic plague agent or the tularemia agent, national and state health centers have stockpiled antibiotics. The CDC also maintains an antitoxin to treat botulism. Though there have been no known cases of smallpox since 1977, and routine vaccination against the disease has been discontinued, the United States now secures research and treatment stockpiles of the Variola virus. No plague vaccine is available in the United States, but research for such a vaccine continues.

Prevention

A June 2010 report from the Center for Biosecurity at the University of Pittsburgh Medical Center stated that from 2008 through 2010, government spending to support biodefense programs increased. Bioterrorism prevention and intervention are top priorities, according to Department of Health and Human Services secretary Kathleen Sebelius, who, in early 2010, announced a new national health security strategy of focusing resources on first-responder teams and front-line health care. On October 7, the National Institute of Allergy and Infectious Diseases announced its investment of $68 million in research projects for the development of vaccines to protect against biological terror. These projects include those looking into a needle-free dengue vaccine, an orally administered anthrax vaccine, and an anthrax vaccine administered with an adjuvant to stimulate the immune system. On November 5, the Biomedical Advanced Research and Development Authority of the HHS awarded Northrop Grumman a one-year contract to develop a biodefense system to allow first-responders to rapidly screen and triage persons exposed to a biological agent.

Impact

Because there have been few incidents of bioterrorism, there is little historical data on its impact. However, scientific predictions about likely effects on populations have led to response strategies and to investment in prevention and detection technologies.

Bibliography

Guillemin, Jeanne. Biological Weapons. New York: Columbia UP, 2005. Print.

Isikoff, Michael. “The Case Still Isn’t Closed.” Newsweek 18 Aug. 2008: 152. Print.

Kron, Josh. “Uganda Seen as a Front Line in the Bioterrorism Fight.” New York Times 11 Nov. 2010: A8. Print.

Markon, Jerry. "A Decade in, DHS Program to Detect Bio-Threats May Not Be Able to Detect Bio-Threats, Auditors Say." Washington Post. Washington Post, 25 Nov. 2015. Web. 29 Dec. 2015.

Miller, Judith, et al. Germs: Biological Weapons and America’s Secret War. New York: Simon, 2002. Print.

Rosebury, Theodor. Peace or Pestilence: Biological Warfare and How to Avoid It. New York: McGraw, 1949. Print.

Spiers, Edward M. A History of Chemical and Biological Weapons. London: Reaktion, 2010. Print.