Images of humans infected with Ebola Virus Disease, a strain of viral hemorrhagic fever (VHF), instill public fear and panic. Ebola is a naturally occurring virus with no known natural reservoir.[1] In addition to the innate fear that the deadly virus inspires, a further fear stems from questions about Ebola’s potential use as a bioweapon. Ebola is not a new disease. The virus first emerged in 1976 with two simultaneous outbreaks in Sudan and Zaire (now the Democratic Republic of the Congo).[2] The disease is named after the Ebola River in Congo on which the Yambuku village, one of the original outbreak villages, is located.[3] After 38 years of scientific study and effective management, Ebola remains a public concern today. There is some apprehension about the potential for its conversion into a bioweapon by a terrorist group.[4]
The U.S. Centers for Disease Control and Prevention (CDC) categorizes VHFs as a Category A bioterrorism disease.[5] This designation is based on the ease of their dissemination,[6] their high mortality rates, their potential to cause public panic, and the special preparedness they demand for public health protection. As of September 19, 2014, the CDC has confirmed 3,341 cases of Ebola in the most recent outbreak and 2,811 deaths across five West African states.[7] The World Health Organization estimates the mortality rate at about 70%.[8] Transmission of the virus to humans occurs through direct contact of bodily fluids such as blood, secretions, and other contaminated fluids. The transmission of the fluid occurs through broken skin, mucous membranes, or eating infected tissues such as bush meat. Upon infection of its victims, the acute viral illness is characterized by “sudden onset of fever, intense weakness, muscle pain, headache, sore throat; followed by vomiting, diarrhea, rash, impaired liver and kidney function and in some cases both internal and external bleeding.”[9]
The prevalence and pathogenicity of Ebola as well as the proximity of the outbreak to terrorist organizations such as Boko Haram in Nigeria pose the question: could Ebola be used as a bioweapon? Dr. Vladimir Nikiforov, head of the Department of Infectious Diseases at Russia’s Federal Medical-Biological Agency, has claimed publicly that Ebola could be turned into a biological weapon.[10] Ken Alibek, the former deputy head of the Soviet Union’s biological weapons program, explained in his book Biohazard that the Soviet Union weaponized Ebola during the Cold War.[11]
Despite previous work conducted by the Soviet Union and current assertions by some in the media, Ebola is not an ideal bioweapon.[12] This article examines the extreme difficulty a terrorist organization would face in weaponizing Ebola as well as challenges several non-conventional employment options of Ebola. This article finds that, despite the outbreak’s location in West Africa, terrorist groups such as Boko Haram lack the knowledge and specialized equipment necessary to employ Ebola as a bioweapon.
Ebola as a Bioweapon?
Biological weapons, unlike conventional munitions, have extensive reach capabilities. “Biological agents can produce lethal or incapacitating effects over an extensive area and can reproduce,” according to the Department of Defense.[13] Bioweapons are not limited by the blast radius of a shell; rather, they can replicate in an infected host and spread from one person to another. For Ebola to be used as a bioweapon in its naturally occurring state requires several highly technical steps. Ideal bioweapons, for example, are aerosolizable in order to infect mass numbers of people quickly.
In an interview with CBS News, Hamish de Bretton-Gordon, the chief operating officer of SecureBio, stated that for a terrorist group to use Ebola as a bioweapon, the group must first “obtain a live host infected with the virus,”[14] then transport the host to a laboratory to extract the virus. Extracting the virus is not a simple process. The flu virus, for example, is approximately 100 nanometers in size, so the laboratory must have the necessary extraction equipment and personnel trained to complete the skilled techniques, all within the required biosafety level so that the technicians would not become infected themselves. Furthermore, the skills required to extract Ebola from blood are only gained through practice. The training and time required to extract a virus from blood correctly is significant, making the trained personnel capable of extracting Ebola a highly coveted commodity for a terrorist organization seeking to use the virus. Such personnel must operate in the necessary protective equipment to shield them from inadvertent transmission. Failure to work in what is deemed a biosafety level 4 lab, of which there are only about two dozen worldwide, would likely not result in successful extraction but almost assuredly death of the handlers.[15]
A study conducted by the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) demonstrated that Ebola could be transmitted in an aerosolized form, but their research is not based on realistic scenarios.[16] The rhesus monkeys used in their 1995 study were forced to inhale large quantities of droplets via a breathing apparatus[17] containing the Ebola virus.[18] Instead of the typical fluid-to-fluid transmission of Ebola, the monkeys contracted the virus via highly concentrated exposure to their respiratory mucous membranes. Moreover, these experiments were done in an extremely controlled biosafety level 4 environment, and the monkeys themselves were anesthetized during the infection process. The labs at USAMRIID have tremendous resources and technical expertise to conduct aerogenic infection experiments of Ebola, which terrorists groups like Boko Haram currently lack.
Ebola is also not a robust virus; it does not survive well outside of the host. Samples, consequently, cannot be extracted from an infected host and frozen for later use. As de Bretton-Gordon explained, “the reason anthrax has been the biological weapon of choice is not for its mortality rate—when properly weaponized it is similar to Ebola—but for the fact that it is exceptionally hardy. Anthrax can and will survive for centuries in the ground, enduring frosts, extreme temperatures, wind, drought, and rain before reemerging.”[19]
In the 1970s, the World Health Organization studied the effects of aerosolized Rift Valley Fever, another VHF strain. The WHO projected that the effects of 50 kilograms of aerosolized RVF on a municipality of 500,000 would have an estimated downwind distance of one kilometer and cause 35,000 casualties with a mortality rate of 0.5%.[20] Ebola has a higher morbidity and mortality rate than Rift Valley Fever. Fifty kilograms of Ebola is an astronomical amount for a terrorist group to culture and purify.[21] In his book Biohazard, Ken Alibek, the former deputy head of the Soviet Union’s biological weapons program, detailed how the Soviet Union spent billions of dollars and decades working to weaponize Ebola, to little avail.[22] Technology, expertise, and vast amounts of money are the three necessary components to weaponizing Ebola that a terrorist organization simply does not possess.
A Limited Bioweapon?
The Ebola virus is clearly not an ideal conventional bioweapon. The virus is extremely debilitating and requires specialized equipment and expertise for handling. Additionally, large quantities of the virus must be cultured to create the virus-containing droplets to aerogenically spread the virus. Otherwise, transmission is limited to direct contact.
Ebola as an unconventional bioweapon, however, is a concern. Nevertheless, the risks and concerns are considerably different. The recent stabbing of a federal air marshal at Lagos airport in Nigeria with a syringe highlights a potential means for terrorist organizations to spread the virus.[23] With this method, however, the victim would know that they had been potentially exposed to a pathogen. Attack with a syringe or any other obvious delivery system would prompt the victim to seek immediate medical attention. The victim would be tested for a wide array of chemicals and agents as well as likely undergo precautionary quarantine—which is what occurred to the federal air marshal in Nigeria—to ensure they were not exposed to Ebola. The syringe in this case was also sent to the biodefense laboratory at Fort Detrick, Maryland, for further inspection.[24]
Another plausible means for a terrorist group to spread Ebola would be to infect themselves and then attempt to spread the virus to others by spending time in confined public spaces, such as in an airplane or bus.
In such a scenario, the time period between when the terrorist has a high enough titter count of virus in his blood to infect others and when the terrorist himself is debilitated by the disease is extremely short. The virus that the terrorist would hope to spread to others would be concurrently killing its host. Consequently, it would be a race between contagion of others and the death of the terrorist. As the virus replicates, the body becomes more and more incapacitated. The white blood cell count drops and bodily functions diminish. The terrorist would appear sick, alerting those in his vicinity to avoid him. The virus is not airborne, so the terrorist’s ability to move around as a kind of human viral bomb is negligible since he must come into direct physical contact with others to spread fluids either through broken skin or mucous membrane.
Assuming a terrorist group succeeds in finding an ideal transmission window in which they could spread the virus unnoticed to others, the infection would be no different than a typical pandemic. The rate of infection and presentation of symptoms is not the same as a typical weapon of mass destruction. It would not pose a mass casualty threat. The biomedical surveillance capabilities of hospitals and health organizations in conjunction with the response of municipalities and governments around the world would enable a counter-response. Some individuals would invariably get sick, but they would be quarantined and receive medical care. City limits and borders could be closed to prevent the spread of the disease.
The risk of Ebola as an effective unconventional biological weapon is low. The aspects of the virus that support its classification as a potential bioweapon by the CDC are also the same factors that limit its capabilities as a functional bioweapon. Terrorist groups lack the technology, the safety equipment, and the expertise to make the virus into hearty, contagious bioweapons like Anthrax or Small Pox.
Conclusion
Ebola is a deadly disease. Like any biological agent, if given sufficient amount of time, money, and expertise under specific conditions, it could be turned into a biological weapon. The resources of groups such as Boko Haram and the Islamic State in Iraq and the Levant (ISIL) are not the same as the former Soviet Union, which spent billions of dollars and decades in secret laboratories working to weaponize Ebola. Despite reporting that ISIL has an estimated $2 billion in amassed wealth,[25] setting up a mobile laboratory capable of extracting Ebola from infected patients and transforming the cultured virus into a bioweapon is not likely a priority given the intensified fighting in Iraq and the proposed airstrikes in Syria. In the hands of terrorists, Ebola is perhaps more deadly for its own members who have minimal training with and knowledge of the virus.
As a non-conventional bioweapon, Ebola is also far from ideal. Ebola is not an aerosolized virus. Consequently, a terrorist organization would have to use very direct delivery methods for infection. Being accosted with a needle is noticeable to a victim, prompting them to seek medical attention and commencing containment procedures, if necessary.
If a terrorist organization sought to infect its own members, becoming in effect Ebola-infected suicide bombers, the short timeframe between when the virus count in the host would be high enough to infect others and when the host himself is debilitated by symptoms would prove highly limiting. The reach of such novel suicide bombers could be drastically reduced through biomedical surveillance networks in cities and hospitals around the world, aided by health screens at airports.
Ebola evokes images of a painful death, but to date its effect on humans has been relatively limited. Last year, malaria killed more than 627,000 people[26] worldwide, and influenza kills between 3,000 and 49,000 people annually in the United States.[27] Yet these two diseases are not considered potential bioweapons because, despite their high rates of infection, their mortality rates are low and do not cause general panic.
Fear of Ebola should not stem from its potential use as a biological weapon. Ebola is currently limited to a few West African states, and the real probability of Ebola spreading naturally to neighboring countries should itself be a cause for great public health concern. Claims that Ebola could be easily transformed into a biological weapon by a terrorist organization are unfounded and sensationalized.
Captain Stephen Hummel is a FA52 officer and currently serving as an instructor in the Chemistry and Life Science Department at the U.S. Military Academy, West Point. CPT Hummel previously served in both Iraq and Afghanistan and as the USAREUR CBRN plans officer.
The views presented are those of the author and do not necessarily represent the views of the Department of Defense, the U.S. Army, or any of its subordinate commands.
[1] A natural reservoir refers to the long term host of the pathogen. The hosts often do not get the disease or are asymptomatic for the infection. The World Health Organization considers fruit bats in Africa a possible natural reservoir for EVD and is considering the distribution of Ebola virus with the overlap of the fruit bats range. See “Ebola Virus Disease,” World Health Organization, April 2014.
[2] “Ebola Hemorrhagic Fever in Zaire, 1976,” Bulletin of World Health Organization 56 (1978), pp. 271-293.
[3] When the initial Ebola outbreak ended in 1976, 430 people were dead. Another outbreak occurred in the same region in 1995. See Ken Alibek, Biohazard (New York: Dell Publishing, 2000), p. 126.
[4] Elizabeth Palermo, “Could Ebola be Turned into a Bio-Weapon? Possible, but Not so Easy,” CBS News, August 11, 2014.
[5] “Bioterrorism Agents and Diseases,” Centers for Disease Control and Prevention, undated.
[6] Ease of dissemination refers to the person-to-person transmission of the disease. In the case of Ebola, transmission occurs through the passing of bodily fluids.
[7] “2014 Ebola Outbreak in West Africa,” Centers for Disease Control and Prevention, September 26, 2014. The five West African states that are reporting Ebola cases and deaths to the World Health Organization and the CDC are Guinea, Liberia, Nigeria, Senegal, and Sierra Leone.
[8] Christopher Dye et al., “The International Ebola Emergency,” The New England Journal of Medicine 371 (2014). This number is estimated due to underreporting in the number of Ebola cases. The death rate among laboratory confirmed cases is close to 84%, but the total number of cases (not laboratory confirmed) is reported to be 5,864, putting the death rate at close to 50%. The discrepancy in the mortality rate is due to reporting from rural villages and laboratory confirmation.
[9] “Ebola Virus Disease,” World Health Organization, April 2014.
[10] TJ Larson, “Top Medical Expert Calls Ebola Outbreak ‘Suspicious’; Others Cite Use as Bio-Weapon,” All Voices, August 9, 2014.
[11] Alibek.
[12] Palermo.
[13] “Chapter 1: Introduction, Potential Military Chemical/Biological Agents and Compounds,” U.S. Department of Defense, p. I-1.
[14] Palermo.
[15] The Biosafety Level 4 (BSL-4) is required for work with dangerous and exotic agents that pose a high risk of life threatening disease. The BSL-4 labs are specially designed and engineered to prevent microorganisms from being disseminated into the environment. All work in the lab is conducted in a positive pressure personnel suit to protect staff. See “Biosafety Level 4 Labs and BSL Information,” Federation of American Scientists, available at www.fas.org/programs/bio/biosafetylevels.html.
[16] E. Johnson, N. Jaax, J. White, and P. Jahrling, “Lethal Experimental Infections of Rhesus Monkeys by Aerosolized Ebola,” International Journal of Experimental Pathology 76 (1995): pp. 227-236.
[17] The virus containing droplets were 0.8 to 1.2 µm in size.
[18] Johnson et al.
[19] Palermo.
[20] “Health Aspects of Chemical and Biological Weapons,” World Health Organization Group of Consultants, 1970, pp. 98-109.
[21] To culture 50 kilograms of Ebola would consequently require tremendous resources to create an environment to keep cells alive in order for the cells to host a virus that is simultaneously killing the host cell it is using to replicate in.
[22] Alibek.
[23] “Air Marshal Attacked With Syringe in Nigeria, Flies to Texas,” NBC News, September 8, 2014.
[24] Andrew Pollack, “Stabbing with Syringe in Nigeria Raises Concerns of Ebola as Weapon,” New York Times, September 10, 2014.
[25] Howard Shatz, “To Defeat the Islamic State, Follow the Money,” Politico, September 10, 2014.
[26] “Fact Sheet on the World Malaria Report 2013,” World Health Organization, December 2013.
[27] “Estimating Seasonal Influenza-Associated Deaths in the United States: CDC Confirms Variability of Flu,” Centers for Disease Control and Prevention, September 12, 2013.
