Bio-terrorism, for real

The growing number of anthrax cases in the United States indicates that bio-terrorism has arrived. The best response to this can be in terms of prevention of the disease that might result from the attack.

THE mounting cases of anthrax in urban America strongly suggest an attack of biological terrorism. Anthrax, an infectious bacterial disease of animals that can be transmitted to humans, is being delivered, in this instance, through the most unconventional mode, the postal mail. What was a spectre for the West for a decade since the apparent discovery of covert chemical weapon and biological weapon programmes in Iraq, bio-terrorism is now for real. The hoax anthrax attacks in the United States in the past few years may well have been the trial runs.

There have been a number of incidents related to threats, preparation for use or actual use of biological weapons by terrorists in the past. Some of them are:

* 1972: Members of the fascist group Order of the Rising Sun in the U.S. were found in possession of 30 to 40 kg of typhoid bacteria cultures for use against water supplies in major mid-west cities;

* 1980: the Bader-Meinhof gang of Germany was discovered to possess a Clostridium botulinum culture and a biological laboratory in a Paris apartment;

* 1986: The Rajneesh cult in Dalles, Oregon, allegedly used Salmonella typhi to contaminate salad bars in local restaurants in order to influence the outcome of a local election (751 cases resulted);

* 1990-94: The Japanese religious cult Aum Shinrikyo attempted on nine occasions to spray anthrax spores and botulinum toxin aerosol in Tokyo and nearby areas (the agents it produced had no effect on the population).

The current sequence of events would, in fact, represent the first confirmed case of bio-terrorism after the 1991 Gulf war. According to a database of various reported incidents of bio-terrorism compiled by the Monterey Institute, Centre for Non-Proliferation Studies, only one person was killed in the U.S. by bio- or chemical terrorism in all of the 20th century.

With a single data point relating to the present anthrax-related events, one cannot realistically discuss the epidemiology of bio-terrorism even within the American context. The extent of the threat, the risk it poses to the civilian population, and the medical and other counter-measures that must be deployed cannot, therefore, be assessed with any degree of accuracy. Indeed, none of the scenarios of a possible attack that had been built by counter-terrorism strategists in the West included anything like the events currently in evidence - letters laden with anthrax - the first of which was detected on October 5 in a media office in Florida. It is not obvious that the events are linked to the suicide aircraft crashes of September 11. Given the incubation period of anthrax infection of up to six weeks, the attacks may have even preceded September 11. The individual or the group or the state responsible for these may not even have anything to do with Al Qaeda, the terrorist group headed by Osama bin Laden, suspected to be behind the September 11 crashes.

BIO-TERRORISM needs to be distinguished from bio-warfare. While the weapons and, to an extent, the tools used are the same in the two, the objective and the modus operandi are vastly different. The objectives of the latter are in terms of military gains to be achieved, while the former aims to create panic and fear in the civilian population and disrupt normal civic and/or political life of the targeted country or group.

Agents of biological warfare include living micro-organisms (bacteria, rickettsia, viruses, chlamydia, fungi) capable of entering the human body (by inhalation or ingestion), multiplying and causing illness and death - some of these can even produce epidemics. They also include toxins produced by micro-organisms, plants or animals (or synthetic analogues of naturally occurring toxins), and chemicals that regulate biological functions.

The last category of agents (such as hormones and peptides) has normal physiological effects in low and moderate doses and patho-physiological effects in high doses. Unlike living micro-organisms, toxins and bio-regulators only affect people directly exposed to them and cannot pass from person to person. The production of biological weapons for offensive use is prohibited by the Biological and Toxin Weapon Convention (BWC) of 1972. However, the BWC allows research and development in biological warfare agents for defensive purposes - for example, development of vaccines and treatment against biological weapons - and it has no mechanism to monitor the activities of its member countries. The verification protocol has been under negotiation for a decade now with the aim of concluding a regime by November 2001. Ironically, the Bush administration, which in July rejected the protocol saying that the verification mechanism proposed would be ineffective, has suffered the first attack of bio-terrorism.

Compared to other weapons of mass destruction - chemical, radiological or nuclear - biological weapons are more attractive for several reasons. Since agents of biological warfare agents are living organisms that reproduce inside the host, they are much more potent per unit weight. As against chemical warfare agents, which must be stockpiled in hundreds and thousands of tonnes to be effective militarily, a few kilograms of a biological warfare agent, such as anthrax bacteria, can cause comparable levels of damage. From the perspective of bio-terrorism, small quantities would suffice. Such amounts can easily be smuggled into and out of countries and are also easy to hide. The freeze-dried form of the agent can even be transported across borders in small amounts in parcels over a period by ordinary mail and stockpiled in the target country itself. The smuggling in of narcotics in large quantities without being detected points to the difficulty in detecting the entry of agents of biological warfare. Alternatively, seed cultures could be smuggled in and the agents produced in clandestine laboratories in the target country.

Because of the potency of the agents and the exponential growth of the organism in the host, small quantities can be produced in a matter of days. While the lengthy incubation period of infection is a severe constraint on the battlefield utility of biological weapons - except in situations of attrition warfare - it may be advantageous for terrorism. It gives time for the perpetrator to be thousands of kilometres away after committing the act. In some cases, it may even remain undiscovered because the disease pattern could not be distinguished from a natural outbreak. Because of the delayed effects, a terrorist act could include the use of biological weapons against crops and livestock.

Whereas the production of chemical weapons requires certain key precursor chemicals - whose trade is controlled and regulated under the Chemical Weapons Convention (CWC) of 1997 - and process equipment and leaves behind tell-tale signatures, the production of biological agents involves materials and equipment that are almost entirely dual-use, with applications in pharmaceutical, cosmetic, food and pesticide industries. Much of the information is available in open literature. Clandestine biological weapon production can be carried on under the garb of legitimate biotechnology industry. Laboratory-scale capability for production of biological agents is sufficient to achieve most terrorist purposes. Whereas a typical vaccine production facility costs a minimum of $50 million, a much less elaborate fermentation plant suitable for conversion to a facility for the production of the biological weapons could be built with about $10 million.

Except for a small seed stock of the pathogen, no specialised starting materials are required. Nutrients such as fermentation medium, glucose, phosphates, peptone and a protein source (casein, electrodialised whey or beef bouillon) are widely available and are routinely imported into countries that have commercial fermentation industries. A small vial of freeze-dried seed culture, grown in a fermenter in a nutrient medium kept at a constant temperature, can result in kilograms of product (like anthrax bacteria) in less than 96 hours. Since working with pathogenic micro-organisms is extremely hazardous, specialised physical containment or "barrier" measures would be needed in a large-scale biological weapons facility to protect workers of the plant and surrounding population from infection. However, a facility meant for terrorist use is hardly likely to be concerned with such protective measures. Only those handling the pathogens would be individually protected by vaccines and, may be, by some protective clothing.

Once the biological agents are produced, it is necessary to process them into a form that enhances their stability in storage and after dispersal. This is the most difficult part from the perspective of a terrorist organisation. Living organisms will eventually deteriorate unless their metabolism is slowed down or stopped. Such a process of suspended animation naturally occurs in spore-forming bacteria like anthrax. Anthrax can survive in its dormant spore form for decades. This is yet another reason for it to be a favoured agent for bio-terrorism. Non-spore-forming microbes and most toxins, however, need to be converted into some stable form.

One method of enhancing the stability is rapid freezing and subsequent dehydration under high vacuum, a process known as freeze-drying or lyophilisation. In a few hours, a lyophiliser, a device mainly used in the pharmaceutical industry, reduces a solution of bacteria and a sugar stabiliser to a small cake of dried material that can be milled into powder form. Lyophilisation makes possible a significant increase in the potency of the biological agent by direct inhalation of its particles into the lungs. This technique is also applicable to toxins. While for anthrax, which is very easy to grow, lyophilisation is not needed, even a small-scale unit can be equipped with lyophilisers required for other organisms.

Having produced an agent of biological warfare, it must also be delivered to a target. In the powder form, as in the present anthrax-related cases, the impact of the attack remains localised. One of the simplest methods to achieve attack over a widespread area is to turn the spore or freeze-dried powder into a biological "aerosol" - a stable cloud of suspended microscopic droplets, each containing from one to thousands of bacterial or virus particles. The droplets can remain suspended in the air for long and can be carried by wind over large distances. Biological aerosols can be produced with a relatively simple piece of machinery that sprays a suspension of micro-organisms through fine nozzles, converting about 85 per cent of the starting material into droplets in the desired size range. Aerosol dissemination and the consequent respiratory infection circumvent the normal protective mechanisms and increase the virulence of pathogens that normally have low lethality. For example, untreated skin or cutaneous anthrax is fatal only in about 5 per cent of the cases, whereas pulmonary anthrax is fatal in more than 90 per cent of the cases.

Besides, aerosolisation of biological agents would be the preferred method for terrorist attacks - as in the Aum Shinrikyo case - since extreme physical conditions associated with explosive dissemination, as in the case of bombs, can result in complete loss of bio-activity. Aerosol dispersal also allows for control of the particle size and density to maximise protection from environmental degradation and the uptake of the enclosed biological agent in the lungs of the targeted population. A widely held view, even among experts, is that, except for the delivery component - namely, either in the freeze-dried, finely powdered form or by aerosolisation - all other steps are accessible to a terrorist organisation.

In this context, it is instructive to consider the analysis of the experience of Aum Shinrikyo done by Milton Leitenberg of the Centre for International and Security Studies, University of Maryland.

The Japanese group had unlimited funds to procure appropriate equipment, which it did through front companies. It had adequate facilities and four years to work undisturbed. It had about a dozen people with graduate training. It had attempted to buy assistance and technology in the Soviet Union to aid its efforts to produce biological weapons, but despite spending millions of dollars, it failed. "This last point is particularly important with regard to the frequently expressed fear of the likely ease of procuring such information from unemployed or poorly paid former Soviet experts," says Leitenberg.

The Aum group had attempted to produce two biological agents: the botulinum toxin and anthrax. Since it failed in either case, its efforts to "disperse" these also had no effect. According to Leitenberg, it tried to purchase a Q-fever culture from a Japanese researcher but was rebuffed. Its members travelled to Africa to get samples of the Ebola virus, but failed. Leitenberg argues that the widely held opinion that terrorist organisations can easily acquire the capability to produce agents of biological warfare is grossly exaggerated. Indeed, even the present sequence of events, where the high purity of anthrax bacteria seen points to a sophisticated production source, would seem to imply that whosoever committed the attack has simply acquired the final product rather than having acquired the capability to produce the agents. It is possible that the attackers had access to agents of biological warfare produced by the former Soviet Union in some of the Central Asian republics.

The only response and counter-measures to this emerging threat of bio-terrorism can be in terms of prevention of the disease that might result from the attack. While prophylactic vaccination against pathogens that terrorists might use is possible for the military, it is not a feasible proposition in the case of a civilian population. The Union Health Minister's statement that the anthrax vaccine will be produced needs to be viewed in this light. In any case, the technology to produce the vaccine is not easily available. It is produced by one American company, for the U.S. armed forces. Also, it cannot be known as to which biological agent is likely to be used, and the public cannot be vaccinated against all possible biological weapons.

The only reasonable counter measure is to acquire the ability to recognise that there has been an attack and to institute prompt preventive measures such as post-exposure vaccination and therapy. All health care providers should have basic epidemiological skills and the knowledge to discern a pattern of infection or disease that differs from a natural outbreak. A sensible response to a disease outbreak resulting from bio-terrorism should include proper case definitions of possible diseases, rapid diagnostic facilities and timely availability of preventive and therapeutic measures. In the Indian context this would indeed be a difficult proposition, given the lack of adequate health infrastructure even for common diseases.