Courcy's Future Threats - April 2014

The major focus of responders and policy makers to the ongoing Ebola outbreak in West Africa is public health, and that is as it should be. However, when looking to the future it would be remiss not to consider the potential for bioterrorism. Viral haemorrhagic fevers, particularly the Zaire strain of the Ebola virus, could be terrible weapons if they fell into the wrong hands.

At the time of writing, there have been 281 confirmed cases in the current outbreak, of which 186 are known to have died. Most of these have been in the south-east region of Guinea, with some cases (and deaths) also occurring over the border in the neighbouring countries of Liberia and Sierra Leone; many more cases are suspected. The strain of the virus is now known to be the Zaire species, the most deadly form of the disease (see tables), although tests on recent patients suggest the Guinea outbreak pathogen is a different clade to the Zaire species responsible for outbreaks in other parts of Africa.

The current outbreak is unprecedented for two reasons. Firstly, Ebola outbreaks normally occur in eastern and southern Africa (there was a single confirmed case in Cote d’Ivoire in 1994, but the patient survived). Either the disease has spread to new parts of Africa, or, more likely, as people make greater and greater incursions into the forests they are coming into contact with hitherto unknown reservoirs of the disease. The primary reservoir of Ebola is not known. Many researchers believe patients who pick up the disease in the wild do so from animals such as monkeys, which are often consumed as bush meat, although they are not necessarily the reservoir and could just be a step in the infection chain (just as camels appear to be a step in the infection chain for MERS, but not the original reservoir).

Secondly, the geographical spread of the outbreak is much larger than usual. The original outbreak was discovered in south-eastern Guinea. Cases have been since been reported in Conakry, the capital of Guinea, a city of a million and a half people, over 400 miles away from the region that saw the initial cases. The disease has also spread across the borders to neighbouring Liberia and Sierra Leone. Controlling the spread of the disease has proved impossible so far, not helped by the fact that it took the authorities six weeks to identity and react to the outbreak.

“We are facing an epidemic of a magnitude never before seen in terms of the distribution of cases,” Mariano Lugli, a co-ordinator in Guinea for Medecins Sans Frontieres (MSF) said. “This geographical spread is worrisome because it will greatly complicate the tasks of the organisations working to control the epidemic.”

The scale of the current outbreak could set a worrying precedent. Until recently the virulence of the disease is actually what has prevented large-scale outbreaks. Travelling from rural areas to cities in remote parts of Africa can be difficult and arduous; journeys often have to be made on foot over long distances. When people in isolated communities have become infected they have usually been too ill to travel, even if they had the desire to, allowing the disease to burn itself out. But as technology improves and people can travel more easily, the chances that infected people will survive the journey to larger population centres increase.

An additional difficulty for responders is the reaction of the uneducated and superstitious population, particularly in the poorest areas, who are often suspicious of visiting medical teams from MSF and United Nations agencies. According to an official in Sierra Leone, six patients (four of whom had been confirmed as having Ebola and the other two suspected) have been “aggressively” taken away from a clinic by their relatives, in defiance of medical staff; one of them is known to have died so far and it is not yet clear how many other people might have been infected. It is not known why the relatives took the patients away.

Malicious intent

As more outbreaks of Ebola occur, two things are likely to happen: firstly, people who are looking for ways to create terror will become more aware of the virus and what damage it can do; and secondly, there will be more opportunities to collect a sample of the virus.

When people think about bioterrorism they often imagine high-tech methods of distribution, such as using military equipment to maximise the effect of the bio-agent. But terrorism, including bio-terrorism, does not have to be high-tech. Researchers and scholars have posited that a low-tech approach could be particularly effective. In the book Tangled roots: Social and psychological factors in the genesis of terrorism Valenty Shepherd suggests that “[b]ioterrorism using human beings as the vector from which the biological ‘bomb’ would ensue” would be an effective method of spreading the disease.

The Ebola virus possesses many qualities that could make it an attractive weapon to a terrorist. Firstly, it can be difficult to diagnose in the first instance. Initially the disease presents with symptoms that are commonly associated with other diseases. A person with Ebola hemorrhagic fever exhibiting symptoms typical of common tropical diseases can be misdiagnosed and mistreated, and quarantine measures may not be taken as early as they ought to be. If the disease is being spread in a highly populated area then the number of people infected could be huge before the authorities realise what is happening and are able to respond.

There is no known cure for Ebola haemorrhagic fever. The only option is to isolate the infected person to prevent the disease being passed on any further, and treat the symptoms in the hope the patient is strong enough to pull through. Researchers have been working on some cures that look promising, but there is nothing available yet. Tests on monkeys have showed that a particular cocktail of drugs given at the right time can provide a cure in some animals, but there is still much work to be done before human trials can be performed.

The nature of the disease (suffering a haemorrhagic fever is a truly horrible experience) and the lack of a cure make the disease particularly terrifying. This in turn makes the virus an even more tempting weapon, as generating fear in a target group or population is central to any terrorist attack. That being said, if the tactic in question is a suicide attack the perpetrators need to be prepared for the fact that their death will be protracted and unpleasant; a suicide bomb is, at least, quick.

It is important to remember that no terrorist attack has yet been perpetrated using the Ebola virus, although Aum Shinrikyo is known to have attempted to harvest samples of the virus for development into a weapon. There are also other examples of attempts at bioterrorism in recent times, some more successful than others. The most prominent is the 2001 Amerithrax attacks, in which a rogue US researcher sent anthrax through the post. Aum Shinrikyo (as well as its abortive attempts to harvest Ebola, and it’s more famous Sarin attacks on the Matsumoto and Tokyo subway systems), also attempted to use both anthrax and botulinum toxin as weapons.

Much has been made of the ‘de-skilling’ of advanced techniques. A combination of an increase in availability of education, thus potentially increasing the skill set of potential terrorists, and advances in technology, meaning less scientific knowledge is required to handle and manipulate pathogens, suggests that someone using a crude bio-weapon is becoming increasingly likely.

Not all scholars agree that a large-scale bio-terrorist attack is imminent. In his 2011 article Could terrorists exploit synthetic biology? Tucker concludes that “a gradual decline in the amount of tacit knowledge required to master the technology that will eventually make it accessible to non-experts, including those with malicious intent” will not occur in the very near future, but he does not rule it out completely. Furthermore, he is referring to highly advanced techniques required to manipulate pathogens into more deadly forms and weaponise them. The knowledge gap required to harvest a wild pathogen and release it via a human vector in a populated area is much smaller, and shrinking.

As more people come into contact with the wild jungle in Africa, so they will be increasingly prone to infections with virulent zoonoses, including the Ebola virus. It seems increasingly likely that future outbreaks of Ebola haemorrhagic fever are going to put large numbers of people at risk, as infected people are increasingly able to travel to cities to seek help.

Where in the past outbreaks have been devastating to a small population, but ultimately isolated, we may be seeing a new paradigm in the pattern of infections, more like a ‘flu virus working its way through population. This in itself is a worrying prospect, but it is even more so when coupled with the prospect that someone might seek to harvest and deploy it as an act of terrorism.

When the dust has settled after the current west-African outbreak has subsided, authorities would be unwise to ignore the possibilities increased access to this pathogen present to those with malicious intent.