Ebola and terrorism are not new. Nor is the possibility of terrorist groups using the Ebola virus in an attack. As we have previously noted, the Japanese cult Aum Shinrikyo attempted to obtain the Ebola virus as part of its biological warfare program. The group sent a medical team to Africa under the pretext of being aid workers with the intent of obtaining samples of the virus. It failed in that mission, but even if it had succeeded, the group would have faced the challenge of getting the sample back to its biological warfare laboratory in Japan. The Ebola virus is relatively fragile. Its lifetime on dry surfaces outside of a host is only a couple of hours, and while some studies have shown that the virus can survive on surfaces for days when still in bodily fluids, this requires ideal conditions that would be difficult to replicate during transport.
If the group had been able to get the virus back to its laboratory, it would have then faced the challenge of reproducing the Ebola virus with enough volume to be used in a large-scale biological warfare attack, similar to its failed attacks on Tokyo and other Japanese cities in which the group sprayed thousands of gallons of botulinum toxin and Anthrax spores. Reproducing the Ebola virus would present additional challenges because it is an extremely dangerous virus to work with. It has infected researchers, even when they were working in laboratories with advanced biosafety measures in place. Although Aum Shinrikyo had a large staff of trained scientists and a state-of-the-art biological weapons laboratory, it was still unable to effectively weaponize the virus.
The challenges Aum Shinrikyo's biological weapons program faced would be multiplied for the Islamic State. Aum Shinrikyo operatives were given a great deal of operational freedom until their plans were discovered after the 1995 sarin attacks on the Tokyo subway. (The group's previous biological weapons attacks were so unsuccessful that nobody knew they had been carried out until after its members were arrested and its chemical and biological weapons factories were raided.) Unlike the Japanese cult, the Islamic State's every move is under heavy scrutiny by most of the world's intelligence and security agencies. This means jihadist operatives would have far more difficulty assembling the personnel and equipment needed to construct a biological weapons laboratory. Since randomly encountering an infected Ebola patient would be unreliable, the group would have to travel to a country impacted by the outbreak. This would be a difficult task for the group to complete without drawing attention to itself. Furthermore, once group members reached the infected countries, they would have to enter quarantined areas of medical facilities, retrieve the samples and then escape the country unnoticed, since they could not count on randomly encountering an infected Ebola patient.
Even if Islamic State operatives were somehow able to accomplish all of this -- without killing themselves in the process -- Ebola is not an ideal biological warfare vector. The virus is hard to pass from person to person. In fact, on average, its basic reproductive rate (the average amount of people that are infected by an Ebola patient) is only between one and two people. There are far more infectious diseases such as measles, which has a basic reproductive rate of 12-18, or smallpox, which has a basic reproductive rate of five to seven. Even HIV, which is only passed via sexual contact or intravenous blood transmission, has a basic reproductive rate of two to five....
Even if a hostile group did mange to get an operative in place, it would still face several important obstacles. By the time Ebola patients are highly contagious, they are normally very ill and bedridden with high fever, fatigue, vomiting and diarrhea, meaning they are not strong enough to walk into a crowded area. The heat and shock of the suicide device's explosion would likely kill most of the virus. Anyone close enough to be exposed to the virus would also likely be injured by the blast and taken to a hospital, where they would then be quarantined and treated for the virus.
Biological weapons look great in the movies, but they are difficult and expensive to develop in real life. That is why we have rarely seen them used in terrorist attacks....
Read the entire article here.
This was actually a major plot device in Tom Clancy's last really great thriller novel, Executive Orders.
ReplyDelete"The group sent a medical team to Africa under the pretext of being aid workers with the intent of obtaining samples of the virus. It failed in that mission, but even if it had succeeded, the group would have faced the challenge of getting the sample back to its biological warfare laboratory in Japan… If the group had been able to get the virus back to its laboratory, it would have then faced the challenge of reproducing the Ebola virus with enough volume to be used in a large-scale biological warfare attack."
ReplyDeleteThat's a straw man. The question at issue is not getting a sample of the ebola virus to a bioweapon lab to reproduce. Rather, the question at issue is the more direct method of terrorists intentionally infecting themselves. You don't need a large volume of the virus. You only need a large volume of infected terrorists.
"Although Aum Shinrikyo had a large staff of trained scientists and a state-of-the-art biological weapons laboratory, it was still unable to effectively weaponize the virus."
That's a red herring. In the scenario under discussion, the *terrorist* is the carrier. The *terrorist* is the bioweapon.
"This means jihadist operatives would have far more difficulty assembling the personnel and equipment needed to construct a biological weapons laboratory. Since randomly encountering an infected Ebola patient would be unreliable, the group would have to travel to a country impacted by the outbreak. This would be a difficult task for the group to complete without drawing attention to itself. Furthermore, once group members reached the infected countries, they would have to enter quarantined areas of medical facilities, retrieve the samples and then escape the country unnoticed, since they could not count on randomly encountering an infected Ebola patient."
Once again, this is tilting at windmills. That's not the scenario under discussion. The hypothetic under review is terrorists who infect themselves by direct contact with those who already have it. The article keeps flailing away at a decoy.
"The virus is hard to pass from person to person."
That's what authorities keep telling us. Yet two nurses were infected despite ebola protective equipment–protocols which are nonexistent outside the hospital. If it's so hard to transmit, why does the CDC classify ebola as biosafety level four (BSL-4) pathogen?
"In fact, on average, its basic reproductive rate (the average amount of people that are infected by an Ebola patient) is only between one and two people."
So why does it multiply exponentially in Africa?
"There are far more infectious diseases such as measles…"
As I've pointed out before, that's a dumb comparison. There are two variables in the risk assessment: the risk *of* infection and the risk *if* infected. Even where the risk of infection is low, we take extraordinary precautions *if* infection has catastrophic consequences.
"The heat and shock of the suicide device's explosion would likely kill most of the virus."
An explosive device is not the scenario under review.
Steve:
DeleteThat's a straw man. (also "red herring", "tilting at windmills" and "decoys.
I don't know that it's a straw man or a red herring so much as the author is an analyst presenting (a) a real-life situation(s) and (b) relating the actual history of such an event ("attempts to weaponize Ebola"). Later in the article he does discuss the "terrorist-as-weapon" scenario.
re. "terrorists who infect themselves directly ..."
"The virus is hard to pass from person to person."
That's what authorities keep telling us. Yet two nurses were infected despite ebola protective equipment–protocols which are nonexistent outside the hospital. If it's so hard to transmit, why does the CDC classify ebola as biosafety level four (BSL-4) pathogen?
Don't get me wrong, I'm not saying that it's not a lethal disease. The question is "weaponization".
In its "Outbreak Update" the CDC does note that "this is the worst outbreak in history" (9911 "total cases" and 4868 "total deaths" as of October 22), and yet, in neaby Nigeria, where there have been 20 cases and 8 deaths, where travel would be much more extensive, and religious practices would be expected to be contribute to a similar type of outbreak, "The lines on the tabular situation reports, sent to WHO headquarters each day by its country office in Nigeria, have now been full of zeros for 42 days. On October 20, WHO officially declared that Nigeria is now free of Ebola virus transmission."
So, the disease (and the spread of it) does have its limits. It not only can, but is being contained.
Even where the risk of infection is low, we take extraordinary precautions *if* infection has catastrophic consequences.
Now that there is news of this infected doctor in New York City, I'm sure there WILL be extraordinary precautions everywhere.
The article also relates the difficulties now of any individuals traveling from African countries; the odds of known Islamists traveling go way down because, as the article says (not with respect to the "terrorist-as-weapon" scenario, but generally) "Islamic State's every move is under heavy scrutiny by most of the world's intelligence and security agencies."
So we are less likely going to look at a coordinated terror plan, but lone, and unknown individuals working to travel (from wherever) to Africa, contract the disease, then travel back to the US, and escape scrutiny that whole way. That seems not very likely to me at this point.
"Now that there is news of this infected doctor in New York City, I'm sure there WILL be extraordinary precautions everywhere."
DeleteWhy weren't there already "extraordinary precautions everywhere" since at least Duncan was diagnosed with Ebola in Dallas?
Why was a doctor who was known to have come from West Africa and known to have treated Ebola patients allowed to roam around NYC as he did?
Sorry for being a doubting Thomas, but speaking for myself I'd prefer to wait until there's actual evidence there are indeed "extraordinary precautions everywhere" before declaring "I'm sure there WILL be extraordinary precautions everywhere."
John, "Islamists don't have to travel to Africa." Africa has huge indigenous Muslim populations–including West Africa, which is the current epicenter of the Ebola epidemic.
DeleteI haven't suggested that Ebola as a Muslim bioweapon is the most likely threat we face from Ebola. I'm simply responding to the article on its own grounds.
I think the more threatening scenario is refugees fleeing from Ebola zones in Africa to North and South America, or Europe.
Steve's response is exactly what was running through my head when I read this. Anthrax doesn't spread from person to person the way Ebola does. Terrorists don't need to get Ebola in a lab or produce it in a lab. Aum Shinrikyo wasn't suicidal (from what I understand) the way terrorists are. The author talks about how hard it would be for terrorists to go to West Africa then into the US when they could simply recruit from West Africa or some other African nation with a heavy Muslim population and then send the person to Mexico or Canada. The author, amusingly enough, talks about how hard it is for Ebola to spread amidst an epidemic that we still haven't gotten under control and which has already appeared in Spain and the US.
ReplyDeleteHopefully the terrorists are as stilted in their thinking as this guy.
"The virus is hard to pass from person to person."
ReplyDeleteContrary to what the CDC tells us, it's possible people can be contagious without symptoms or at least realizing they have symptoms.
"In fact, on average, its basic reproductive rate (the average amount of people that are infected by an Ebola patient) is only between one and two people."
1. It's a bit of a misnomer to call this the "basic reproductive rate." A rate would have units of time. As epidemiologists and other statisticians have pointed out, R0 is a dimensionless number.
2. There are several models including mathematical models by which to derive R0. Which model is used is important to know. It's possible to level significant criticisms against various aspects of different models (e.g. the validity of a model, the relevance of a model to a particular population). Point being, we can and should examine the underlying assumptions of various models to see whether or not or to what extent a specific model is applicable to a specific scenario (e.g. are we referring to a closed or open population, are we assuming constant or variable rates of transmission).
3. At a minimum, we would have to take into consideration factors like incubation period of the pathogen, its transmissibility, its duration of infectiousness, contact rate (which is itself an average), etc.
4. There are different species of Ebola. At least to my knowledge, the R0 of 1 to 2 is a conglomerate of the different species rather than singling out a single Ebola virus (e.g. Zaire).
5. Different populations can be affected differently. For example, this recent article (2014) discussing the current outbreak in West Africa notes an RO of approximately 2.4 to 2.7 in Sierra Leone.
6. How much significant data do we have for the current Ebola species, which in turn may or may not be a distinct Ebola species (although it appears most related to Zaire)? If we don't have enough significant data, then we can't necessarily reliably calculate R0.
7. Compare Ebola to HIV. Strictly speaking, both appear to have similar R0s (or similar enough for my purposes here). However, an individual infected with HIV could be infectious for years, while an individual infected with Ebola could be infectious for weeks. Hence, if we were to incorporate units of time, then Ebola has a significantly higher number of infections per unit of time than HIV. R0 isn't necessarily the whole story.
Rocking -- As I've noted in my response to Steve above, the CDC has tracked "nothing but zeros for 42 days" in Nigeria, another country where there had been as many as 20 confirmed cases. So, whereas R0 numbers are perhaps accurate, (or as you say, "we can't necessarily and reliably calculate R0), there are limits to the spread of the disease, and those limits will become more apparent.
Delete"the CDC has tracked 'nothing but zeros for 42 days' in Nigeria, another country where there had been as many as 20 confirmed cases."
DeleteHm, I'm not sure why you bring up Nigeria? Is it to make the point that containing Ebola is possible? If so, this was never a point in dispute. A more pertinent issue would be whether we (or other nations) are doing a good job containing Ebola.
Is it to suggest the US is analogous to Nigeria in how Ebola is being handled? If so, how so? Just because Nigeria is doing a good job containing Ebola doesn't necessarily imply we (or other nations) are likewise doing a good job containing Ebola.
By the way, I think the Obama administration (among others) might do better to adopt some of what Nigeria has in place to handle Ebola if we wish to contain Ebola (e.g. better screening of travelers, keeping very close tabs on Ebola patient contacts as Nigeria does).
"So, whereas R0 numbers are perhaps accurate, (or as you say, 'we can't necessarily and reliably calculate R0')"
Actually, the way you phrase it, these would seem to run contrary to one another.
"there are limits to the spread of the disease, and those limits will become more apparent"
No doubt there are "limits." But to say there are "limits" is unfortunately rather vague. Too vague to be meaningful. For example, say a "limit" to the spread of Ebola is when 50% of all humans have died. That's a limit, but I would think it'd be a pretty unacceptable limit for most.
"In fact, on average, its basic reproductive rate (the average amount of people that are infected by an Ebola patient) is only between one and two people."
ReplyDeleteOf course, this is because up until now, the outbreaks have largely occurred in sparsely populated rural areas of Africa. And with it's relatively short incubation period, the virus doesn't have time to spread far before killing off its host. This leads to a couple of villages scattered about the jungle getting wiped out, but the surrounding area being unaffected.
But when a single person stumbles into a populated area while carrying the virus, usually dying in the local hospital, you have the larger outbreaks, although they are largely contained to the hospital staff and patients. The fact that the virus kills in such a terrifying manner means that most people who get it will try to get medical attention. This means that the hospitals will become the danger point, but it also means that there is a known focal point of the disease that well people can avoid--in essence, making a sort of natural quarantine. This is what keeps the R0 number low rather than some aspect of the virus itself: the virus is contained to remote villages and medical centers.
But if a terrorist is intent on spreading it far and wide, and they have infected themselves, I can foresee them going to heavily trafficked and popular areas and trying to run into contact with as many people as possible as soon as symptoms express themselves. They wouldn't be going to the hospital--they'd wait until they're *forced* into medical care after infecting as many as possible. Intentionally trying to expose the virus to more people, instead of incidentally exposing those at a common treatment point, just has to increase the number of people who would come down with the illness.
So yes, natural outbreaks (while still horrific) have a relatively low ultimate body count because of natural quarantines that arise through human behavior. But terrorists do not behave as a normal sick person would, so it would be foolish to assume the R0 number wouldn't be affected in a terrorist attack.
Well, now we have an opportunity to see how it works I'm real life as someone who has tested positive for the disease has now stumbled around New York City for a day.
ReplyDeleteThe argument is not that an ebola epidemic is likely, but that given the consequences if it were to occur, we should take extraordinary precautions.
DeleteI believe the person is in fact an emergency physician who worked with Ebola patients in West Africa. A few quick thoughts:
Delete1. Sure, he's a physician and should have known better than to wander around NYC shortly after arriving back home. That's probably where the authorities wish to place most of the blame.
2. At the same time, this arguably goes to show whatever measures we currently have in place to deal with Ebola aren't serious enough.
After all, one would think a person recently arriving from West Africa, who is a physician, who worked directly with Ebola patients, and who is now in the largest metropolitan city in the United States would be quite high on the "let's quarantine just to be safe" list, given the huge dangers of Ebola infection. Why not quarantine such individuals for a week or several weeks immediately upon arrival (as I think places like Hong Kong did during SARS and the bird flu)? See if symptoms develop before releasing him back to NYC.
3. This is another case where "self-quarantine" doesn't work.
The argument is not that an ebola epidemic is likely, but that given the consequences if it were to occur, we should take extraordinary precautions.
DeleteThis is only now coming into awareness. Even so, I don't doubt that "very good precautions" even now are being taken by first responders and medical facilities. I think that this is probably the last time we will see news about an infected man walking around NYC.
21 days is a very, very long time in internet media years. I'm sure that the precautions to be taken in that time will be far more "extraordinary" (in a very serious way) than we can imagine.
But again, as I said earlier, it will be interesting to compare what the predictions are vs what will have actually happened.
Rocking:
Delete1. You're right about this of course.
2. I don't think this lone doctor's actions reflects on "whatever measures we currently have in place". I think reflects maybe on his own lack of seriousness.
Here are some comments I recently made in an email exchange. Sorry, they're not organized well, but for what it's worth.
ReplyDelete(1)
No doubt good hygiene is important (e.g. not intimately handling a corpse infected with Ebola). No doubt Islamic and African superstitious beliefs hinder beneficial medical care too.
No doubt many aspects of our modern medical health care system aid in the care and support of Ebola patients.
That said, Ken Brantly (among others) can't keep donating his blood (convalescent serum). He's donated to Pham and others. I believe Writebol wanted to donate as well but hers didn't match in at least one case. Anyway, people like Brantly and Writebol are saints, but even saints don't have an endless blood supply before they need to rest and replenish themselves.
(As an aside, doctors suspect the convalescent serum is a key factor in people who recover from Ebola. But even this isn't totally certain. To my knowledge, it's a best guess sort of thing at the moment.)
Of course, I hope you're right [that medical science finds a cure soon].
But right now a vaccine looks far away. Best case scenario, probably several months away. Say the beginning of 2015. A worse case scenario would be never. Specifically, I believe the NIH has partnered with GSK in an attempt to develop a vaccine. There are other companies (as well as other nations) attempting to develop a vaccine. But do we even have data from phase 1 trials? Not that I'm aware of.
We have rough or approximate ideas, but even after all this time, we don't know the *exact* disease penetrance. We don't know the *exact* route of transmission. We don't know *exactly* who is susceptible and who isn't. We don't know if animals can serve as vectors to transmit Ebola to humans. And so on and so forth.
In fact, it's possible there's a pool of asymptomatic but contagious carriers in the US. If so, then Ebola could now be permanently endemic to the US, just like in Africa.
Of course, the bigger picture isn't solely about Ebola. Ebola is a scary disease, but there are many other arguably equally worrying diseases. Many awaiting us south of the border. What more could we be doing to better protect ourselves as a nation? It seems to me like we could be doing a lot more.
(2)
DeleteSorry, once again in a rush, so hopefully this isn't too abrupt sounding:
[In response to a question about being contagious only when symptoms appear.]
1. Actually, there's often a very blurry line between asymptomatic and symptomatic. For instance, take fever. Can we reasonably expect most people to recognize they have a low-grade fever, or would they just have a general sense of malaise?
2. Related, why establish thresholds for afebrile vs febrile in the first place? Originally the CDC stated 99.5F (or 37.5C) is afebrile but 100.4F (or 38.0C) is febrile. Then the CDC ended up revising the febrile threshold up to 101.5F or 38.6C. Normal body temperature is simply an aggregated average, and many people have normal ranges below or above 98.6F or 37C. It's possible someone with a low normal range becomes febrile but never reaches the CDC threshold.
3. Speaking of which, the CDC has had to continuously revise several key statements so far (e.g. Ebola won't spread to the US, current PPE guidelines are sufficient). I don't necessarily say this to suggest incompetence, although many others have done so. But I do think it suggests the CDC is reacting a lot more than acting. There's plenty of important questions we still don't know or understand about Ebola, yet the CDC keeps making confident or assured statements which they later have to "update." It'd be more honest to say something like, "Ok, we don't know, we're trying to figure it out." But I presume it's more politics driving than anything else, which is itself problematic.
4. Anyway, back to the topic. Point being, it's at least theoretically possible to be subclinically symptomatic and hence contagious (according to the CDC).
5. BTW, technically speaking, people who have survived Ebola like Brantly could still be infectious to some degree. The CDC has stated Ebola can survive in semen for up to 3 months. So if Brantly had sexual intercourse with his wife, then she could be at risk for Ebola since she presumably doesn't have antibodies in her system against Ebola like he does. I presume they're currently abstinent.
6. Also, BTW, Ebola (Reston) is airborne. It can spread through the air like the flu. Humans have been found with antibodies to Reston Ebola. I'm not making this up. Just Google. The US Army Medical Research Institute of Infectious Diseases has confirmed this. Although I suppose the reason this isn't big news is because Reston Ebola doesn't significantly harm humans.
However, a major concern would be if the current species of Ebola does mutate and become airborne. The likelihood of this currently looks low. But while we know a lot, we still don't know enough about Ebola's route(s) of transmission to be able to definitively rule it out.
7. Or if Ebola is able to be transmitted from, say, pigs to humans, and Ebola is found in pigs, and humans handle these pigs, then it could prove horrible. We don't know if certain animals can serve as vectors for Ebola. We know Ebola has been found in some dog species in West Africa, but without harm to the dogs. These dogs could transmit to humans.
8. Given some of this, why not have a third party assess people at high risk for Ebola (e.g. people traveling on West African passports)? Why not adopt what Hong Kong did during SARS and the avian flu? Such as using thermal imaging scanners to screen for early subtle changes in body temperature. Maybe there's a good reason we aren't implementing these sorts of measures, but I wonder what it is? To my knowledge, the gov't hasn't publicly addressed this. But my guess would be all this is too draconian sounding to a democracy. But I don't really know.
(3)
Delete[In response to a question about convalescent serum.]
Convalescent serum treatment is tricky business. There's so much to say on this that I unfortunately don't have the time to write it all out. So I'll say just a few things in no particular order, and maybe add more in the future if I have time:
1. To my knowledge, it's been a sheer coincidence that Brantly's serum has matched several of those infected with Ebola. I know Writebol's didn't match in at least one case (i.e. Duncan's). So there are no guarantees for whether a survivor's serum will necessarily match a recipient's.
After all, otherwise we could simply take serum donations from West Africans who have survived Ebola and use them in Americans, which isn't the case. (Although there are also logistical problems with this. For example, serum has a limited shelf-life, needs to be kept safe and secure during transport, refrigerated, etc.)
And obviously if we transfuse mismatched blood, then it could prove fatal to the recipient. (Just like in any other blood transfusion.)
2. As I alluded to in my earlier email, convalescent blood may simply provide a placebo effect. Or in some cases even be harmful. So doctors and scientists are treading very carefully here.
3. It currently looks like convalescent serum needs to be specific to an Ebola species. This assumes all the Ebola species in the US are the same or similar (Zaire, Guinea which is related to Zaire).
4. We can try to synthesize antibodies like in ZMapp, I think (I haven't read up on ZMapp). Isn't ZMapp = monoclonal antibodies? If so, that's problematic.
Plus, generally speaking, synthetic antibodies aren't always as good as the real thing.
5. Convalescent serum therapy is basically passive immunization. We're still working on active immunization, but it currently looks like a long way away.
(4)
DeleteBTW, I should say something about "airborne" which isn't clear in the media or even with the CDC, I don't think:
There are at least two different meanings for a disease being "airborne." First is as a cloud or mist or droplets hanging in the air. And second is as a projectile like sneezing or coughing.
But just because Ebola isn't necessarily contagious via projectiles doesn't necessarily mean it's not contagious via droplets, or vice versa.