The idea of stopping flu "at the border" has received almost uniformly bad reviews from public health experts. Once human to human transmission starts we won't be able to stop it by closing our borders, although we likely will cause the usual unintended consequences, like preventing vital personnel and supplies from getting to where we need them. At least if we do it in the usual ham handed way this administration is famous for. We learn via CIDRAP News that federal officials are still willing to give a "risk-based border strategy" (RBBS) a go, at least in the form of an exercise. Now, at least, the objective is vastly scaled down. It is just to slow spread enough to give a little extra time to prepare and "educate" the public:
Officials from several agencies recently converged on Miami's international airport to take part in a full-scale exercise of the federal government's risk-based strategy to slow the spread of a future pandemic influenza virus across US borders.
Christine Pearson, a spokeswoman for the US Department of Health and Human Services (HHS), attended the first day of the 2-day drill on Nov 5 and told CIDRAP News that, unlike previous tabletop discussions to test the risk-based border strategy (RBBS), the exercise at Miami included a real plane and actors who played the role of passengers in an airport setting.
"It provided a level of realism that we hadn't had in past exercises, which had mostly been facilitated discussions," she said.
The RBBS is a short-term strategy that the federal government will use in the initial states of a pandemic to delay the spread of the virus enough to afford officials a little extra time to educate the public on how to protect themselves from the disease, produce and distribute vaccine, and position medication and supplies, Pearson said. The strategy involves screening international air passengers to gauge if they are sick or have potentially been exposed to others who are sick with the pandemic virus.
The system would begin when it's clear that a pandemic influenza virus is spreading globally and would end as soon as the virus begins causing illnesses in the United States. (Lisa Schnirring, CIDRAP News)
Ideas like this often sound good at first but often don't survive closer scrutiny. The idea is to turn on the RBBS fast enough and uniformly enough (essentially at all the important international airports) that it can delay the pandemic seed from sprouting within US borders but not any longer so that it doesn't begin to become a hindrance rather than a help. What is likely is that the system will be too slow to start, not cover everything it needs to and too slow to stop. Once you put in place a mechanism for limiting travel and movement, local jurisdictions will be very reluctant to abandon it.
That's if it works. In fact we have no idea whether a system like that would have any meaningful slowing effect, or if it did, for how long. We know we can slow travel and the movement of goods and services. That part is certain. So there is a significant downside without a good fix on the upside.
Everyone will have their own ideas about this, of course. My view is that this is somewhere we shouldn't go. That's my version of travel restrictions for flu.
I basically agree with you revere, especially for 'normal' influenza. If the next pandemic is truly with a virus that has a 60% or higher case fatality rate the equation could change. If more people get very sick and more immobilized earlier this could magnify the effect of movement restrictions. I don't think we have a real clear handle on what the true prodromal stage of this disease is like.
Arent there other measures that could be done to reduce transmission in airports? Masks, hand sterilizers, HEPA filters, UV in air ducts, even Tyvek suits would cut it down a lot.
If you gave people a UV opaque 100% coverage Tyvek suit and a respirator with a HEPA filter, you could irradiate the airport commons area with sterilizing levels of UV while people were still in it. That would cost maybe $10 per person per flight.
You would have to stop some practices, such as restaurants and in flight food and drink. Giving out MREs and water in UV opaque containers would still be pretty cheap. An air-lock style opening to allow people to eat wouldnt be that difficult.
If you made restrooms single stalls with even more powerful UV lights, to sterilize everything in a couple of minutes, people could safely get out of their suits to do their business.
You could implement people wearing these isolation suits now. Avoiding getting the flu or even a cold might be worth the hassle and the $20 cost to some individuals, and even without the external UV irradiation an isolation suit would cut down transmission a lot, in both directions.
I completely agree that trying to shut down transportation isn't going to be effective. The exact people you are trying to stop are the ones most likely to try and hide their status and fly anyway. With isolation suits there is much less of a problem.
The impediment to implementing it is that suits will frighten people until they get used to them.
The impediment to implementing it is that suits will frighten people until they get used to them.
Posted by: daedalus2u | November 14, 2008 5:24 PM [kill][hide comment]
Another is that a five-hour flight is a long time to be wearing a Tyvek isolation suit, particularly for people who may become symptomatic en route.
Plus, a lot of flyers suffer incredible stress just getting onto an airplane; an isolation suit would push some of 'em right over the edge, IMO. It's not rational, granted, but then, neither are human beings.
daedalus: I must have misunderstood you. It sounded like you were suggesting we put everyone who flies into a US int'l airport in a Tyvek space suit. Think about this. If you put in place any kind of barriers to travel, you will be late putting them in and for sure late removing them. Meanwhile you will have barriers to travel, with all that entails. And you likely won't make a dent in spread of the flu.
I think that if the alternative is shutting down air transport, people could learn to tolerate a whole lot. In the start of a pandemic, I doubt that people who get really stressed from flying are going to be flying. If people know that wearing a suit is what it takes to be allowed to fly, either they will wear suits or not fly.
There will probably be a tremendous reduction in flying.
Something like this would reduce the transmission of any disease, even things like smallpox and TB.
It would be cheaper and more effective than shutting down the airports.
daedalus: But that's not the alternative. We aren't going to do that. Everyone agrees that's a non starter. This is trhying to save the appearance of that but not do it. It's "bird flu theater," like taking off your shoes at the airport. Useless and counterproductive.
Also if the transmission pattern evolves more slowly and becomes more similar to say various hemorrhagic fever viruses (which have similar case fatality rates) various movement restriction and isolation strategies may have more impact.
I think you and I are in pretty much agreement that there are better alternatives than shutting down the airports or putting everyone in an isolation suit. Unfortunately we are not the ones choosing between alternatives.
The whole point of your post was that those currently in charge of planning for pandemics are considering shutting down the airports. They are not just considering it, they are actually implementing it.
They are not going to abandon their implementation unless there is a "better" alternative that they understand as being "better". The isolation suit idea is "better" in that it is cheaper and in the bureaucrats' mentality more effective than shutting down the airports.
Those planning to shut down the airports don't have the ability to understand that it would be ineffective. A way to deal with the mindset of those currently in charge of planning for pandemics is to give them a "better" alternative, let that sink in until they have abandoned their first bad idea. Then give them an alternative that is "better" still.
revere, everyone does *not* agree that travel restrictions wouldn't work. Me for example. First, let me be clear on what I'm saying: stopping infected people from entering an area without infections would be 100% effective in preventing infections in the restricted area. This is a simple statement of fact. Humans will be the vector in a pandemic. Stop the vector from moving, stop the pandemic. There is really nothing to debate on this issue.
The real questions is whether it is possible to restrict people from moving, not whether this would work if successfully applied. On this issue, I would suggest that the public health officials who have been opining on this are completely unqualified to give their judgments. The experts on movement restrictions are the military, not MDs. Let's ask the Commander of NORTHCOM whether he could prevent movement of people into North America if given the order from the POTUS. Note, in the event of a mild pandemic, such a draconian action would probably not be taken. However, if H5N1 went pandemic at its current CFR, closing all airports and seaports to North America would be the only rational approach. If local outbreaks had already occurred, they could be stamped out with internal movement restrictions.
There is substantial empirical evidence that movement restrictions can be effective in preventing the spread of influenza during a pandemic. This is more fully discussed here.
Mono: With all due respect, I did not include you in the "public health officials" community. I never said "everyone." Secondly, there is not just the question of feasibility, although our borders are porous as everyone knows. But the big question that has been raised is the collateral damage, stopping things we don't want to stop (like key personnel, supplies, resources, not to mention the economic damage). The idea of using the military to seal the country also gets uniformly dismal reviews, whatever you may think of it. And as the immigration problem shows, isn't feasible.
Revere, Mono is exactly illustrating my point. It isn't those with public health expertise who will make the decision to implement closing airports, it is the same public officials who are trying to do exactly the same thing with the war on drugs and who will achieve exactly the same results with a "war on flu" (or more accurately a war on people infected with flu).
If all aircraft approaching US borders were shot down, flu would not arrive via an aircraft. The cost of such an approach would be horrific and unacceptable independent of how effective (or not) it would be. Those in charge of the war on drugs are not capable of appreciating or acknowledging that it is a failure. We would hear "you are doing a heck-of-a-job".
My thought was if you do put everyone in an isolation suit, you can let them fly with essentially no other restrictions even when a pandemic is raging. If you implemented UV lights in airports, you would have a mechanism to decontaminate airports (to some extent) even if you did nothing else. You evacuate and crank up the UV.
To turn on the UV while people are present you have to have 100% compliance with wearing a UV blocking suit. People could wear isolation suits right now. I am sure there are some who might do it any way (such as Michael Jackson).
The biggest cost to stopping air travel is the lost revenue for the airlines, followed by alternate accommodations for stranded passengers. A disposable isolation suit is cheap compared to the cost of a flight and cheap compared to the cost of a hotel room for a single night. If people can't fly they will drive, take the train, boats, or walk, and they will do so without wearing an isolation suit.
Because the cost of this approach is small, it can be triggered with a lower threshold. A false alarm doesn't cost very much, $20 on top of a $500 airline ticket is smaller than the cost of a hotel room for a night.
The average number of US airline passengers per day is a couple million. $50 million per day seems pretty cheap to me (2.5 million suits times $20 per suit). You could even have a few trial runs, well announced and have everyone wear the Tyvek suits to get a feel for what they are like. Passenger airline revenues for a year are about $100 billion.
The cost of the alternative approach, stopping all air traffic would leave ~ 1 million stranded. Lodging those individuals at ~$100 per day would be ~$100 million per day. Lost revenues would be ~$300 million per day.
revere, it is certainly true that I am not in the PH community. However, I am a scientist and can read the relevant literature. The empirical data is clear: movement restrictions work.
The "borders are porous" argument is incorrect when applied to islands. As I'm sure you know, American Samoa completely escaped in the flu pandemic in 1918 through rigorous application of movement restrictions. There is absolutely no reason why modern island nations could not apply the same strategy with the same success today. They would simply have to add airports to the list of transportation to shut down.
Perhaps you didn't notice, but I suggested applying movement restrictions to North America, not the US. North America includes Canada, the US, Mexico and the "Central American" countries. All geographical continents are islands and hence, isolation would only require shutting down air and sea transport, not ground transport. Thus, your immigration example is not relevant.
When you say using the military gets "uniformly dismal reviews", I assume you are once again only counting those in public health. Have you considered that possibility that they are not the only ones who should be allowed to have an opinion on this subject? Or even more radically, that the public health establishment has done a terrible job of preparing the public and ought not to be the decision-makers in the pre-pandemic period?
daedalus, would you mind stating your assumption about the CFR of the pandemic your tyvek suit plan would apply to? I think sometimes people in flublogia talk past each other because they are working under different assumptions. For example, if H5N1 went pandemic with its current CFR, do you really think the lost cost of air travel would relevant? A pandemic of this severity, left unchecked by movement restrictions, would kill billions and would likely reduce most of the world to a stone age existence.
I do agree that some essential goods would need to move even during a very severe pandemic. I also agree that the proper use of PPE could make this transport relatively safe. But who is trained in the logistics of transporting large amounts of goods while protecting themselves against lethal biological agents? Only one group comes to mind: the military.
Mono: When Bush suggested it he got creamed in the general media. It wasn't just public health. You are entitled to you opinion, but those who have studied it (North America is not Samoa or Australia) have concluded it is unworkable. The exercise that is the subject of the post doesn't even assume it will work more than producing an unspecified and unknown amount of "slowing." Meanwhile shutting it off will be difficult in many places and the collateral damage of restricting travel will have been done. Let me ask you further: if it arrives in San Francisco, do you advocate cutting off travel from SFO? And how are you going to get Mexico and Central America and Canada to go along with this?
revere, I'm not sure President Bush got "creamed" in the general media for suggesting quarantining cities in the event of a pandemic, most didn't even seem to notice it. In any case, I don't really care what the general media says, how about, instead, asking the general public? Further, President Bush did not propose closing air and sea ports to North America, he suggested a cordon sanitaire around American cities after letting the virus into the country. AFAIK, that is still the plan today, they just aren't publicising it.
If we keep the virus out of North America, internal movement restrictions will not be necessary. Further, I am opposed to plans for internal movement restrictions without sufficient supplies for those in the restricted zone. This can be accomplished by an extensive public education campaign on the need for family self-sufficiency and by government stockpiling of food, medicine and other necessary goods for the mega-cities. Everyone should know that they will be required to remain in their homes if a highly lethal, highly contagious virus is spreading in their community. If you explain ahead of time why this is necessary and people and communities are prepared, I think compliance will be high whether we are talking about San Francisco or any other city.
The key to convincing the governments of Mexico and Canada to cooperate is simply to tell them the truth: H5N1 may go pandemic with its current CFR and in this eventuality the only strategy that will save their countries from complete disaster will be to shut down air and seaports until an effective vaccine is ready.
Mono, I think the isolation suit idea would be better than trying to shut down air traffic. There are better ideas. Ramping up public health so that there are not tens of millions without health care would enormously increase the surge capacity of the US health care system and would provide other benefits too.
The problem with putting the military in charge of shutting down air traffic is that the one way they know how to do things (with military force) isnt the proper way to deal with panicked civilians unless you are willing to tolerate a lot of civilian deaths and destruction of airports and aircraft. I am not willing to tolerate that.
People might panic if they have to wear isolation suits. Being in charge of your own safety by making sure your own isolation suit is in order would likely be more calming than worrying about whether foreign looking people have the flu or not.
The seriousness of a pandemic flu outbreak wont be known until after it happens. Any successful mitigation measures will have to be implemented before it is known how serious the pandemic is (or even if there will be one). Under those circumstances the cost matters a lot.
It is completely unrealistic to plan as if complete exclusion of flu from all of North America is possible. It isnt. Birds can carry this flu too.
If a pandemic does start, air travel will decline enormously no matter what the death rate is. The best thing that can be hoped for is a slowing of the spread while maintaining vital supply lines and getting supplies to where they need to be. That requires air transport. Air transport requires airports to stay open and to be manned by airport personnel. That requires a graceful shut-down of passenger travel while maintaining airports open and aircraft flying as they shift from carrying passengers to freight.
Mono, daedalus: I find myself in fundamental disagreement with you both. I judge attempts to keep the virus out once it is easily transmissible to be fruitless and counterproductive and all efforts should be bent toward managing the consequences. Mono, you and I remember history differently. I don't think there is much left to say.
daedalus, if the CFR remains high, that will be apparent quite quickly. The exact percentage will not be important.
The military will not give the order to shut airports down, this will be decided by the POTUS.
Imo, only the military can effectively maintain transport while following strict biosafety procedures. Does anyone seriously think the CDC could manage this?
revere, I understand that you have fundamental philosophical objections to movement restrictions. However, the choice is not between movement restrictions or no movement restrictions. In the event of a high CFR pandemic, there *will* be movement restrictions no matter what the public health establishment decides. In the absence of a carefully though out plan for movement restrictions with public participation, here is what will happen, imo: Airports will be left open until enough infected have entered some cities and caused large local outbreaks. Once the public sees cities in flames, they will demand the airports be closed. This will be too late for many countries. Next, states and cities without infections will unilaterally impose their own movement restrictions in an attempt to keep the virus out, regardless of what the federal government does. The ruthlessness of these attempts will vary in direct proportion to the CFR. Finally, there will be terrified men with shotguns manning roadblocks in rural areas who will blast at anyone who tries to enter their area. In short, it will be an unholy mess of fear, desperation and bloodshed.
In contrast, if movement restrictions are discussed openly, instead of behind closed doors as they are now, civil liberties could be maximized and the risk of misunderstandings could be avoided.
There are really two choices: live a pretend world where people will behave as you wish them to or live in the real world where you deal with people as they are. The first choice always leads to tragedy.
Mono: No, you don't understand. Muy objection to movement restrictions is not philosophical. It is practical. I believe they will backfire and make things worse, not better. That is what most public health people think, too. Air travel will be vastly curtailed in the event of a high CFR pandemic because people won't be traveling. That is the reason schools and businesses will be closed, too. They won't close under gov't order but by themselves. But trying to shut down airports will create a serious situation where it will become difficult to move the things that need to be moved.
My objections are not philosophical. You do not understand what I have been saying.
There are some very scary and seriously dangerous ideas being put forward in this comment tread. If there is a general global pandemic no group the size of a continent is going to keep it out for any significant time however much they want to. Smallish islands yes but N. America or Africa I think not.
If the pandemic is severe it is difficult to see who is going to want to fly, unless they are just trying to get home. Any attempt to seal ports or land boarders would be catastrophic. Nowhere is isolated in terms of trade these days and any item you consume will have a component or raw material that came from abroad even if it was only the fuel that delivered it. The conveyer for global trade is an extremely efficient system with most goods moved buy bulk carrier or container but it can not be stopped. There are nodes through which all this cargo passes but they are not designed for storage they are trans-shipment points with limited holding capacity. If you mess with this conveyer you will cause a global economic meltdown magnitudes larger than our current problems, even in the absence of a pandemic. If you have seen the time it takes to clear the backlog after a couple of days baggage handlers strike at one airport you will begin to appreciate what the simultaneous closure of all container ports worldwide might do. Off course these containers hold perishable foods, medicines, essential spares etc. Any manufacturing enterprise is putting items onto and picking items off it, if it halts so must they soon afterwards.
I dont care much about the planes as they shift less but from a practical point what if a symptom of the pandemic is sudden symptom onset. Modern commercial air craft usually have two pilots who take many precautions to prevent simultaneous illness cant eat the same meal etc. The practicality of guaranteeing this on a long haul flight may make airlines unwilling to take the risk or more accurately may make their underwriters unwilling to take the risk.
revere, what is your rationale and or evidence for saying that movement restrictions will backfire? I have provided specific examples of how they worked.
JJackson, I agree that globalisation makes movement restrictions much more difficult, which is one reason I would like to see it destroyed. Part of pandemic preparedness should include national self-sufficiency for critical goods like food, medicine etc. Any nation which depends on imports for the continued existence of its citizens has put their lives at risk in any sort of major catastrophe.
As regards the economic consequences of globalisation, that is another topic, but suffice it to say that I think this process has been the most destructive economic policy in human history and may end up causing the loss of a substantial percentage of the human species.
Monotreme, could you please provide links to or titles of the peer-reviewed sources which have led you to conclude that border-closings would be effective in the U.S.?
I hear your opinion loud and clear, but I do not know on what it is based.
Revere, I dont think that trying to keep flu out once it becomes easily transmissible is feasible either. My (off the cuff) suggestion is to slow the transmission (perhaps), and to preempt a draconian military interdiction course that will be the natural response of Bush era holdovers during the first few days of any pandemic and also to perhaps forestall panic by people away from home and xenophobia toward those who are from wherever the pandemic starts, and to try and prevent the disruptions that will prevent the effective actions needed during those first few days.
If there is a pandemic people are going to become even nuttier than they already are. Isolation suits may become things to kill for (no matter how good or useless they actually are). Having a vast supply of them may save lives not by preventing transmission but by preventing panic.
Now that we have a president elect who seems willing to try and do the right things, not simply induce panic, perhaps a rational approach can be implemented.
In no way do I think this substitutes for the kind of distributed upgrade of the public health infrastructure that public health experts are suggesting. I think at least 100 times more should be spent on that than should be spent on any airport isolation-type stuff.
anon, I provide a link to compendium of empirical evidence supporting the effectiveness of movement restrictions above. Here it is again:
Links to a variety of sources related to the effectiveness of movement restrictions can be found at that page.
Below is the list of references from which I quote:
McLeod et al. (2008) Protective Effect of Maritime Quarantine in South Pacific Jurisdictions, 1918-19 Influenza Pandemic. Emerg Infect Dis. March.
The Center for the History of Medicine (CHM). University of Michigan Medical School. The 1918-1920 Influenza Pandemic Escape Community Digital Document Archive.
Brownstein et al. (2006) Empirical Evidence for the Effect of Airline Travel on Inter-Regional Influenza Spread in the United States. PLoS Medicine. 3:e401.
Rambaut et al. (2008) The genomic and epidemiological dynamics of human influenza A virus. Nature.
Russell et al. (2008) The Global Circulation of Seasonal Influenza A (H3N2) Viruses. Science.
the whole difference is that revere and monotreme are assuming a pandemic with different mortality rates.
There is a threshold, where movement restrictions
make sense and they can be effective if seriously
implemented, but very expensive, so typically people
refuse thinking about it.
It did work in wartimes, except airplanes,submarines etc.
which should not be a problem in a pandemic when
countries cooperate. There is no motivation to break
And if it happens, then there is a surveillance machinery
as with SARS and quarantines at lower levels
I was not very happy with my earlier post as it was too dogmatic without much explanation. It prompted me to write in a bit more on the Global Conveyor of goods which I posted at FluTrackers - as it was also relevant to something I had written there. Anyway for anyone still interested http://www.flutrackers.com/forum/showthread.php?t=86932