Mitigating Shortcuts to Prevent New Disease Fronts

As depicted in fictional movies like Contagion (2011) and Outbreak (1995), new deadly viruses are cropping up via accidental interactions with nature and via purposeful scientific research. Compounded with modern modes of transportation, these deadly diseases have the lethal potential to spread worldwide overnight and become widespread pandemics that wipe out mankind.

Beginning in the last few hundred years, diseases no longer spread via predictable two-dimensional directions. The boundary of where a disease encounters and infects new victims – called the disease front – is now incredibly difficult to map as planes, trains, and automobiles can create new fronts thousands of miles away from an initial outbreak.

Before the 1700s, the size of an infected population did not really matter since the size of any disease front – like a ripple emanating from a single point – was predictable and relatively fixed in size. Because of their slow two-dimensional spread, only the most infectious diseases developed into true epidemics (even the black plague of the 14th century is considered weak as it had a slow three-year spread from southern Italy throughout Europe). Thus if a two-dimensional epidemic happened today, it would be slow and creeping, and public health officials would be able to respond to the well-defined disease front quickly.

Of course, however, modern society no longer allows for simple two-dimensional spreads. The ease and speed of transportation creates shortcuts in which viruses can break into fresh territory and create new disease fronts. Instead of fighting an outbreak in a localized area, viruses can now travel across countries and continents, creating new outbreaks, new victims, and new disease fronts.

For instance, the foot-and-mouth disease outbreak that crippled English cattle farms in 2001 did not have two-dimensional spread although that is what was expected based off how the virus usually spreads: the virus spreads between animals through direct contact, by wind-blown droplets of excrement, or by soil. A two-dimensional spread would have been expected, yet foot-and-mouth disease struck simultaneously on 43 non-neighboring farms. Modern transportation, modern livestock markets, and soil from people’s boots were all shortcuts that allowed the disease to be introduced to new victims, and suddenly animals could be infected anywhere in the nation overnight.

Shortcuts in modern transportation are in essence random, and government officials must create policies that mitigate them in order to effectively stop the spread of an epidemic in its earliest stages. English officials minimized shortcuts by eliminating livestock interaction, preemptively slaughtering nearby cattle farms, and banning travel on countryside roads. Ultimately, the discovery of lethal diseases is inevitable, so we must conduct research to better understand transportation networks and to eliminate shortcuts that will transplant diseases in fresh territory. — Delaney

15 thoughts on “Mitigating Shortcuts to Prevent New Disease Fronts

  1. Delaney’s mention of policymaking as a means of mitigating the effects of rapidly spreading diseases echoes some of the assertions in Jeanne Guillemin’s piece on state-sponsored programs and contemporary bioterrorism. Just as Delaney discusses government officials facing shortcuts in modern transportation, Guillemin notes that “legal and technical restraints, civic awareness, and the decisions of key political actors,” are the means by which biological weapons have been restrained. This relates back to Delaney’s initial assertion that deadly viruses arise via (1) accidental interactions with nature and (2) purposeful scientific research.

    With this in mind, I think it important to evaluate our likelihood/impact model in each of these circumstances. In other words, Guillemin argues “hatreds that dehumanize entire national populations or ethnic or religious groups are as prevalent as ever.” If this is the case, then perhaps the efforts of government officials should go towards alleviating this political discord rather than researching and changing policies regarding transportation networks. On the other hand, if the likelihood and impact of natural diseases such as the foot-and-mouth disease Delaney mentions or other “accidental interactions with nature” are a greater cause of concern, then policymaking efforts should take that into account.

  2. Advancements in transportation have led us to be able to travel with great speed and ease. The world is more connected than it has ever been. While this is fantastic in the sense that ideas and values can now be more easily communicated between cultures, by the same token, bacteria, viruses, and parasites can be as well.

    This is particularly evident in both the movie Contagion and the game Plague. In Contagion, after Claire Danes’s character contracts the disease, in a mere 24 hour return trip home, she make a stop at another city and interacts with dozens of people—leaving a trail of future quarantines in her path. Similarly in Plague, the more advanced and densely populated countries continually have planes and ships leaving them—each with the potential to spread the disease to their destination.

    And though our medical technology has advanced as well, this leaves people infected with the disease living longer and interacting with more people than they would have in earlier times. In this sense, over time, we have artificially increased the R_0 of every disease coming our way…

    As we can see in “When Zombies Attack!”, a high R_0 can spell trouble for the world’s population and allow the disease to get out of hand fairly quickly. Thus, in this day and age, we need to be more vigilant than ever and be ready to identity a potential outbreak and take the necessary precautions to reduce its spread at a moment’s notice.

  3. I agree with the facts presented in this post about the challenges an interconnected society poses towards controlling the spread of diseases. However, I question what the policy focus should be. There should definitely be safeguards in place to help limit the spread of diseases once they become known, especially when those diseases solely affect non-humans. However, difficulties arise when restricting the travel of human beings, and a high bar must be met to justify a quarantine against an individuals will. Additionally, the idea of posing preemptive restrictions prior to any disease’s existence sounds questionable at best and potentially liberty-restricting.

    The rapid spread of diseases is a real threat that is more relevant than ever. However, it also comes with a host of difficult practical and moral questions. Hopefully legislators can begin to think them through and come up with a fair and effective system.

  4. I believe Delaney’s discussion of two-dimensional and three-dimensional spreads fits quite well with the fascinating example of Ebola in the late 1900s. Despite the recent timing of these outbreaks, they nonetheless displayed a two-dimensional spread, a result of the fact that while much of the world has acquired modern networks of transportation, sub-Saharan Africa lags behind. With a lack of such transportation shortcuts, the outbreaks were unable to reach densely populated areas.

    An additional factor was the lethality of Ebola. “Ebola’s tremendous violence,” writes Watt, “is also its one weakness: it is literally too deadly for its own good” (pg. 163). Though infectious, Ebola is not efficient. What this means is that its victims die before the disease has had a chance to search for new ones. In a similar vein, the nature of Ebola’s symptoms also has a counterintuitive effect on its ability to take on a three-dimensional spread. The severity of the symptoms forces victims to immediately be hospitalized and quarantined. Once again, a trait that makes the disease so frightening actually simultaneously makes it easier to contain. In the African context, the outbreaks were not allowed to pass the confines of remote villages in large part because of the need for rapid hospitalization.

    In conclusion, while Delaney does a great job explaining the impact of modern transportation, aspects specific to a particular disease also greatly impact dimensionality. In the case of Ebola, its terrifying symptoms and general inefficiency made it a more easily contained disease in an already transportation-deficient context.

  5. Delaney’s concerns about the modern change from a historical two-dimensional spread of disease to a three-dimensional spread are warranted. I share her concerns, and want to reemphasize the potential for an increased rate of the spread of disease caused by globalization and the modernization of transportation. The potential potency of modern transportation has already been seen in the recent spread of both Ebola and Zika. Ebola was spread to different countries by people traveling on planes. Zika has also been spread by travelers who then contaminate their local mosquito populations. I agree with Delaney in that the need for increased and improved regulations to hinder the spread of disease need to be implemented, although I sympathize with policymakers who must balance the distant and intangible possibility of a pandemic with the immediate losses to productivity and wages that increased regulations may cause.

    Although I share Delaney’s concerns regarding the three-dimensional spread of disease, I feel that, practically, it will be difficult to do much to avoid a three-dimensional spread. My biggest concern is the rise of superbugs, which are drug-resistant strains of bacteria caused by “overuse of antibiotics in humans and livestock.” The rise of superbugs and a three-dimensional spread of disease go hand in hand because a three-dimensional spread of disease yields superbugs more potent. However, I think that there is a greater likelihood of reducing the threat posed by superbugs than in preventing a three-dimensional spread. But, policymakers need to take action.

    Yesterday, the World Health Organization warned that “a dozen antibiotic-resistant “superbugs” pose an enormous threat to human health.” WHO also contended that many superbugs may be just as dangerous as viruses such as Ebola and Zika. The New York Times reports that superbugs kill 25,000 Europeans and 23,000 Americans a year, and that, although most of these deaths are in elderly populations, more and more young and healthy people are dying from these bacteria. This increasing threat of superbugs makes the need for a policy response more pressing. Governments need to increase public funding for research to create effective antibiotics to fight superbugs—because of a failure of the private market—and to improve collaboration between doctors and veterinarians—because of drug resistance that arises in animals can spread to humans.

  6. At the beginning of the semester, we discussed the implications of new technology. While new technology makes life easier, in this case through access to worldwide travel in less than twenty-four hours, it also poses threats. With further development, whether it be in the cyber sphere, related to biotechnology, or the ease of transportation, comes both more benefits and risks. At this point, the issue becomes how to handle the risk portion of this equation.

    Humans cannot live in fear. Fear causes limited research, development, and/or simply not living normal everyday life. The problem posed in Delaney’s post regarding a disease outbreak crippling livestock is the perfect example of this. People will not halt all activity to stop the spread of a pathogen—especially if they do not think or realize that they could be potential vectors. This leaves government policies and actions as the best defense against an unpredictable and fast disease front.

    Our guest speaker today, Andy Leifer, spoke to this idea. He shared the view that the best way to counter bio-threats, whether nature or terrorist-based, is to plan ahead and if possible, have stockpiles and vaccines. In cases where the pathogen is spread through means other than human contact, the best policy action would be to shut down any activity that could contribute to further spread. However, as I mentioned, this is extremely difficult, because people are not always willing. If there can be a preventative measure taken before arriving at this point, then that is the route to go.

  7. Delaney makes an interesting point on the threat of pandemic; namely that advances in transportation technology create shortcuts for the spread of infectious disease. In the movie Contagion, infected persons traveling at high speed spread the disease more quickly than ever could have been accomplished in the past. For example, as was mentioned in class, even the black plague was relatively slow-moving taking years to cross Europe. Transportation is indeed the third dimension for the spread of infectious disease in the modern era. However, it is almost impossible to consider a proactive or preventative government policy that could mitigate these shortcuts.
    The government cannot prevent people from traveling unless they were to have a confirmed case of a highly contagious disease. Most likely, any suggestion for a medical check in airports or train stations would fall on deaf ears as the steps in involved would be too expensive and troublesome. Moreover, transportation is gravitating towards a more personal level — with self-driving cars on the horizon, it is hard to imagine the government managing where people go and come. The best the government could do would be to recognize certain traffic patterns in case of outbreak and step in to prevent it from progressing any further. This is a defensive policy but if the government knew exactly which planes and roads to shut down in case of extreme emergency, perhaps it could help.

  8. Delaney argues for the necessity to understand how diseases can spread to better prevent them. Some immediate concerns, however, come to mind given this suggestion and I am, like Zach in an above comment, unsure that this should be a major policy focus. My first concern is that all diseases spread different. Biologically, no two diseases are the same; And even if there are equivalents, the agents involved in the ecology of each disease may differ. Given these differences it seems unproductive to attempt to detail the spread of all diseases. Moreover, modeling the spread of a disease is not simple. In many cases assumptions must be made in theory that do not apply in actuality and the diversity of contexts of equivalent diseases must also be taken into consideration. Furthermore, often times the model is constructed after the fact of the spread of a disease, when it is too late. In the 2014 West Africa Ebola outbreak, for example, the epidemic started in December 2013 but it took the WHO months to notice the spread of the disease (only after a US citizen traveling back from Liberia was diagnoses) and nearly a year to devise and implement a road map for the containment and control of the epidemic – by then deaths were already on the rise. Even in the 2015 Zika virus epidemic today, public health response has been slow and the disease is still spreading. These examples do not argue against research to understand diseases and how they spread, but highlight the necessity of immediate action rather than theory when it comes to fast moving diseases in our “interconnected world”.

  9. While I agree with Lisa’s point that there is an immediate need for actions reforming key elements of our global defense against pandemics, I would caution primarily focusing on just current disease outbreaks and their immediate response mechanisms. Accounting for and combating the spread of future contagious pathogens must be a multifold approach and include the types of analyses of global transportation systems Delaney calls for in her argument while addressing immediate functional concerns like streamlining rapid response processes for our world health institutions. Indeed, while it Is true that not all diseases travel in the same way, some of the most contagious or threatening to humans could currently move with relative ease between cities, states, and regions through our complex systems of shortcuts in modern day transportation.

    In his article, Kilbourne himself argues that “Pandemics, if they occur, will be primarily from respiratory tract pathogens capable of airborne spread.” This would indicate the viability of contagious individuals and contagions themselves spreading a pandemic throughout the global transit system and moving across borders through planes, trains, and ships. What’s more, the rapid urbanization and greater reliance on public transportation by billions worldwide indicate that modeling the potential spread of disease even within an urban transit system could be critical to any future effort to combat a potential pandemic. Preemptively modeling transportation networks, although not nearly as exact enough to predict a new disease’s spread, can provide an invaluable opportunity to understand current gaps that some of the most dangerous diseases known could use to potential spread worldwide.

  10. Modern transportation reminds me of the concept of a “grey ball” of technology that has both benefits and risks associated with it. On one hand, it allows people to efficiently travel massive distances. On the other hand, it also allows diseases do do the same. As Delaney mentioned, modeling the spread of a disease is much more difficult now due to modern transportation and presents the risk that we will not be able to properly assess the spread of a massive outbreak quickly enough to stop it from inflicting massive damage to the global population.

    In terms of a solution, while it would be great to monitor everyone’s health and be able to limit the travel of people who are infected, it is exceedingly difficult and attempting to do so would likely drastically reduce the efficiency of modern transportation. Biological threats are simply very difficult to monitor since these threats are microscopic, naked to the human eye. Overall, it is worrying that the efficiency of transportation methods seems to be out-scaling our ability to properly monitor threats associated with this growth in technology. Perhaps the only way to address these issues is to create a stockpile of vaccines and address the issue ex-post.

  11. I agree with Delaney’s argument that conducting additional research to better understand transportation and other methods of transmission of bioweapons would help us protect our society.

    One reading that particularly stood out to me was the piece on bio-terrorism. In it, Jeanne Guillemin argues that “the world is much different now from what it was for most of the twentieth century, when it was easier for Americans to retreat from global issues” (Guillemin 18). I would argue that the United States should be the leader in creating new technologies and preventative measures to protect against the spread of communicable disease. The United States, as Guillemin asserts, should definitely emphasize the importance of improving surveillance of transportation systems as well as surveillance of major facilities where bioweapons could be produced or stolen.

    It was interesting to examine the Ebola and H1N1 outbreaks, to see the differences in public health responses. The swine flu outbreak, which is mentioned in the movie Contagion, prompted an apparent overreaction on behalf of the Center for Disease Control. As Lisa mentioned, the Ebola virus did not receive immediate attention when it should have. It is, in my opinion, better to overreact rather than under-react to an outbreak situation. Therefore, governments should make efforts to detect and take outbreaks more seriously in the future.

  12. “If a two-dimensional epidemic happened today, it would be slow and creeping, and public health officials would be able to respond to the well-defined disease front quickly.”

    I think another counterfactual is also worth discussing. If one an epidemic that spread in three dimensions happened before the 1700s, the impact would be unimaginably worse than one today. That is, Delaney is correct that epidemics have become more intense and complicated in the way that they spread, but that doesn’t mean that the world is necessarily less equipped to deal with it.

    Our mapping technology has substantially improved. Mathematical modeling can map random walks in ways that may not mirror the spread of people carrying an infection precisely, but come far closer to it than our predecessors. Investment in and development of diagnostic tools such as BioWatch and APDS (Autonomous Pathogen Detection System), both detailed in Nouri and Chyba (2008) help us become aware of epidemics early enough to (hopefully) stop them before they reach drastic size. The rise in “start-up” style DIY biology labs as profiled in Ledford (2010) applies a private sector, innovation-heavy approach to life science. While there may be risks involved, there’s also the potential for a scientific breakthrough that revolutionizes our response to biological threats. And while globalization and travel helps pathogens spread quickly, it also allows information about staying safe to spread quickly and for vaccines, antibiotics, antivirals, or other containment mechanisms to be spread and distributed quickly. Andy Leifer made a great point in his lecture today: epidemics don’t stop at the U.S.-Mexico or U.S.-Canada border. More interconnectedness also allows for governments to coordinate the responses of their public health agencies.

    All this goes to say that while “Contagion” certainly gave me goosebumps, I know that it was fictional. And even still, the epidemic was stopped, the source became known, and the appropriate measures were taken (albeit not before significant loss of life). I don’t think that could have been possible years ago.

  13. What does it mean to study transportation systems more closely so that we can better prevent the spread of disease, as Delaney suggested in her post? The reference to the two-dimensional (and now, multi-dimensional) spread of disease makes it obvious that epidemics are becoming harder to control because of the complexity of modern transportation systems. But as the movie ‘Contagion’ (and to a degree, the aftermath of the Boston Marathon Bombing) show, it’s harder to counteract the spread of epidemics even if we know how it travels. This is because there is a lag between the detection of a disease and its treatment and panic will cause humans to run around and spread the disease, even if that’s worse than staying put.

    Take for example, the video games that we had been discussing in lecture as well as the BioWatch and APDS tools mentioned in the Nouri and Chyba reading. Sure, we get a better understanding of the channels through which the disease spreads but it would be difficult to stop the disease in its tracks before at least a substantial amount of lives are lost, unless we can increase the reasonably tie the spread of infectious diseases to the spread of medicines and vaccines. This is an argument similar to what Lisa Li wrote – it took months to detect the spread of West African Ebola virus, so we really model paths for medicine to spread so much more than spread of disease. So public policies, in that case, would have to focus on inter-governmental cooperation to coordinate the dispersal of medicine along paths where an epidemic might have spread.

  14. Just to clarify my statement above: I mean that it’s important also to consider who medicine is spread, and try to make it just as quick as the spread of the disease. Otherwise, treatment will move at a slower rate than fatalities. So perhaps the best way to preempt bio-terrorism is by pre-stocking vaccines at hospitals? But if so, then you’d have to know what’s being released and its biological makeup so your vaccine can be effective. Kind of a quagmire.

  15. Reading through these comments and the blog post, I’m reminded of a famous phrase from history, “the bomber will always get through.” It seems that we’re talking about pandemics and the spread of disease with a sense of inevitability. Delaney’s blog post painted a pretty grim picture about our ability to prevent diseases spreading through this “third dimension” of communication. Adding to her argument, my classmate Richard Choi wrote about our inability to successfully model the outbreak of a disease with the addition of that third dimension, and the deleterious effects that would have on public health. But that grim future need not be the case.

    As we talked about in lecture yesterday, it’s possible to take policy measures to safeguard against disease outbreaks, if not prevent them altogether. The CDC, for instance, maintains the Strategic National Stockpile of pharmaceuticals and other medical supplies in the event of a major disease outbreak. Kilbourne describes in “Plagues and Pandemics: Past, Present, and Future,” how pandemics can be blunted by the adequate distribution of vaccines. He also argues that most disease agents can be controlled with the resources we currently have available. There is not a consensus that a pandemic would be as scary as shown in Contagion, or even to the heights of hysteria seen in the real world during the Ebola outbreak.

    In short, don’t panic.

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