It sounds simple, like canceling a party: Cancel the 2016 Summer Olympics to prevent further spread of the Zika epidemic. Some in medicine and public health have lobbied and even petitioned for this action. Yes, the Zika epidemic is a major public health emergency. Yes, the virus may lead to birth defects and nervous system disorders. Yes, the location of the Olympics (Rio de Janeiro) is in Brazil, which has been the epicenter of the Zika epidemic. But is canceling the Olympics really the answer? Or would such an action distract from what really should be done? What's the evidence behind the calls for cancellation? Could canceling the Olympics actually do more harm than good?
Here's the argument that has been offered for canceling the Summer Games. This mass gathering of athletes, officials and tourists in the country hit hardest by Zika may provide mosquitoes carrying the Zika virus to bite and transmit the virus to many people from different countries. On top of that, people from different countries may pass the virus to each other through sex. (Yes, people have sex at the Olympics. ESPN offered an account about how much sex (a lot) occurs among athletes at the Games.) Then, after the Olympics, the infected people may return to their countries where they will further transmit the virus to their country mates via sexual contact or mosquito bites.
Although these are legitimate possibilities, the question is how much more Zika transmission may occur with the Olympics, and what would be the real benefit of canceling the Olympics? Rio is very large city that serves as a business and travel hub for many. People continue to travel to and from Rio every day. It's not as if they would shut down Rio along with canceling the Summer Games. Therefore, transmission is continuing and would continue to occur with or without the Olympics.
The answer is no one knows yet what impact cancellation of the Olympics would have. Before making any claims or decisions, we need more appropriate studies. We just don't have the same evidence, data and information that we had for some past epidemics such as the 2009 influenza pandemic. Where are the clinical, epidemiological and computational modeling studies? Prior to and during the 2009 pandemic, different people were calling for various policies and interventions to reduce the spread of influenza. But computational simulation models developed by various teams showed that some of these interventions would not be worth the cost and could even have unintended consequences.
Let's take the example of closing schools to prevent the spread of influenza since school children are aggressive spreaders of influenza. They rub their hands and faces and other parts of the body, don't wash their hands, and rub their grimy mitts everywhere, such as on door knobs, clothes, desks and each other. Kids are essentially mobile petri dishes. Therefore, the rationale was that shutting down schools would prevent these little bug farms from passing the flu to each other and then going home and getting their families sick.
Sounds reasonable, right? Well, it's not that simple. Our team, which included Dr. Shawn Brown of the Pittsburgh Supercomputing Center/Carnegie Mellon University and Phil Cooley and Bill Wheaton of RTI, developed and used our computational simulation models of Allegheny County, Penn., and Pennsylvania to find two interesting things. First, as described in BMC Public Health, closing schools would not have enough of an effect to be worth the high cost of shutting down schools. Think of the resulting delays in educational progress, the makeup days that need to occur through normal vacation period, the extra cost of daycare for parents, and either teachers losing income or having to pay teachers while they are not teaching.
Secondly, as published in the Journal of Public Health Management and Practice, our modeling work showed that closing schools could even make an influenza epidemic worse, depending on how long the schools were closed. Huh? How is this possible? Well, imagine viruses as people on a trip who can stay in a car for only a week before having to find another car to drive. When people have been in a car for a week and cannot find another car to jump into then the trip ends. Similarly, if viruses cannot find new people to infect, an epidemic ends. Indeed, closing schools would prevent kids from mixing with and infecting each other...while the schools were closed, which would be analogous to cordoning off some cars so that people can't ride in them. Yet, once the schools re-open, as long as viruses were still around, the viruses would suddenly have a bunch of kids that it can newly infect, which could prolong the epidemic. This would be analogous to suddenly releasing the previously cordoned off empty cars so that people can keep finding new empty cars to continue the trip. Thus, for school closures to be effective, you may have to keep them closed for a very, very long time. Despite good intentions, closing schools in some situations could actually extend the epidemic and result in more people getting sick.
Thus, the evidence behind school closures as being an effective method of dealing with an influenza epidemic remains mixed as outlined in a review article by Mirat Shah and me in Expert Review of Anti-infective Therapy. Currently the evidence just is not strong enough to warrant mass school closure during a flu epidemic. Thus, during the 2009 pandemic, ultimately the Centers for Disease Control (CDC) recommended that schools remain open after initially suggesting that schools shut down immediately when students became ill.
This is just one example of infectious disease control being more complex than initially realized and how well-meaning approaches can have unintended bad consequences. So, what effect will canceling the Olympics have on the Zika epidemic? No one really knows, because the necessary studies haven't been done yet. Pengyi Shi, Pinar Keskinocak and Julie L. Swann from Georgia Tech University and I published a study in BMC Public Health that used a computational simulation model of the state of Georgia that explored the impact of mass gatherings (such as large concerts or sporting events) and holiday traveling on an influenza epidemic. We found that postponing or canceling large public gatherings may have some effect close to the peak of the epidemic but not earlier or later during the epidemic. Of course, flu transmission is quite different from Zika transmission, so more studies are needed.
What we do know is that canceling the Olympics will come at a high cost, in terms of money and affecting many, many lives, including athletes and everyone working for businesses and other efforts involved with the Olympics. (In a Baltimore Sun opinion piece, former Olympic medal-winning swimmer and associate at the UPMC Center for Health Security Tara Kirk Sell explains how athletes "would have their hearts broken and their Olympic dreams tossed aside.") Asking someone to cancel a party is easy when you are not the one organizing, hosting, paying for or even attending the party. Moreover, the Olympics are much more than a simple dinner party. Canceling the Olympics could have widespread detrimental economic effects on Brazil, which has already been struggling economically, as well as many other parts of the world. The Olympics are big business. Think of the potential ripple effects. Will such economic effects then impair Brazil's ability to control Zika, such as control its mosquito population? Does maintaining the Olympic spotlight on Brazil mean that the world is paying closer attention to Brazil and its efforts to control Zika? Could removing that spotlight remove this attention?
Moreover, calls for canceling the Olympics may distract from what really needs to be done, such as:
- Conducting studies (e.g., laboratory, clinical, epidemiological and computational modeling) to better understand the Zika virus and possible control measures
- Improving mosquito control.
- Developing a vaccine, treatments and better diagnostic tests for Zika.
- Communicating to the public about what precautions to take.
- Developing new ways to protect people.
- Tracking where the virus is going.
These are just some of things that should be done.
Also, what happens if canceling the Olympics has no effect or even makes things worse? Then, people will become suspicious of future urgent calls. It's the "boy who cried wolf" syndrome. Be careful about calling for drastic measures that will have major cost before the necessary studies have been done. Otherwise people may stop listening to you. And people not listening about future public health measures that are needed could have another chain of bad consequences.
All of this doesn't mean that the Olympics should not be canceled or postponed. It just means that much more information and studies are needed before a decision can be made. The same holds for other reasons being proposed for canceling the Olympics for other issues in Brazil such as water pollution. Calls for cancellation now would be like competing in an Olympic event without enough planning, practice or preparation.
