Epidemics and Travel Bans

Here’s something that doesn’t happen often: I disagree with my friend, podcast co-host, and former mentor Vincent Racaniello. He’s generally right about most things. But I have to part ways with his take on public health-related travel bans, which he explained in a recent post on his blog:

Why is it important to stop travel out of the [Ebola virus] affected countries? While I’m confident that the US can detect and properly contain imported Ebola virus infections, not all countries will be able to do so. There are dozens of other countries that are unprepared to deal with an infected case, from diagnosis to isolation to treatment. I can easily imagine infection quickly getting out of control in such countries: millions are at risk. While the economics of stopping air travel out of Liberia, Sierra Leone, and Guinea will be severe, they cannot approach the devastation of having outbreaks burning simultaneously in multiple countries.

Vincent isn’t alone in wanting to ban flights from these three countries, as the world continues to watch their Ebola epidemics spiral out of control. It seems like a rational response, until you think about how it would really play out.

We don't have to guess. In 2003, the world saw a terrifying regional epidemic that threatened to develop into a global disaster if not checked: SARS. The response covered all of the same arguments now being made about Ebola, though the respiratory virus that causes SARS is more contagious than Ebola virus. After much hand-wringing, many countries implemented temporary travel policies aimed at curbing the spread of SARS, but to my knowledge no country actually banned flights from the affected areas. Even the most restrictive countries at the height of that epidemic only stipulated that people arriving with a fever had to be hospitalized, tested, and quarantined. They didn’t ban travel. You can read a very informative and detailed report about the effects of those restrictions in the CDC’s report on the outbreak.

The US was even less restrictive. The CDC screened passengers at airports and recommended delaying non-essential travel to a few specific destinations. That was a recommendation, not a regulation, and it’s not clear the CDC even has the legal ability to mandate such a restriction. The WHO “travel restrictions” at the time were also recommendations, as the WHO does not have the authority to dictate national policies. In short, a travel ban for Ebola virus would be a really extreme move.

Besides being excessive, the historical evidence tells us such a ban would likely be counterproductive. Even without outright travel bans, the limited quarantines some countries put in place for SARS caused serious problems and probably didn’t help much. As the CDC report explains:

Officials in Taiwan now believe that its aggressive use of quarantine contributed
to public panic and thus proved counterproductive. In virtually all jurisdictions there
were some incidents of violation of quarantine. In Toronto, the two groups most likely to violate quarantine were teenagers and health care workers.

Ban flights to the US from Sierra Leone, Guinea, and Liberia, and folks will simply find an alternate route to another country before starting the US-bound leg of their journey. Worse, by encouraging people to evade the direct routes, we’d completely lose the ability to track arrivals from the affected countries, and also discourage them from telling their doctors about their travels if they got sick after arriving here. Anyone flying in from anywhere could’ve originated in a country with Ebola. The tendency of healthcare workers to violate quarantines during the SARS outbreak is particularly troubling, as that’s exactly the group most likely to be exposed to Ebola virus in the current epidemic.

Finally, we need to remember that a ban on transportation out of a country is a de facto ban on transportation into it. No airline, shipping company, or cargo carrier is going to send crews into a place they can’t get them back out of. It’s already a logistical nightmare to get equipment and people into the Ebola-affected areas to help. With a travel ban, it would be virtually impossible. The world would essentially be saying “you’re on your own.” The ensuing panic in those countries would send people running for their porous borders immediately. A travel ban would be tantamount to telling everyone to bug out and flee.

I don’t think the US should halt incoming travelers from any country because of Ebolavirus. It would be a radical, unprecedented, and probably illegal measure which would only worsen the course of the epidemic. That’s not to say we shouldn’t take precautions. I fully favor screening incoming international passengers at airports and sending anyone with a fever for a medical evaluation. American hospitals and clinics should also be on their toes, asking everyone with an unexplained illness about any recent travel. Those are sensible measures that worked well against SARS, and they’ll work just as well against a less-contagious virus such as Ebola.