#13,484
By now, just about every media outlet in the country has published something on the incident at JFK airport in New York today involving an Emirates Flight from Dubai - with a stopover in Saudi Arabia - arriving with (reportedly) dozens of ill passengers.
We should know something about the nature of these illnesses in the next few hours, and so I'll leave the speculation to the tabloid press and social media. We'll know soon enough.Most of the time, however, these incidents turn out to be something rather mundane - like seasonal flu or food poisoning. But of course, there's always the potential for something more serious.
What we can say is that international air travel can be a very competent vector for infectious diseases, and that attempts to screen passengers for MERS, Ebola, Lasa Fever, CCHF, or Avian flu (among others) are unlikely to be very effective.
Most viruses take days - sometimes a week or longer - to incubate. And with 7 million airline passengers each day, any attempts to identify and isolate infected passengers are probably doomed from the start.
According to early press reports (which are not always reliable) a number of passengers on today's flight were already symptomatic when they boarded. Ideally, if you are going to screen passengers, that's where you want to do it.
But as we saw during the start of the 2009 pandemic, some passengers were so desperate to make their flights they took antipyretic medications to beat the scanners (see Vietnam Discovers Passengers Beating Thermal Scanners).In 2012, in EID Journal: Airport Screening For Pandemic Flu In New Zealand, we looked at a study that found that the screening methods used at New Zealand’s airport were inadequate to slow the entry of the 2009 pandemic flu into their country, detecting less than 6% of those infected.
Despite the aggressive use of thermal imagers, passenger interviews, and other screening methods - Japan found it impossible to prevent entry of the H1N1 virus into their country during the early days of the 2009 pandemic.
In Japan: Quarantine At Ports Ineffective Against Pandemic Flu I wrote about a study that suggests between asymptomatic or mild infections, and a silent incubation period of several days, there wasn’t much chance of long-term success.
For every person identified, and quarantined, by port authorities - researchers estimate 14 others infected by the virus entered undetected.
Despite the inevitable calls for better airport screening, we have no technology that can realistically, or reliably detect asymptomatically infected individuals and prevent them from entering a country.Politically, and in terms of reassuring the public, the screening of passenger arriving at airports and other points of entry probably has some merit. And it may provide valuable surveillance information as well. But practically, as an effective way to keep an emerging virus out of a country, studies continue to show just how unlikely that outcome really is.
The only other option - closing borders completely - comes at a terrible cost, and for 99% of the world is simply unworkable (see New Zealand: Economic Evaluation Of Border Closure For A Generic Severe Pandemic Threat).While we may not be able to prevent the infectious diseases from crossing borders - or even oceans - we can be better prepared to deal with them when they do.
In 2015 the HHS Launched A National Ebola Training & Education Center to help prepare medical facilities to deal with emerging infectious disease threats, and in a TFAH Issue Brief: Preparing The United States For MERS-CoV & Other Emerging Infections, we looked at some of the steps that the United States needs to take to prepare for the arrival of MERS and other Emerging infections.
All very much worth doing because, in our increasingly mobile and interconnected global society, it really is just a matter of time.
