In my experience, one of the quickest ways to catch the current flu/cold/enter name of any other contagious illness here, is to fly. I was 15 when I traveled by plane the first time. I’d joined chorus in high school so I could go on the chorus and band trip with my friends. I couldn’t sing to save my life, but that didn’t figure into my equation. Soon after disembarking from the plane, I discovered that I’d lost my voice somewhere in the air space between Massachusetts and Florida. My choral companions were quite pleased with this fortuitous event since it meant their chances in the competition were markedly improved without my off key warble in the mix.

There are many reasons cited as the explanation of why airplanes and airports encourage contagion. The most common one I’ve heard is recirculated air, but the sheer quantity of people who pass time, long or brief, in a major airport on any given day is astounding. On average 190,000 people pass through Chicago’s O’Hare airport, and 165,000 through LAX in a single day (I can’t entirely vouch for the quality of these statistics, but they sound believable). What are the chances that a few of those people have some unpleasant bacteria or virus hitching a ride?

Researchers in MIT’s Civil and Environmental Engineering department created the above simulation showing how a contagion spreads through mass air travel (US based airports only) in the early days of an epidemic. Their research highlights the airports that serve as nexuses. The reason why these airports serve as a feeder pool is quickly evident – they are simply the busiest travel hubs. If you fly with any regularity, that airport where you would most likely catch a connecting flight, it’s on the list. JFK, LAX and Honolulu came out on top.

This isn’t the first time a predictive model has been created to map the spread of disease, but this one took some different approaches:

Unlike existing models, the new MIT model incorporates variations in travel patterns among individuals, the geographic locations of airports, the disparity in interactions among airports, and waiting times at individual airports to create a tool that could be used to predict where and how fast a disease might spread. 

Ruben [Juanes, the ARCO Associate Professor in Energy Studies] studies of the flow of fluids through fracture networks in subsurface rock and the research of CEE’s Marta González, who uses cellphone data to model human mobility patterns and trace contagion processes in social networks[. This research] laid the basis for determining individual travel patterns among airports… Existing models typically assume a random, homogenous diffusion of travelers from one airport to the next.

 [P]eople don’t travel randomly; they tend to create patterns that can be replicated. Using González’s work on human mobility patterns, Juanes and his research group… applied Monte Carlo simulations to determine the likelihood of any single traveler flying from one airport to another.

Your first thought may be “I need to change my layover” or “I guess I should buy one of those face masks that Michael Jackson used to wear” but I’d suggest some simple hand washing, resisting the urge to bite your nails (yeah – one of my bad habits), eating that french fry you dropped on the TGI Friday’s table – you get the idea. On the bright side, this research may help determine how to improve the distribution of vaccines to dampen the spread of illness. So, if you do get sick while you’re traveling, think if it as taking one for the team.

- via MIT News