If you want to play it safe, avoid airports in New York, Los Angeles and Honolulu - they're the ones most likely to play a part in spreading pandemics.
Health crises such as the 2003 SARS outbreak and the 2009 H1N1 flu pandemic have shown just how easily new viruses or bacteria can spread when air travel gives them a hand.
Now, MIT's examined how likely the 40 largest US airports are to play a part in this spread, with the hope of helping outbreaks be contained and dealt with in future.
Unlike existing models, the new one incorporates variations in travel patterns among individuals, the geographic locations of airports, the disparity in interactions among airports and waiting times.
"Our work is the first to look at the spatial spreading of contagion processes at early times, and to propose a predictor for which 'nodes' — in this case, airports — will lead to more aggressive spatial spreading," says MIT's Ruben Juanes.
"The findings could form the basis for an initial evaluation of vaccine allocation strategies in the event of an outbreak, and could inform national security agencies of the most vulnerable pathways for biological attacks in a densely connected world."
The results aren't always what you might expect. For example, while the Honolulu airport gets only 30 percent as much air traffic as New York's Kennedy International, it's nearly as influential in terms of contagion.
This is because of where it fits in the air transportation network: its location in the Pacific Ocean and its many connections to distant, large and well-connected hubs gives it a ranking of third in terms of contagion-spreading influence.
Kennedy Airport is ranked first by the model, followed by Los Angeles, Honolulu, San Francisco, Newark, Chicago O'Hare and Washington Dulles. Atlanta's Hartsfield-Jackson International Airport, which is first in number of flights, ranks eighth in contagion influence. Boston's Logan International Airport ranks 15th.
"We are currently capable of modeling with some detail real disease outbreaks, but we are less effective when it comes to identifying new countermeasures to minimize the impact of an emerging disease," says says Professor Yamir Moreno of the University of Zaragoza.
"The work done by the MIT team paves the way to find new containment strategies, as the newly developed measure of influential spreading allows for a better comprehension of the spatiotemporal patterns characterizing the initial stages of a disease outbreak."