New York's John F Kennedy Airport is a teeming hub for international flight - and globe-trotting germs, a new study says.
The Massachusetts Institute of Technology paper published this week named JFK as the top of a list of "super-spreaders" in contagious diseases.
Next in the list came Los Angeles International, Honolulu, San Francisco, Newark Liberty, Chicago O'Hare and Washington Dulles, MIT said.
Top germ hub status doesn't actually mean the airports are disease-ridden themselves.
The study instead measured a wide variety of factors contributing to the airports' role in the spread of infectious disease. These include travel patterns, geographic location and waiting times.
The idea was to help understand and predict how viruses such as SARS and bird flu get around and prompt epidemics in an ever-more connected world.
"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," said Ruben Juanes, an energy studies professor.
"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 findings can be counter-intuitive.
The likes of Los Angeles and Chicago are well known for their heavy traffic, but Honolulu gets just 30 per cent as much air traffic as New York's JFK. However, the island airport is "nearly as influential in terms of contagion, because of where it fits in the air transportation network," the report said.
"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."