According to a new MIT study, JFK and LAX are the two American airports of most concern to epidemiologists, but not because the quantity of passengers. From Rachel Ehrenberg at Science News:

“An infectious disease that really wants to go global would do well boarding planes at JFK or LAX, according to a new computer simulation that ranks U.S. airports by their potential to kick-start an epidemic. 

The simulation could help public health officials decide how and where to allocate resources such as vaccinations in the early days of an outbreak, says Ruben Juanes of MIT, who describes the analysis online July 19 in PLOS ONE.

Many simulations of how epidemics spread focus on the final outcome, such as how many people would ultimately be infected. This new work is mostly concerned with how the location of an initial outbreak affects the subsequent pandemic, says complex systems scientist Dirk Brockmann of Northwestern University in Evanston, Ill.

Surprisingly, the total number of passengers moving through an airport isn’t the deciding factor. By that measure, Atlanta’s airport — the busiest in the country — would be ideal for spreading germs. What’s key is how connected the airport is to other well-connected airports.

‘You are a good spreader if your neighbors are good spreaders,’ Juanes says. ‘That’s what’s really essential.'”