Study: Flu Viruses Travel on US Roads and Railways

<a href="http://www.istockphoto.com/photo/sick-woman-driver-64495947?st=b601613">kieferpx</a>/iStock

Facts matter: Sign up for the free Mother Jones Daily newsletter. Support our nonprofit reporting. Subscribe to our print magazine.


Viruses are hitching a ride with commuters on the nation’s roads and railways, adding to the chaotic movement that makes seasonal outbreaks difficult to track and contain.

In a study published Thursday in PLOS Pathogens, researchers at Emory University tracked genetic variations in two strains of influenza between 2003 and 2013. They concluded that states highly connected by ground transit tended to have similar genetic variations of the flu, and they matched their findings with illness case data that showed closely timed epidemic peaks in those states. The researchers believe ground transit connectivity may be a better indicator of where a disease is likely to spread than air travel connections or even geographic proximity, though they say both remain important factors.

The US Interstate Commuter Network shows the number of people traveling daily between states for work. Courtesy of Bozick, CC-BY

Modern transport networks complicate the movement of viruses: In the past, contagion moved person to person and village to village, resulting in “wave-like patterns” of genetic variation that correspond to geographic distance, the report says. But with 3.8 million people in the United States taking ground transportation across state borders each day and 1.6 million doing so by air, the spread of illness has become far more chaotic: Transcontinental flights help foster bicoastal outbreaks, while well-traveled commuter corridors between Kansas and Missouri may mean those states share illnesses as neighboring areas go unscathed.

Researchers found that “commuting communities,” divided into colored regions, tended to span state borders. Travelers carried influenza along with them. Courtesy of Bozick, CC-BY

The researchers hope their study, which they believe to be the first of its kind at the scale of the continental United States, will help epidemiologists better understand influenza’s seemingly unpredictable spread.

WE'RE TAKING A SHORT BREAK…

from the big banner at the top of our pages asking for the donations that make Mother Jones' nonprofit journalism possible. But we still have upwards of $300,000 to raise by June 30, whether we get there is going to come down to the wire, and we can't afford to come up short.

If you value the reporting you get from Mother Jones and you can right now, please join your fellow readers who pitch in from time to time to keep our democracy-advancing, justice-seeking journalism charging hard (and to help us avoid a real budget crunch as June 30 approaches and our fiscal year ends).

payment methods

WE'RE TAKING A SHORT BREAK…

from the big banner at the top of our pages asking for the donations that make Mother Jones' nonprofit journalism possible. But we still have upwards of $300,000 to raise by June 30, whether we get there is going to come down to the wire, and we can't afford to come up short.

If you value the reporting you get from Mother Jones and you can right now, please join your fellow readers who pitch in from time to time to keep our democracy-advancing, justice-seeking journalism charging hard (and to help us avoid a real budget crunch as June 30 approaches and our fiscal year ends).

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate