We’ve Been Looking at the Spread of Global Pandemics All Wrong

[xchrom]

http://www.theatlanticcities.com/commute/2013/02/weve-been-looking-spread-global-pandemics-all-wrong/4782/



Five hundred years ago, the spread of disease was largely constrained by the main mode of transportation of the time: people traveling on foot. An outbreak in one town would slowly ripple outward with a pattern similar to what occurs when a rock drops onto a surface of still water. The Black Death moved across 14th century Europe in much this way, like concentric waves unfurling across the continent.

Today, disease migrates across populations and geography with a curiously different pattern. In 2003, SARS first appeared in China, then spread to Hong Kong, then turned up from there in Europe, Canada and the United States. Plot the spread of the disease on a map of the world, and its movement looks downright random.

What has changed dramatically in the intervening centuries is not necessarily the diseases themselves, but human mobility networks. Dirk Brockmann, a theoretical physicist and professor of complex systems at Northwestern University, has long been interested in how evolving modes of long-distance transportation have changed many things: disease dynamics, the spread of information, the transport of species from one ecosystem to others where they don’t belong.

For about a decade, Brockmann and other researchers have been incorporating real datasets on the world air-transport network into models of disease dynamics. They can simulate an outbreak in one location and estimate its arrival in another. But early on, Brockmann noticed that models created by him and other colleagues often produced strikingly similar results, even with simulations built on different assumptions about infection rates, disease dynamics, seasonality, or the age structure of infected populations.

[phantom power]

1. money quote: "The real power of this insight comes from its diagnostic potential"

Sometimes, you just want to applaud

The real power of this insight comes from its diagnostic potential. Imagine a scenario where a new pandemic – its origins unknown – has already appeared in parts of China, Buenos Aires, Quebec, and Vancouver. This new representation of distance can help pinpoint the origin of the outbreak.

"It’s the only location from which the pattern looks concentric," Brockmann says. Any child, he adds, can tell you where the rock landed in the rippling water. "It’s at the center."

http://www.theatlanticcities.com/commute/2013/02/weve-been-looking-spread-global-pandemics-all-wrong/4782/

[tavalon]

2. That is the prettiest illustration of worldwide mayhem and death

Nice to get a chance to see it before we all die.

[kickysnana]

3. My college freshman niece was on a flight that stopped in Mexico City during SARS

before continuing on to the US. She got horribly sick as did the rest of the family but the CDC refused to TEST THEM FOR SARS because she only changed planes flew in a plane load of people who had been in Mexico City. She hadn't stayed in Mexico City. Duh!

She is the oldest in a family of 6 kids and Mom had to take so much time off with sick kids and herself that she lost her teaching position that was not yet tenured. Principal was a genuine ass*****. Her hubby had just retired from the Marines and they had been all over the world.

She now is in a great school with a great principal so it ended well and the two years she was subbing my parents died a year apart so she was able to say no to job assignments and not get penalized.

[SheilaT]

4. Another aspect of potentially

devasting pandemics which I don't think has been considered, is which would be worse: one with a very short incubation period or one with a very long one? From what I think I know about these things, the latter would be far worse and make effective quarantines much harder.

One reason AIDS got such a foothold was that it did have a long incubation period before the symptoms showed up. Plus, of course, a real misunderstanding for a long time of exactly what it was and how it spread. If something similar came up, that in some way spread just a little differently from what's expected, it could be quite devastating.