Scheduled airline traffic around the world, circa June 2009 – Credit Wikipedia
# 8067
Purely by chance, just weeks before the 2009 H1N1 virus broke out of Mexico and began to wing itself around the globe via international air traffic, I penned a blog called How The Next Pandemic Will Arrive. That blog was inspired by a video (below) made by ZHAW (Zürcher Hochschule für Angewandte Wissenschaften) showing 24 hours of air traffic around the world compressed into just over a minute.
Since then, we’ve looked at the role of air traffic in the spread of infectious disease a number of times, including a PLoS One study from MIT: Contagion Dynamics Of International Air Travel that simulated the early spread of a pandemic virus via air travel and ranked U.S. airports based on how much they contributed to the spread of the illness, and a number of studies suggesting that airport screening for infected travelers would likely be ineffective.
Branswell: Limitations Of Airport Disease Screening
Today, in the Journal Science, we get a new look at the simulated spread of a SARS or H1N1-like virus via international air travel from authors Dirk Brockmann and Dirk Helbing with the innocuous sounding title of:
The Hidden Geometry of Complex, Network-Driven Contagion Phenomena
Dirk Brockmann , Dirk Helbing
Science 13 December 2013:
Vol. 342 no. 6164 pp. 1337-1342
DOI: 10.1126/science.1245200
While the bulk of this study is behind a pay wall, we get a preview of its findings (and a fascinating video) from a press release via Berlin’s Humboldt-Universität.
(Click Image to view video)
The Hidden Geometry of Global Contagion
New mathematical theory for the global spread of epidemics
Scientists at Berlin’s Humboldt-Universität, ETH Zurich, Northwestern University and Robert Koch Institute develop a new mathematical theory for the global spread of epidemics. Insights cannot only facilitate finding an outbreak’s origin, but may significantly improve the forecast of global spreading pathways. The results of the study “The hidden geometry of complex, network-driven contagion phenomena” have recently been published in the journal Science.
When an unknown virus emerges at various locations in the world, scientists focus on answering the following questions: Where did the new disease originate? Where are new cases to be expected? When are they expected? And how many people will catch the disease? In order to contain the further spread – and potentially devastating consequences – rapid assessment is essential for the development of efficient mitigation strategies. Highly sophisticated computer simulations are an important tool for forecasting different scenarios: These simulations attempt to predict the likely epidemic time-course and spreading pattern. However, the computer simulations are very demanding in terms of computer time. They also require knowledge of disease-specific parameters that are typically not known for new, emergent infectious diseases.
Theoretical physicist Dirk Brockmann, Professor at Berlin’s Humboldt-Universität, and his fellow scientist Dirk Helbing, Professor at ETH Zurich, now propose a different approach for understanding global disease dynamics: “Our theory is based on the intuitive notion that in our strongly connected world, conventional geographic distances are no longer the key variable but must be replaced with effective distances,” they explain. “From the perspective of Frankfurt, Germany, other metropolitan areas such as London, New York or Tokyo are effectively not more distant than geographically close German cities such as Bremen, Leipzig or Kiel,” says Brockmann, who developed the ideas for this research at the Northwestern Institute on Complex Systems. In their work, the researchers show that effective distances can be computed from the traffic intensities in the worldwide air-transportation network: “If the flux of passengers from A to B is large, the effective distance is small and vice versa. The only thing we had to do was to find the right mathematical formula for this,” Helbing explains.
While I’ve said it before, it’s worth repeating:
The takeaway from all of this is that we ignore global healthcare and infectious disease outbreaks – even in the remotest areas of the world – at our own peril. Vast oceans and extended travel times no longer offer us protection, and there is no technological shield that we can erect that would keep an emerging pandemic virus out.
The place to try to stop the next pandemic is not at the airport gate, but in the places around the world where they are likely to emerge.
Which makes the funding and support of international public health initiatives, animal health initiatives, and disease surveillance ever so important, no matter where on this globe you happen to live.
