How the Spread of Ebola Mirrors a Growing Network
http://www.bbc.com/news/world-africa-28755033
The recent Ebola crisis in West Africa was the largest Ebola outbreak in known history, and became a worldwide issue, raising fears of possible contagion. Beginning in a small village in south-eastern Guinea, the disease radiated outwards, affecting districts across Guinea, Liberia, and Sierra Leone. Some patients who traveled through West Africa brought the disease to other parts of Africa, the United States, and Europe, but in most cases the patients were successfully treated and no major Ebola outbreaks occurred. Since then, all three countries in West Africa have been declared Ebola-free.
The Ebola outbreak in West Africa, along with many diseases, is an example of a network developing overtime, and as such, displays many of the network effects that we have been discussing in class. For example, if one observes the spread of the disease over time in the maps the article provides, one can see how the disease began concentrated around its origin point in Gueckedou, and overtime began propagating outwards, first infecting districts that were adjacent to infected districts. This effect is logical, since close proximity to an infected district increases the likelihood that the disease can spread over borders. In fact, in one observes the districts, one can see that the triadic closure holds true in many cases. If a district is adjacent to two infected districts, within a couple months the district is usually also infected. This makes sense as well, seeing as the more districts which could potentially transmit the disease would lead to an increased likelihood of infection. However, the effect of triadic closure did not always hold. For example, some districts remained uninfected despite being completely surrounded by infected districts. A possible explanation is the district made strong efforts to prevent transmission across borders, perhaps restricting travel or having health inspections. This also likely explains partly why the Ebola virus did not strongly affect countries outside of West Africa, the disease was contained through strict border controls.
In conclusion, the propagation of disease can be described using some network intuition. By understanding the nature of networks, people can understand how diseases spread throughout communities and better learn how to prevent contagion.