Avian Influenza Networks

The World Health Organization has released dire predictions about the amount of deaths Avian Influenza can cause. While the numbers are extremely high (up to 1.5 billion deaths), there is one interesting factor in all of this - infectious disease networks.

In Linked, Albert-László Barabási explores networks and makes reference to the HIV/AIDS pandemic. The disease spreads through a number of ways, including sexual contact and sharing of needles. As such, one can model its spread through the use of social networks, as the only way one can get the disease is if one comes in contact with someone who has it.

Can the same apply to Avian Influenza? I believe so. Once a highly infectious strain of flu evolves, the first person to be infected will infect a number of people, who will in turn infect more, and so on. This is a network phenomenon, and as in the case of SARS, those who travel a great deal or come in regular contact with a large number of people will spread the disease quickly. Preventing those from getting the disease will slow the spread, though doing so will be difficult.

One interesting characteristic of networks is that they often appear with the "Power Law". Let's say you have a function, f(x) = y. Let x represent the number of people that caused y number of infections per person. For example, if x = 10 and y = 30, it means 10 people caused 30 infections each. Graphing such information will show you that f(x) is a curve exhibiting exponential decrease: one or two people caused a large number of infections, three or four a bit less, than a few dozen even less, and so on.

Yes, this is a mathematical model and yes, if Avian Influenza does as much damage as some predictions say, it will follow this model.