Epidemic dynamics on the commute network in Tokyo metropolitan area

Epidemic dynamics of an infectious disease spreading over the commute network in Tokyo metropolitan area is analyzed using a simple mathematical model. The model is formulated based on the meta-population connected by railway lines where populations (trainstations) are interconnected by commuter flows (commuter railway network). Here, the actual data from the Urban Transportation Census (Japanese Ministry of Land, Infrastructure, Transport and Tourism) is used to simulate the movements of commuters. The effect of infectiousness of pathogen and the structure of commute network are investigated and the following results are obtained. i) The probability of global epidemic is mainly determined by the joint distribution of home and work population sizes of commuters, but is insensitive to the geographical or topological structure of the network. ii) The first passage time of epidemic at each populations follows a power law distribution against it's population size.