Contact Networks and the Spread of MRSA in Stockholm Hospitals

We have been studying the spread of meticillin (multi) resistant Staphylococcus Aureus (MRSA). In the course of these studies, we investigated information about all patient visits within Stockholm County during the outbreak period, with registry over all diagnosed MRSA cases. As part of this project, we developed methods for analyzing the contact network of persons who had visited the same care facility, as well as methods for analyzing the affects of network structure on the transmission of MRSA. We also studied matrixes of disease transition in hospital populations (infected patients vs. Merely contagious patients). In the stationary case: (a) we have estimator matrixes of probabilities and other statistical properties of the contact networks. In the time evolution case: (b) we divided the outbreak into smaller, periodic intervals and looked at how MRSA spread over time. The MCqMC (Markov chain quasi Monte Carlo) method and artificial networks (whose main parameter is the number of contacts during a specific time interval) help us to understand real and simulated-paths of disease transition. Probability matrices (b) were used to find the mechanism of change states (vectors of all population, 0-susceptible or 1-infected).