Papers

Estimation of distance related probability of contact between farms through anumal transports and implications for disease spread modelling.
T. Lindström, S. A. Sisson, M. Nöremark, A. Jonsson and U. Wennergren (2009). Preventive Veterinary Medicine, 91, 85-94. doi:10.1016/j.prevetmed.2009.05.022
[Preprint]

Abstract: The dynamics of disease spread between farms can be largely affected by how the probability of contact depends on distance. We present a method for analyzing distant dependent contacts and apply it to animal transport data. Distance related deviations from the assumption of mass action mixing (all contacts being equally probable) in contacts through live animal movements between farms are estimated with two models of different complexities using a Bayesian Markov Chain Monte Carlo (MCMC) approach. The model probabilities are compared and between model differences in predicted contact structure are tested using a number of network measurements. The more complex model was found to better describe the observed transport data and in particular long distance contacts. The models also differ in their predictions on contact pattern and hence also expected dynamic of disease spread. It is concluded that the more complex model is required to describe the contact pattern and should preferably be used for spatial studies of disease transmission through live animal transports.

Keywords: Markov Chain Monte Carlo; Mixture Models; Model Selection; Animal Transports; Disease Transmission; Network Analysis.