A dynamic spatio-temporal model to investigate the effect of movements of animals on the spreading of Bluetongue BTV-8 in Belgium

Abstract

When Bluetongue Virus Serotype 8 (BTV-8) was first detected in Northern Europe in 2006, several guidelines were immediately put into place with the goal to protect farms and stop the spreading of the disease. This however did not prevent further rapid spread of BTV-8 across Northern Europe, which has resulted to substantial economic losses, particularly in the sheep and cattle industry (Wilson and Mellor, 2009).

A better understanding of the BTV-8 transmission is needed to be able to define appropriate control guidelines. Using information on the 2006 Bluetongue outbreak in cattle farms in Belgium, a spatio-temporal transmission model was formulated, similar to the model proposed by Hooten et al (2010) for Influenza in North America. The model quantifies the local transmission of the disease between farms within a municipality, the short-distance transmission between farms across neighboring municipalities and the long-distance transmission as a result of the movement of animals. Different municipal-level covariates (i.e. farm density, land composition variables, temperature and precipitation) were assessed as possibly influencing each component of the transmission process.

The model allows to predict the dynamic spreading of the disease for different scenarios. This is especially useful in investigating the impact of movement (or lack of movement) of animals between farms in the transmission of bluetongue.