Networks Play a Role in PRRS Spread

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Networks Play a Role in PRRS Spread

04 July 2012

CANADA - A researcher with the University of Guelph reports the networks that connect pigs, especially ownership and trucking networks, are emerging as key factors in the spread of Porcine Reproductive and Respiratory Syndrome, Bruce Cochrane writes.

With funding provided by the Canadian Swine Health Board, researchers with the University of Guelph are using advanced techniques, including developing computer models, to identify key factors that play a role in the spread of Porcine Reproductive and Respiratory Syndrome.

Dr Zvonimir Poljiak, a swine epidemiologist in the Department of Population Medicine at the Ontario Veterinary College at the University of Guelph, says the goal is to determine the contribution of such factors as spatial location, trucking, animal sources, feed sources and semen sources to the transmission of the PRRS virus at a herd level.

Dr Zvonimir Poljiak-University of Guelph

I think the key finding is, what are the most important networks that are contributing to the spread of disease.

What I mean by network is, herds today are somehow grouped into ownerships.

Maybe some of them do not cluster spatially together so we have to take into account this clustering of ownerships in space when we are evaluating some of the ways that virus is spreading spatially.

The other important factor beside the ownership is really the trucking, The trucking networks could be identified as important for disease spread, depending on whether we are talking about all herds or only sow herds.

The other factor that is also very important is the gilt sources. We always knew that these are important networks for spread of disease anyway but it was nice to actually see that something that is biologically plausible is actually coming from these models as something that really contributing to the spread of this particular genotype.

Dr Poljiak says by identifying the networks that seem to be most important for disease spread, we can track the most important variables and, in the long run, that will help us design better intervention strategies and better surveillance strategies.