Using heterogeneity in the population structure of U.S. swine farms to compare transmission models for porcine epidemic diarrhoea

Eamon B. O’Dea; Harry Snelson; Shweta Bansal

Our analyses were likely limited in power by inaccuracies in our variables measuring population structure. For example, the transport flows used excluded transport to harvest plants, and such movements have been observed 10 to result in the contamination of trailers. Another concern is the coarseness and age of the flow estimates. In support of them being sufficiently informative, previous phylogeographic analysis 43 The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/017178 doi: bioRxiv preprint farms tend to specialise on specific production stages. But if larger farms did not experience more PED outbreaks but only reported them with higher probability, that could provide a false signal that flows are associated with risk. A phylogeographic analysis or analysis of suitably structured epidemiological data could establish an association between flows and spread of PEDV that is not subject to such confounding.