On reproductive and respiratory syndrome virus dissemination across pig production systems in the United States

Manuel Jara; David A. Rasmussen; Cesar A. Corzo; Gustavo Machado

The reconstructed spatiotemporal diffusion of PRRSv was characterized by continuous expansion in the 227 geographic space, accompanied by diversification events. The comparison between each system and all 228 samples together showed two noticeable patterns. The first one was characterized by a radial expansion 229 over time, found when all samples were analyzed together and within samples of system A. In contrast, 230 systems B and C evidenced a directional trend, since for both systems the spread started in the southwest 231 . CC-BY-NC-ND 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.09.034181 doi: bioRxiv preprint region. In the case of system B, PRRSv spread to the northeast, while for system C, the spread was 232 mainly to the north, though spread did occur in all directions (see Supplementary Figs. S1-3). 233