Abstract

abstract: “Porcine reproductive and respiratory syndrome virus (PRRSV) remains widely distributed across the U.S. swine industry. Between-farm movements of animals and vehicles, along with local transmission, are the primary spread routes. This study used spatial and spatiotemporal kernel density approaches to estimate PRRSV relative risk and a Bayesian spatiotemporal hierarchical model to assess the effects of environmental variables, movement data, and biosecurity features. The maximum spatial distance (local transmission risk) was calculated as 15.3–18.0 km between 2018 and 2020. Downstream farms (finisher and nursery) were located in areas of significant-high relative risk. Factors associated with outbreaks included farms with higher numbers of barn access points, higher numbers of outgoing pig movements, and more days with temperatures between 4°C and 10°C. These results can guide reinforced biosecurity and surveillance within specific distance thresholds of positive farms.”