Abstract

Several propagation routes contribute to animal disease dissemination, with contaminated vehicles traveling between farms being a significant factor in indirect disease transmission. This study utilized near-real-time vehicle movement data and vehicle cleaning efficacy to reconstruct the dissemination of the African swine fever virus (ASFV) between farms. The researchers collected one year of Global Positioning System data from 823 vehicles transporting feed, pigs, and personnel to 6363 swine production farms across two U.S. regions. Without cleaning, vehicles were found to connect up to 2157 farms in one region and 437 farms in the other. Specifically, in region one, feed-transporting vehicles connected 2151 farms, vehicles moving pigs to farms connected 2089 farms, those moving pigs to market connected 1507 farms, undefined vehicles connected 1760 farms, and personnel transport connected three farms. The simulation results indicated that contact networks were reduced most significantly for crew transport vehicles, showing a 66% reduction, followed by vehicles transporting pigs to market and farms, with reductions of 43% and 26% respectively, when 100% cleaning efficacy was achieved. The study’s findings highlight that even with 100% effective vehicle cleaning and disinfection, vehicles still maintain connections to numerous farms. This underscores the critical need for a better understanding of the transmission risks posed by vehicles to the swine industry and regulatory agencies.