Estimating the effectiveness of control actions on African swine fever transmission in commercial swine populations in the United States

Analyzing the intrastate and interstate swine movement network in the United States

“…An in-depth understanding of national movement patterns is a key element for epidemic control in highly integrated swine production systems. In the same vein, examining interstate and intrastate pig shipment data is crucial to informing national disease response plans, and developing novel tactics against endemic and emerging diseases (Cardenas et al, 2022; Hammami et al, 2022b; Puspitarani et al, 2023; Sykes et al, 2023). The median distance of pig shipment was 74 km, similar to what has been shown in other regional studies with shipment distances between 10 and 50 km (Kinsley et al, 2019).…”

“…Long-distance disease spread events have been directly associated with the shipment of pigs (Buhnerkempe et al, 2014; Fèvre et al, 2006; Galvis et al, 2022b; Relun et al, 2016; Sykes et al, 2023). An in-depth understanding of national movement patterns is a key element for epidemic control in highly integrated swine production systems.…”

“…A European study that used real pig movement data and network modeling has demonstrated that between-farm movements may account for a staggering 99% of ASF transmission among commercial herds (Andraud et al, 2019). A more recent U.S. model simulation study showed that between-farm movement of swine was the predominant route of transmission of ASF, with an average contribution of 71.4% (Sykes et al, 2023). Given these results, an in-depth examination of real swine contact networks across multiple states would provide invaluable insights for developing response and recovery tactics.…”

“…The extraordinary complexity of between-premises animal movements, which change daily (Galvis et al, 2022a; Sykes et al, 2023), presents a formidable challenge for the swine industry and decision-makers who must implement effective disease control measures under time constraints. A European study that used real pig movement data and network modeling has demonstrated that between-farm movements may account for a staggering 99% of ASF transmission among commercial herds (Andraud et al, 2019).…”

“…The shipment of animals between premises has been widely recognized as the primary route involved in the transmission of infectious pathogens of swine such as African swine fever (ASF), porcine respiratory and reproductive syndrome virus (PRRSV), and foot-and-mouth disease (FMD) (Galvis et al, 2022a;Passafaro et al, 2020;Vinueza et al, 2022;Hammami et al, 2022a;Cardenas et al, , 2021Galvis et al, 2021;VanderWaal et al, 2020;Lee et al, 2017;White et al, 2017;Neumann et al, 2005;Pappaioanou and Gramer, 2010;Fèvre et al, 2006;. Disease intervention strategies involve reducing the number of between-premises animal movements; therefore, elucidating local and nationwide movement network patterns and identifying shipment hubs and road pathways used for pig shipment are expected to provide essential information about disease spread potential and efficient outbreak control (Puspitarani et al, 2023;Passafaro et al, 2020;Hammami et al, 2022a;Gorsich et al, 2019;Strano et al, 2018;Sykes et al, 2023. ) The U.S. swine industry is vertically integrated and comprised of approximately 64,871 premises, housing 72 million pigs in premises specializing in one or more production phases (e.g., farrow-to-wean, growing pig) (Passafaro et al, 2020;NASS et al, 2022;USDA and NASS, 2019;Reimer, 2006).…”