New perspectives for evaluating relative risks of African swine fever virus contamination in global feed ingredient supply chains

Abstract

There are no published reports indicating that the African swine fever virus (ASFV) has been detected in feed ingredients or complete feed. This is primarily because there are only a few laboratories in the world that have the biosecurity and analytical capabilities of detecting ASFV in feed. Several in vitro studies have been conducted to evaluate ASFV concentration, viability and inactivation when ASFV was added to various feed ingredients and complete feed. These inoculation studies have shown that some feed matrices support virus survival longer than others and the reasons for this are unknown. Current analytical methodologies have significant limitations in sensitivity, repeatability, ability to detect viable virus particles and association with infectivity. As a result, interpretation of findings using various measures may lead to misleading conclusions. Because of analytical and technical challenges, as well as the lack of ASFV contamination data in feed supply chains, quantitative risk assessments have not been conducted. A few qualitative risk assessments have been conducted, but they have not considered differences in potential scenarios for ASFV contamination between various types of feed ingredient supply chains. Therefore, the purpose of this review is to provide a more holistic understanding of the relative potential risks of ASFV contamination in various global feed ingredient supply chains and provide recommendations for addressing the challenges identified.

Rethinking the uncertainty of African swine fever virus contamination in feed ingredients and risk of introduction into the United States

“…In general, bulk commodity ingredients such as corn and soybean meal are transported in containers or large holds in various sizes of ocean-going ships, which may have higher risk of ASFV contamination and less traceability than specialized and often branded feed additives and ingredients (e.g. synthetic amino acids and vitamins) that are packaged in bags or totes and placed on pallets before being loaded into containers for ocean transport (Shurson, Pawlowski, et al, 2021). We chose to model three types of bulk feed ingredients (i.e.…”

“…We chose to model three types of bulk feed ingredients (i.e. corn grain, extruded soybean meal, and solvent extracted soybean meal) that are commonly used in swine diets and imported in significant quantities annually into the United States (Shurson, Pawlowski, et al, 2021). For modelling purposes, we assumed that each of these bulk ingredients would be imported in 25,000 tonnes vessels, which is commonly done.…”

“…Although there is scientific evidence indicating that ASFV can survive in certain feed ingredients and contaminated food products for extended periods of time, there are no regulatory or surveillance programmes established for determining the presence and viral load of ASFV in complete feed and feed ingredients (Shurson, Pawlowski, et al, 2021). The most important reasons for the lack of regulatory surveillance are the lack of validated diagnostic tests and sampling protocols to quantify viable ASFV particles in feed ingredients, the limited number of laboratories to conduct ASFV assays worldwide, and the uncertainty around the ASFV infectious dose through feed (Shurson, Pawlowski, et al, 2021). As a result, initial qualitative risk assessments have been conducted to assess the risk of ASFV entry into the United States through contaminated imported feed ingredients (USDA-APHIS, 2019), and the inherent risk of different swine bacterial and viral pathogens in feed ingredients (Jones et al, 2020).…”

Modelling and assessing additional transmission routes for porcine reproductive and respiratory syndrome virus: vehicle movements and feed ingredients

“…The dramatic change in the global epidemiological situation of African swine fever (ASF) spread has resulted in concerns about its spread via feed and transportation vehicles moving between-farms and countries (Lee et al, 2017; Elijah et al, 2021; Mighell and Ward, 2021; Niederwerder, 2021; Shurson et al, 2021). However, there is limited information about the contribution of both vehicle movements and the delivery of specific feed ingredients (i.e.…”

Feed: A new pathway for the domestic and transboundary spread of viral pathogens of veterinary significance

“…The Special Issue opens with a review of the literature focused on the question of whether we can effectively manage the risk of parasites, prions and pathogens in the global food industry (Shurson et al, 2021a). This is followed by a second review focusing on new perspectives for evaluating the risk of African swine fever virus (ASFV) in global feed ingredient supply chains (Shurson et al, 2021b). Following the reviews, two case studies describe PEDV infection through contaminated feed and feed transport, including an overview of interventions applied to manage this risk.…”