Emerging Zoonotic Diseases: Should We Rethink the Animal–Human Interface?

Antimicrobial Usage and -Resistance in Livestock: Where Should We Focus?

Recombinant pestivirus envelope glycoprotein E^rnshas been shown to interfere with dsRNA-induced interferon (IFN-α/β) synthesis. This study demonstrated that authentic, enzymically active E^rnsproduced in mammalian cells prevented a dsRNA-induced IFN response when present in the supernatant of bovine cells. Strikingly, IFN synthesis of cells expressing E^rnswas eliminated after extracellular addition, but not transfection, of dsRNA. Importantly, the same applied to cells infected with bovine viral diarrhea virus (BVDV) expressing E^rnsbut lacking the N-terminal protease N^pro. Free E^rnsconcentrations circulating in the blood of animals persistently infected with BVDV were determined to be approximately 50 ng ml⁻¹, i.e. at a similar order of magnitude as that displaying an effect on dsRNA-induced IFN expressionin vitro. Whilst N^problocks interferon regulatory factor-3-dependent IFN induction in infected cells, E^rnsmay prevent constant IFN induction in uninfected cells by dsRNA that could originate from pestivirus-infected cells. This probably contributes to the survival of persistently BVDV-infected animals and maintains viral persistence in the host population.

Biosecurity is crucial for safeguarding livestock from infectious diseases. Despite the plethora of biosecurity recommendations, published scientific evidence on the effectiveness of individual biosecurity measures is limited. The objective of this study was to assess the perception of Swiss experts about the effectiveness and importance of individual on-farm biosecurity measures for cattle and swine farms (31 and 30 measures, respectively). Using a modified Delphi method, 16 Swiss livestock disease specialists (8 for each species) were interviewed. The experts were asked to rank biosecurity measures that were written on cards, by allocating a score from 0 (lowest) to 5 (highest). Experts ranked biosecurity measures based on their importance related to Swiss legislation, feasibility, as well as the effort required for implementation and the benefit of each biosecurity measure. The experts also ranked biosecurity measures based on their effectiveness in preventing an infectious agent from entering and spreading on a farm, solely based on transmission characteristics of specific pathogens. The pathogens considered by cattle experts were those causing Bluetongue (BT), Bovine Viral Diarrhea (BVD), Foot and Mouth Disease (FMD) and Infectious Bovine Rhinotracheitis (IBR). Swine experts expressed their opinion on the pathogens causing African Swine Fever (ASF), Enzootic Pneumonia (EP), Porcine Reproductive and Respiratory Syndrome (PRRS), as well as FMD. For cattle farms, biosecurity measures that improve disease awareness of farmers were ranked as both most important and most effective. For swine farms, the most important and effective measures identified were those related to animal movements. Among all single measures evaluated, education of farmers was perceived by the experts to be the most important and effective for protecting both Swiss cattle and swine farms from disease. The findings of this study provide an important basis for recommendation to farmers and policy makers.