Prions and animal transmissible spongiform encephalopathies

Polona Juntes,Jelka Zabavnik-Piano,Ambrozic Ivan

doi:10.2298/vetgl170302004j

Abstract

Background. Transmissible spongiform encephalopathies (TSEs) or prion diseases are a unique group of neurodegenerative diseases of animals and humans, which always have a fatal outcome and are transmissible among animals of the same or different species. Scope and Approach. The aim of this work is to review some recent data about animal TSEs, with the emphasis on their causative agents and zoonotic potential, and to discuss why the surveillance and control measures over animal TSEs should remain in force. Key Findings and Conclusions. We still have incomplete knowledge of prions and prion diseases. Scrapie has been present for a very long time and controlled with varied success. Bovine spongiform encephalopathy (BSE) emerged unnoticed, and spread within a few years to epidemic proportions, entailing enormous economic consequences and public concerns. Currently, the classical BSE epidemic is under control, but atypical cases do, and probably will, persist in bovine populations. The Chronic Wasting Disease (CWD) of the cervids has been spreading in North America and has recently been detected in Europe. Preventive measures for the control of classical BSE remain in force, including the feed ban and removal of specified risk materials. However, active BSE surveillance has considerably decreased. In the absence of such preventive and control measures, atypical BSE cases in healthy slaughtered bovines might persist in the human food chain, and BSE prions might resurface. Moreover, other prion strains might emerge and spread undetected if the appropriate preventive and surveillance measures were to cease, leaving behind inestimable consequences.

Highlights

Transmissible spongiform encephalopathies (TSEs) or prion diseases are a unique group of neurodegenerative diseases of animals and humans with an invariably fatal outcome
The aim of this work is to review our current knowledge of animal TSEs, focusing on causative agents and zoonotic potential of scrapie, bovine spongiform encephalopathy (BSE) and chronic wasting disease (CWD), and to substantiate that, classical BSE is successfully controlled, the current surveillance and control measures for animal TSEs are still necessary (EFSA, 2016)
A recent study by Masujin et al (2016) further showed that the H-type BSE can transform into a novel type of BSE (BSE-SW) through serial subpassages in bovinised transgenic mice (TgBoPrP). This different type has a shorter incubation period and different phenotype than the original H-type, and a similar biochemical profile as classical BSE. Results of this Japanese study suggest that intraspecies transmission of H-type BSE in cattle allows the emergence of a novel BSE strain

Summary

Introduction

Transmissible spongiform encephalopathies (TSEs) or prion diseases are a unique group of neurodegenerative diseases of animals and humans with an invariably fatal outcome. The aim of this work is to review our current knowledge of animal TSEs, focusing on causative agents and zoonotic potential of scrapie, BSE and CWD, and to substantiate that, classical BSE is successfully controlled, the current surveillance and control measures for animal TSEs are still necessary (EFSA, 2016). Transmissible spongiform encephalopathies (TSEs) or prion diseases are a unique group of neurodegenerative diseases of animals and humans, which always have a fatal outcome and are transmissible among animals of the same or different species. The aim of this work is to review some recent data about animal TSEs, with the emphasis on their causative agents and zoonotic potential, and to discuss why the surveillance and control measures over animal TSEs should remain in force

Objectives

Results

Conclusion