Infectious prions in the saliva and blood of deer with chronic wasting disease

A critical concern in the transmission of prion diseases, including chronic wasting disease (CWD) of cervids, is the potential presence of prions in body fluids. To address this issue directly, we exposed cohorts of CWD-na?ve deer to saliva, blood, or urine and feces from CWD-positive deer. We found infectious prions capable of transmitting CWD in saliva (by the oral route) and in blood (by transfusion). The results help to explain the facile transmission of CWD among cervids and prompt caution concerning contact with body fluids in prion infections.     

Prions in skeletal muscles of deer with chronic wasting disease

The emergence of chronic wasting disease (CWD) in deer and elk in an increasingly wide geographic area, as well as the interspecies transmission of bovine spongiform encephalopathy to humans in the form of variant Creutzfeldt Jakob disease, have raised concerns about the zoonotic potential of CWD. Because meat consumption is the most likely means of exposure, it is important to determine whether skeletal muscle of diseased cervids contains prion infectivity. Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.     

Economic analysis of land based farming of salmon

Abstract

Land-based farming of salmon is emerging for a number of reasons. The demand for salmon is increasing in many parts of the world. In recent years there has been limited growth in production due to binding government regulations and environmental challenges in sea-based salmon aquaculture. This is true both for Norway (sea lice, salmon escapes) and Chile (sea lice, disease problems), the two largest producers of salmon. Growing demand and limited expansion in production have made for a very profitable industry. At the same time, there have been technological developments when it comes to land-based farming (a technology used for smolt production and species such as sole and turbot), and cost of production has changed. Currently, land-based salmon farming is in operation or in development in several countries including the USA, Denmark, and Norway. In this paper, the economics of land-based salmon farming in a Norwegian context is presented, with an emphasis on the relative competitiveness of this vis-à-vis sea-based farming. If successful, land-based farming could potentially have an important impact on the dynamics of the salmon market.