Policy implications of an expanded chronic wasting disease universe

International policy for the management of wildlife disease(s) plays an important role for concerted action, and changes to policy should be evidence-based and updated as new evidence accumulates. Management of chronic wasting disease (CWD), the prion disease affecting cervids, is based on its highly contagious nature relative to most other prion diseases. These management actions are particularly invasive, with considerable biological and economic consequences. A novel type of CWD has been discovered in moose Alces alces and red deer Cervus elaphus, with prions restricted to the central nervous system (CNS). Prions in tissue outside the CNS are an indication of the contagiousness of a prion disease. As such, for this novel type of CWD, there is a lower likelihood of horizontal transmission under natural conditions. Furthermore, infected individuals were older (mean 15 years), and cases appeared with limited clustering in space and time; hence, with no indication of an epidemic outbreak. Policy implications. The annual harvest of approximately 4 million cervids in Europe each year generates considerable cultural and economic value. 'Stamping out' policies would be inefficient and inappropriate to control diseases with no horizontal transmission among live animals, and banning the export of meat from a region after detection of a positively tested animal would make little sense in the case of sporadic disease. The novel type of chronic wasting disease (CWD) with epidemiological characteristics clearly different from 'classical' and contagious CWD calls for differentiated management strategies to avoid unnecessarily invasive actions.

Automated summary

International policies for wildlife disease management are key for coordinated action, based on accumulating evidence. Chronic wasting disease (CWD), affecting cervids, is managed due to its high contagious nature, with a novel type discovered in moose and red deer that calls for differentiated management. Successful strategies should consider the epidemiological characteristics of the disease to avoid unnecessary invasive actions.