Worldwide occurrence of animal TSEs.

<p>(A&B) Show the worldwide prevalence of BSE cases, from 1987 to 2017. Total number of cases shown in C-F is from active and passive surveillance according to the World Organization for animal health, Paris (OIE). (C&D) Show the prevalence of scrapie cases worldwide over the last years, whereas (E) graphs show the percentage of the CWD positive cases of total animals examined for surveillance in the states of Alberta and Saskatchewan, according to the Department of agriculture and forestry, Alberta, and the Canadian Wildlife Health Cooperative. (F) Distribution of CWD in over 20 states of the USA and two Canadian provinces, as of October 2017, according to Geological Survey by the Department of the Interior/USGS, US Geological Survey. CWD, Chronic Wasting Disease.</p