Chronic Wasting Disease Outbreak in Scandinavia

Abstract

Prion diseases are a family of rare and fatal progressive neurogenerative diseases, characterised by incubation periods up to several months or years, spongiform changes seen as neuronal loss, and no inflammatory response, commonly seen in more frequent viral and bacterial diseases, are visible in blood or cerebrospinal fluid The most known prion diseases are chronic wasting disease (CWD) in cervids, scrapie in sheep and goat, and bovine spongiform encephalopathy (BSE) in cattle. Creutzfeldt-Jakob disease (CJD) and the variant form (vCJD) and Kuru are examples of prion diseases occurring in humans. CWD is a fatal, neurodegenerative prion disease diagnosed in the family of Cervidae, including captive and free-ranging deer, elk, moose and reindeer in North America, South Korea, and recently in Scandinavia. CWD is one of the few TSEs considered highly infectious and are believed to be horizontally transmitted. In March 2016, CWD was for the first time diagnosed in Europe. A female reindeer from the wild reindeer area called “Nordfjella region zone 1” died during an attempt to chemically immobilise wild reindeer in Norway. In May and June, the same year, CWD was diagnosed in two Eurasian moose approx. 300 km. north of the first confirmed case, in Trøndelag county in central Norway and was for the first time discovered in red deer in Norway, October 2017 in the municipality of Gjemnes in mid-western Norway. Classical scrapie is a fatal, neurodegenerative prion disease affecting ovine and caprine species. The disease is known for almost 300 years, as the first case reported was in Great Britain in 1732 in sheep. Scrapie was for the first time diagnosed in Norway in 1958 in two rams imported from England, and Norwegian bred sheep in 1981.