Chronic wasting disease (CWD) is a deadly prion disease in cervids, first described in the United States in the late 1960s. Since then, it has spread to many other states and to Canada.
Other prion diseases are BSE in cattle, scrapie in sheep, and Creutzfeldt Jakob disease (CJD) in humans. Among prion diseases in animals, only BSE has been shown to be transmitted to humans and has resulted in deaths from variant CJD. Although CWD is only considered an animal disease, recent reports of experimental oral transmission to monkeys (macaques) give cause for concern.
In Europe, CWD was detected in 2016, in wild reindeer in Norway and also in moose and one red deer.
Studies have shown that there are differences between CWD strains found in cervids in Fennoscandia and in North America, and further that there are also differences between the strains found in wild reindeer, moose and red deer in Norway. This means that risk assessments and disease management can not only be based on knowledge from North America, and that there is an urgent need for research on CWD prions found in Europe.
The project will integrate research on disease development, infection spread and population dynamics, and will, through modeling, contribute to the assessment of surveillance strategies.
Furthermore, the project will help to shed light on genetic factors with possible significance for disease development, which may be relevant for use in disease control through breeding programs.
The risk of transmission of European CWD prion strains to sheep, cattle, pigs and humans will be assessed using an ultra-sensitive method (PMCA) for the detection of prions, and experiments with live rodents (transgenic mice expressing prion protein from another species). Understanding which CWD strains are most likely to cause disease in different species (crossing species barriers), and which species are most exposed, will make it possible to improve monitoring and control measures.
Chronic wasting disease (CWD) is an emergent prion disease first identified the late 1960s, which has since spread rapidly among cervids in North America with devastating consequences for populations in some areas. Among prion diseases, BSE can transmit to humans and has resulted in >220 deaths from variant CJD. Although there is no epidemiological evidence to date suggesting spread of CWD to humans, recent reports of experimental oral transmission to non-human primates give cause for concern. In Europe the first cases of CWD were identified in 2016 in wild reindeer (20) in Norway. Additional cases were found in moose in Norway (7), Finland (2) and Sweden (4), and 1 red deer in Norway. Biochemical properties of prions from Norwegian CWD cases and their transmission in rodent models have shown that the European and North America CWD strains are different. This means that risk assessments and control strategies cannot not be solely based on evidence from CWD in North America, and that further research specific to the European context is urgently required. This project will integrate research on the epidemiology and population dynamics of the disease in affected countries, and through mathematical and statistical models, will evaluate surveillance strategies. The outcomes will have an impact on the modelling of CWD spread, and may also identify PRNP alleles associated with disease resistance that could be used in selective breeding programmes for disease control. The risks of transmission of European CWD isolates to sheep, cattle, pigs and humans will be assessed using the in vitro method PMCA and in vivo models (transgenic mice expressing PrP from the target species). Understanding which CWD strains are most likely to cross species barriers, and which species are most at risk, will allow better targeting of surveillance and control measures.