125,000 cervids tested for Chronic Wasting Disease

As many as 125,000 cervids have been tested at the Norwegian Veterinary Institute (Veterinærinstituttet) since the first wild reindeer was diagnosed with Chronic Wasting Disease - CWD in 2016. The samples come from cervids that were hunted, as well as those found sick or injured in traffic, and testing is an important part of monitoring CWD in Norway.

Testing such large numbers of cervids was possible thanks to an impressive effort from active hunters, municipal game management, the national wild reindeer board, its municipal wild reindeer committees, the Norwegian Environment Agency, the Norwegian Food Safety Authority, local mountain boards and others who submit samples.

Minister of Agriculture and Food Olaug Bollestad (KrF) praises the efforts of the hunters and all others who have supported this national effort.

Minister of Agriculture and Food Olaug V. Bollestad.
I am impressed by the pace the Veterinary Institute has been able to maintain, and the number of samples they have processed so far, says Minister of Agriculture and Food Bollestad. Credit: Torbjørn Tandberg

- I am impressed by the pace the Veterinary Institute has been able to maintain, and the number of samples they have processed so far. Cervid game is a excellent basis for business development, based on hunting experiences and venison type produce, which is a fantastic food source. Therefore we need to monitor the health of the various cervid species, in order to track the spread of CWD. Quick test results are important to hunters, local processing facilities and the culinary supply business, says Minister Bollestad.

Important to get samples from both the brain and lymph nodes

Senior researcher and CWD coordinator Jørn Våge at the Veterinary Institute, says that the need for monitoring is still present. In September 2020, the Veterinary Institute discovered one case of CWD in one wild reindeer harvested during the regular hunt on the Hardangervidda mountain plateau.

Example of what the samples from the brain (left) and lymph nodes should look like.
Example of what the samples from the brain (left) and lymph nodes should look like. Credit: Veterinary Institute

Våge emphasizes that it is important to get samples from both the brain and lymph nodes, and also to maintain high sample quality in order to obtain swift and certain results.

- Thorough sampling and correct labeling with relevant data is key. The aim is to learn more about the spread of the disease, enabling the authorities to manage the disease and our cervid stock in the best possible way, says Våge.

The samples are shaken, to liquify them before they can be properly processed.
The samples are shaken, to liquify them before they can be properly processed. Credit: Veterinary Institute

Intense lab efforts

Sylvie Benestad, responsible for analysis, diagnostics and research on prion diseases at the Veterinary Institute, says that the special laboratory in 2020 and until March this year, has examined more than 25,000 samples from cervids. She is also responsible for the Veterinary Institute's function as the national reference laboratory for prion diseases in animals in Norway, as well as for the international CWD reference laboratory for the World Animal Health Organization (OIE). The reference function for OIE means that the Veterinary Institute is to collaborate with countries all over the world to confirm CWD diagnoses.

- Every day, all year round, we analyze several samples from different animals for prions.

Department engineer Clarita Larsen takes a small part from the sample material that the hunters have submitted.
Department engineer Clarita Larsen takes a small part from the sample material that the hunters have submitted. Credit: Veterinary Institute

The hunting season is always the busiest period, and requires a departmental team effort. At its busiest, we process up to 1600 samples a day. Sample analysis is an extensive process, requiring many steps before arriving at the final test results, says Benestad.

What is prion disease?

CWD is a prion disease, where misfolded protein accumulates in and disrupts normal brain tissue. The disease is one hundred percent fatal for any affected animal. In wild reindeer with classic CWD, it has been observed to be contagious, while the current consensus is that in moose and deer the disease is sporadic.

There has never been an incidence of the disease being transmitted to humans, neither from animals nor from meat, but to be on the safe side, meat from animals that test positive will still not enter the food chain.

The Norwegian Veterinary Institute and the Norwegian Institute for Natural Research (NINA) monitor the incidence of CWD in Norway on behalf of the Norwegian Food Safety Authority and the Norwegian Environment Agency.