REPORT 58/2026 Updated knowledge base on chronic wasting disease (CWD) in Norway veterinary assessment

 REPORT 58/2026 Updated knowledge base on chronic wasting disease (CWD) in Norway veterinary assessment

Updated knowledge base on canine distemper (CWD) in Norway – veterinary assessment

The Norwegian Veterinary Institute has updated the knowledge base on CWD in Norway. The assessment highlights the risk of infection spread, current measures and the need for long-term monitoring. The report was prepared on behalf of the Norwegian Food Safety Authority and is based on new and updated knowledge about scrapie. The Veterinary Institute continues to recommend extensive surveillance and measures to limit the risk of further spread of infection. Download the report https://www.vetinst.no/rapporter-og-publikasjoner/rapporter/2026/oppdatert-kunnskapsgrunnlag-om-skrantesjuke-cwd-i-norge/

REPORT 58/2026 Updated knowledge base on chronic wasting disease (CWD) in Norway – veterinary assessment

1 Summary

This update on chronic wasting disease (CWD) in Norway was prepared by the Norwegian Veterinary Institute in October 2026, at the request of the Norwegian Food Safety Authority. The request sought a veterinary assessment regarding: 1) the current primary pathways for CWD transmission (spread), potential risk-mitigation measures—considered in light of the management objective—and the anticipated consequences of such measures; and 2) the long-term surveillance required to detect new cases of CWD within various cervid populations. Extensive management support has previously been provided through reports from the Norwegian Scientific Committee for Food and Environment (VKM) and earlier recommendations from the Norwegian Veterinary Institute; the knowledge contained therein remains valid. This assessment presents new and updated information from the Norwegian Veterinary Institute that is considered relevant to the management of CWD.

The greatest risk for the spread of CWD is transmission from infected wild reindeer to other reindeer, and secondarily to other susceptible cervids. As of today, Hardangervidda is the only wild reindeer area where infected reindeer have been detected and which still supports a reindeer population. Even after four years without new detections, it remains more likely that some infected animals exist on Hardangervidda than that the population is entirely free of the disease. Over the past four years, at least 1,730 animals (excluding calves) have tested negative for CWD in this area. This provides a high level of confidence that the prevalence of infected animals on Hardangervidda in 2026 is below 0.3% (for example, 12 animals out of a winter population of 4,000). For the largest wild reindeer populations (including the 10 national wild reindeer areas in Norway), a high level of confidence (99%) has now been reached that CWD is not present at a prevalence of 1% or higher. Regarding the possibility of infection at lower prevalence levels—such as the presence of 4 infected animals in a population—there remains significant uncertainty for most wild reindeer areas.

Exposure to prions in the environment is considered the second most important source of CWD transmission. In as-yet unpublished studies, "seeding activity" was detected in soil samples from salt licks in Nordfjella. Most of these detections occurred in Zone 1, though one was also found at a salt lick in Zone 2. The number of detections decreased between 2017 and 2020, and no seeding activity was detected in samples from 2021 or 2024. Given that infected animals have been identified on Hardangervidda, it is reasonable to assume that similar localized environmental contamination may exist there as well, just as it did in Nordfjella.

The consequences of CWD becoming established in Norway are extremely serious; therefore, even a low probability of spread to new areas—or an increase in prevalence within already infected areas—should trigger risk-mitigation measures. The likelihood of CWD spreading can be reduced by limiting population size, decreasing the proportion of males, removing animals that show signs of illness, securing the carcasses of potentially infected animals, and avoiding the “unnatural” congregation of animals in the same location over time—for example, at salt licks. Implementing such measures optimally will be essential to limit the spread of the disease and could, in the best-case scenario, help eradicate CWD from Norway.

CWD surveillance must be conducted over a long period and will be resource-intensive. Highest priority must be given to areas where CWD has been detected, or where there is a high probability of its introduction; in these locations, early detection and improved knowledge regarding prevalence are critical. This applies particularly to Hardangervidda, Nordfjella (zones 1 and 2), other wild reindeer areas within the Nordfjella region, and the Lærdal-Årdal area—which was established using animals from Nordfjella. This also involves continued monitoring of moose, deer and roe deer in the edge zone of the Hardangervidda and Nordella. Furthermore, there remains a need for extensive testing of semi-domesticated reindeer in Southern Norway, due to the potential for transmission from wild reindeer. CWD surveillance would be more effective if animals exhibiting abnormal behavior or clinical signs of disease were more consistently included in testing—this is especially relevant for semi-domesticated reindeer.

Permanent salt licks with soil runoff represent clear sources of infection and are likely significant for the spread of disease both within and between populations of cervids. The use of such salt licks should cease in the peripheral zones surrounding infected areas. They should be replaced by measures that do not encourage animals to congregate or consume soil. We propose that, in the longer term, an assessment be conducted—in collaboration with the relevant stakeholders—that includes a cost-benefit analysis of providing salt to sheep on pasture, as well as an outline of available alternatives.

If the monitoring of reindeer reveals new cases and the prevalence of CWD increases in the Langfjella area, further measures must be considered to prevent the disease from spreading to neighboring wild reindeer populations and other cervids. Such a development would signify the establishment of contagious CWD, and the authorities' objective—to contain and, if possible, eradicate contagious CWD in Norway—would need to be re-evaluated. Given the current situation, we recommend assessing the societal consequences of a permanent establishment of contagious CWD in the Norwegian environment.

In our assessment, the establishment of contagious CWD in Norway would necessitate very extensive, long-term management measures, both locally and nationally.

snip…

6.3.1 Surveillance of the Filefjell, Fram, Vågå, and Lom reindeer management units

For the Filefjell, Vågå, Fram, and Lom reindeer management units, extensive sampling should be conducted to ensure the earliest possible detection of transmissible CWD, should the disease still be present in Nordfjella. This surveillance should be maintained even if these units have achieved a high level of assurance regarding the absence of CWD, as the primary purpose of the surveillance is early warning.

The surveillance should encompass both "risk animals" (animals at higher risk of carrying the disease) and slaughtered animals (older than one year). The approach may be evaluated annually, depending on the progress of reindeer re-establishment in Nordfjella Zone 1. Animals exhibiting abnormal behavior or clinical signs should be recorded, ensuring that data on the "risk animals" examined are available. This will strengthen the credibility of the documentation regarding CWD status, both nationally and internationally.

Consideration may be given to including surveillance for environmental contamination within these reindeer management units. This would be most relevant in Filefjell, specifically at salt licks or feeding sites that are not fenced off. Ideally, the establishment of such sites—where animals congregate—should be avoided. Reindeer enclosures—that is, gathering areas used for activities such as ear-tagging and slaughter—may also serve as appropriate locations for collecting environmental samples.

snip…

Surveillance for CWD should be maintained in Selbu. This is important for establishing a long-term data series in a geographical area where multiple cases of sporadic CWD have been detected. A long-term data series demonstrating that the prevalence of sporadic CWD is not increasing would help reinforce the understanding that sporadic CWD has a spontaneous etiology.

REPORT 58/2026 Updated knowledge base on chronic wasting disease (CWD) in Norway – veterinary assessment

https://www.vetinst.no/rapporter-og-publikasjoner/rapporter/2026/oppdatert-kunnskapsgrunnlag-om-skrantesjuke-cwd-i-norge/_/attachment/inline/9f324a71-ee7e-466f-bccd-7df1e51c73d8:eb1d2f7c783a814eb7cea26e695dec6a335c9907/2026%2058%20Oppdatert%20kunnskapsgrunnlag%20om%20skrantesjuke%20Innspill.pdf

REPORT 58/2026 Updated knowledge base on chronic wasting disease (CWD) in Norway – veterinary assessment

“Exposure to prions in the environment is considered the second most important source of CWD transmission. In as-yet unpublished studies, "seeding activity" was detected in soil samples from salt licks in Nordfjella. Most of these detections occurred in Zone 1, though one was also found at a salt lick in Zone 2. The number of detections decreased between 2017 and 2020, and no seeding activity was detected in samples from 2021 or 2024. Given that infected animals have been identified on Hardangervidda, it is reasonable to assume that similar localized environmental contamination may exist there as well, just as it did in Nordfjella.”

snip…

Permanent salt licks with soil runoff represent clear sources of infection and are likely significant for the spread of disease both within and between populations of cervids. The use of such salt licks should cease in the peripheral zones surrounding infected areas. They should be replaced by measures that do not encourage animals to congregate or consume soil.

snip…

6.3.1 Surveillance of the Filefjell, Fram, Vågå, and Lom reindeer management units

For the Filefjell, Vågå, Fram, and Lom reindeer management units, extensive sampling should be conducted to ensure the earliest possible detection of transmissible CWD, should the disease still be present in Nordfjella. This surveillance should be maintained even if these units have achieved a high level of assurance regarding the absence of CWD, as the primary purpose of the surveillance is early warning.

The surveillance should encompass both "risk animals" (animals at higher risk of carrying the disease) and slaughtered animals (older than one year). The approach may be evaluated annually, depending on the progress of reindeer re-establishment in Nordfjella Zone 1. Animals exhibiting abnormal behavior or clinical signs should be recorded, ensuring that data on the "risk animals" examined are available. This will strengthen the credibility of the documentation regarding CWD status, both nationally and internationally.

Consideration may be given to including surveillance for environmental contamination within these reindeer management units. This would be most relevant in Filefjell, specifically at salt licks or feeding sites that are not fenced off. Ideally, the establishment of such sites—where animals congregate—should be avoided. Reindeer enclosures—that is, gathering areas used for activities such as ear-tagging and slaughter—may also serve as appropriate locations for collecting environmental samples.

snip…

***> “ Surveillance for CWD should be maintained in Selbu. This is important for establishing a long-term data series in a geographical area where multiple cases of sporadic CWD have been detected. A long-term data series demonstrating that the prevalence of sporadic CWD is not increasing would help reinforce the understanding that sporadic CWD has a spontaneous etiology.”

***> remember that…terry

https://www.vetinst.no/rapporter-og-publikasjoner/rapporter/2026/oppdatert-kunnskapsgrunnlag-om-skrantesjuke-cwd-i-norge/

The surveillance programme for Chronic Wastng Disease (CWD) in free-ranging and captive cervids in Norway 2025 to 2016 Singeltary Review

Norwegian Veterinary Institute 3/17

Summary

A total of 11,612 samples of wild, semi-domesticated and captive Norwegian cervids were analysed in 2025. Of these, three moose (Alces alces) tested positive for CWD. All were old females culled in Folldal (20 years old), Tvedestrand (17 years old) and Selbu (16 years old) municipalities. The later case was a traffic injury. The cases detected showed disease characteristics previously described for the species in previous reports, i.e. PrPSc was only detected in brain tissue, and no prions were detected in lymphoid tissues with diagnostic tests (ELISA and western blot). In the Nordic countries, CWD has shown sporadic appearance in moose and red deer, whilst in reindeer the disease has been contagious and with lymphoid detections in routine diagnostics.

Introduction

Chronic Wasting Disease (CWD) was for the first time detected in Europe in 2016, in Norway [1]. This was also the first detection of a natural CWD infection in reindeer (Rangifer tarandus) worldwide. The index case in reindeer was in Nordfjella management area in Southern Norway. All subsequent positive reindeer until 2020 were found in this area (Figure 1). The Nordfjella sub-population was eradicated in 2018 [2]. In 2020, one reindeer CWD case was discovered at Hardangervidda, which is the neighboring area/population to Nordfjella. Another case in reindeer was detected at Hardangervidda in 2022. CWD is a transmissible spongiform encephalopathy (TSE) or prion disease of cervids [3]. It is an invariably fatal neurodegenerative disease. Well-known in North America, CWD has since the 1960’s gradually spread to an increasing number of states and provinces (July 2025: 36 states in USA and five provinces in Canada), both in captive and free-ranging cervids [4]. The republic of Korea has also diagnosed the disease after importation of infected elk (Cervus elaphus nelsoni) from Canada [5]. Following the emergence of CWD in Norway, reindeer were identified as a naturally susceptible species. Norway has by now three affected species; reindeer, moose (Alces alces) and red deer (Cervus elaphus). CWD in the Nordic cervids has shown different epidemiological paterns according to species. In routine diagnostics (ELISA and western blot) reindeer have detectable prions both in brain and lymphoid tissues, whilst moose and red deer cases only in the brain. The tissue- and geographic distribution suggests a contagious character of the disease in reindeer. The disease in moose and red deer occurs sporadically, has only been found in older animals, and there is litle evidence for contagiousness and horizontal spread between live animals. Since 2018, old female moose has also been diagnosed with sporadic CWD in Finland and Sweden [6,7].

Four cervid species are prevalent in natural free-ranging populations in Norway: moose, red deer, roe deer (Capreolus capreolus) and reindeer. Red deer predominates along the west coast, whereas moose and roe deer mainly inhabit other areas of the country. The wild reindeer is found in fragmented sub-populations in the remote alpine regions of Southern Norway [8]. The official numbers (February 2026) of hunted cervids were in the 2025 season: 25,951 moose, 49,449 red deer, 27,173 roe deer and 3,851 wild reindeer [9] In addition, Norway has populations of semi-domesticated reindeer that live in a herded condition, though free ranging and migrating between summer- and winter-feeding areas. Most semi-domesticated reindeer are found in the Northern part of Norway as part of the Sami culture, particularly in the county Finnmark, and the total population counts about 250,000 animals [10]. There are approximately 100 deer farms in Norway; most of them keep red deer, but some farms have fallow deer (Dama dama) and occasionally both species.

Testing wild cervids for CWD was initiated in 2002 through the National Health Surveillance Program for Cervids and muskox (Ovibos moschatus), operated by the Norwegian Veterinary Institute (NVI) on behalf of the The surveillance programme for Chronic Wasting Disease (CWD) in free-ranging and captive cervids in Norway 2025 Norwegian Veterinary Institute 4/17 Norwegian Environmental Agency. From 2003, a passive surveillance programme for CWD has been in place in Norwegian wild and captive cervids. The programme is coordinated by NVI and financed by the Norwegian Food Safety Authority (NFSA). In addition, the programme includes testing samples from slaughtered semi-domesticated reindeer from several regions of the country. In 2006 and 2007 the European Commission (decision 2007/182/EC) initiated a survey for CWD where Norway took part, like the EU member-states, testng 700 cervids. A similar testing was performed in EU in the years 2018-2020 (reg. 2017/1972), covering six member states in addition to Norway. Shown in Table 1 is the total number of cervids tested for CWD in Norway from 2002-2025.

Since there is no separate program to report surveillance of TSE in Muskox, such testing is included in this publication. TSE has never been reported in the species.

Aim

The aim of the program is to document the occurrence of CWD in the Norwegian cervid populations.

Materials and methods…

snip…

Discussion

In 2016, CWD was for the first time detected in Europe, in six free-ranging cervids in Norway. In total, the CWD testing revealed 21 reindeer, 17 moose, and three red deer with the disease in the period 2016-2025. The first 19 reindeer cases were detected within the outbreak zone 1 of Nordfjella wild reindeer management area. The affected population was culled in 2018. Two additional cases have been diagnosed in reindeer hunted at Hardangervidda in September 2020 and September 2022. This last discovery of CWD in a second reindeer area challenges the prospect of eradicating the contagious disease in the reindeer populations. While the eradication of the Nordfjella sub-population was aimed to eliminate the local outbreak, subsequent findings have highlighted new epidemiological challenges. Hardangervidda holds the largest sub-population of wild reindeer in Europe. Compared with Nordfjella, the area is far less suitable for containment of the disease.

Nevertheless, so far, no additional reindeer cases have been detected outside Nordfjella and Hardangervidda despite the testing of more than 98,000 reindeer. In the absence of additional detected cases, probabilistic modelling has therefore been applied to assess the likelihood of disease freedom across different areas. This indicates a limited infection in this species. Nevertheless, the probability of freedom as estimated using scenario tree modelling varies a lot between different wild reindeer management areas or semi-domesticated reindeer districts depending on population size and number of tested animals per area or district. From the extended surveillance of cervids, there is a confidence that CWD is not present at high prevalence (5%) in cervids in Norway [16]. For a lower prevalence (below 1%), there is less confidence. Only a few wild reindeer management areas have obtained a 95% probability of freedom for a design prevalence of 0.5% [17]. The Norwegian Veterinary Institute provide central management authorities with modelling of freedom probability in areas within restriction zones of CWD. Under the modelling assumptions of a design prevalence of 4 (i.e. that the probability of absence of CWD is calculated as the probability of finding at least one CWD-infected animal if there are 4 CWD-infected animals in the population), Hardangervidda and Nordfjella management areas have obtained 41 % and 99 % respectively, post hunting season in 2025. The reindeer district of Filefjell, with around 3000 semi- domesticated reindeer during the winter (post slaughter) and sharing (a fenced) border at summer pasture to the Nordfjella area, has obtained a high probability of freedom for a design prevalence less than 0.5 % [18].

Analysis of surveillance data from Norwegian and Swedish semi-domesticated reindeer districts used a scenario tree model, and at the national level the mean probability of disease freedom was 87.0 % in Norway by 2021 [19].

Beyond prevalence estimates, insight into disease characteristics across species is further informed by prion strain characterisation. Further research studies have shown that the strain found in reindeer is different from those of the two other cervid species. The reindeer cases were indistinguishable, in results of diagnostic test methods, from cases of CWD from North America. The positive European moose and red deer have shown characteristics of sporadic distribution [6,7,14], with no detectable prions in the lymphoid tissues using diagnostic tests, in contrast with the reindeer and cervids from North America. Although routine diagnostics primarily define these species differences, complementary research methods (PMCA) showed low detectable levels of PrPSc also in peripheral tissues [20] from moose and red deer. Inoculation studies in rodents demonstrated multiple strains among the Norwegian cases, across three species, all different from North American cases. Nevertheless, the reindeer strain has many similarities with strains isolated from cases from North America [21,22] and is expected to harbor similar epidemiological properties.

https://www.vetinst.no/overvaking/chronic-wasting-disease-vilt-cwd/_/attachment/inline/701c0cc5-1708-484a-8b89-779661e7080e:0b97daa380fbd88031c6d2fe58726cacd3e00dcf/2026_17_OK_CWD%20in%20Norway%202025%20KOMPLETT.pdf

please note;

We call scrapie for «skrapesyke».

We call CWD for «skrantesyke».

«Skrante» have a meaning similar to «wasting».

Norway CWD 2025 Update

2025

A total of 11,612 samples of wild, semi-domesticated and captive Norwegian cervids were analyzed in 2025. Of these, three moose (Alces alces) tested positive for CWD. All were old females culled in Folldal (20 years old), Tvedestrand (17 years old) and Selbu (16 years old) municipalities. The later case was a traffic injury.

The cases detected showed disease characteristics previously described for the species in previous reports, ie PrPSc was only detected in brain tissue, and no prions were detected in lymphoid tissues with diagnostic tests (ELISA and western blot). In the Nordic countries, CWD has shown sporadic appearance in moose and red deer, whilst in reindeer the disease has been contagious and with lymphoid detections in routine diagnostics. Download the report

Chronic wasting disease 2025 (pdf 2mb)

https://www.vetinst.no/en/surveillance-programmes/chronic-wasting-disease

Download report

Chronic wasting disease 2025 (pdf 2mb) Previous reports

Chronic wasting disease 2024 (pdf 3mb) Chronic wasting disease 2023 (pdf 2mb) Chronic wasting disease 2022 (pdf 4mb) Chronic wasting disease 2021 (pdf 5mb) Chronic wasting disease 2020 (pdf 5mb) Chronic wasting disease 2019 (pdf 5mb) Chronic wasting disease 2018 (pdf 3mb) Chronic wasting disease 2017 (pdf 2mb) Chronic wasting disease 2016 (pdf 4mb) Chronic wasting disease 2015 (pdf 1mb) Chronic wasting disease 2014 (pdf 539kb) Chronic wasting disease 2013 (pdf 1mb) Chronic wasting disease 2012 (pdf 1mb) Chronic wasting disease 2011 (pdf 904kb) Chronic wasting disease 2010 (pdf 616kb) Chronic wasting disease 2009 (pdf 530kb) Chronic wasting disease 2008 (pdf 497kb) Chronic wasting disease 2007 (p. 103) (pdf 6mb) Chronic wasting disease 2006 (p. 109) (pdf 3mb) Chronic wasting disease 2005 (p. 105) (pdf 4mb)

https://www.vetinst.no/en/surveillance-programmes/chronic-wasting-disease

Norway cwd skrantesjuke

https://www.vetinst.no/nyheter/skrantesjuke-er-fortsatt-en-alvorlig-helsetrussel-for-hjortedyr

https://apps.vetinst.no/skrantesjukestatistikk/#kasus

https://apps.vetinst.no/skrantesjukestatistikk/#omrade

https://apps.vetinst.no/skrantesjukestatistikk/#aar

https://apps.vetinst.no/skrantesjukestatistikk/#materiale

https://apps.vetinst.no/skrantesjukestatistikk/#psu

https://apps.vetinst.no/skrantesjukestatistikk/#om

https://apps.vetinst.no/skrantesjukestatistikk/#kasus

THURSDAY, OCTOBER 22, 2026

The surveillance programme for Chronic Wasting Disease (CWD) in free-ranging and captive cervids in Norway 2025 to 2016 Singeltary Review

https://prpsc.proboards.com/thread/261/norway-prion-update-singeltary-review

https://chronic-wasting-disease.blogspot.com/2026/10/the-surveillance-programme-for-chronic_01710964279.html

TSS