BC CWD Program Report 2019-20 - Prepared by: Cait Nelson and Helen Schwantje GIS maps by: Shari Willmott - Province of British ...
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BC CWD Program Report 2019-20
Prepared by: Cait Nelson and Helen Schwantje
GIS maps by: Shari Willmott
INTRODUCTION
Chronic wasting disease (CWD) is an infectious and degenerative disease of the central nervous system
that affects species of the deer family (cervids). CWD belongs to a family of diseases called transmissible
spongiform encephalopathies (TSEs) which are caused by abnormal proteins called “prions” and include
diseases such as bovine spongiform encephalopathy (i.e. “mad cow disease”), scrapie in sheep and
goats, and Creutzfeldt-Jakob disease in humans. These diseases are generally species specific and there
is no direct evidence that CWD is transmissible to humans. Although many details about the disease
remain unknown, much has been learned through research and experience over the last 3 decades. See
research highlights for 2019-20 in Appendix 3.
CWD is fatal in all cases and there is no vaccine or treatment. Most cervids that test positive appear
healthy and are often hunter harvested animals. Since the disease has a long incubation period,
symptoms can take over a year to develop after infection. In later stages of the disease, signs can
include weight loss, behavioral changes, drooling and poor coordination.
As of May 2020, CWD has been confirmed in captive and/or free-ranging cervids in 26 US states, 3
Canadian provinces, South Korea and Europe. CWD has not been detected in British Columbia (B.C.).
Wildlife managers worldwide consider CWD a high priority because of its impact on cervid populations
and hunting. No effective disease control exists. Experts have developed guidelines for comprehensive
regional and national strategies for CWD surveillance and management, such as the Association of Fish
and Wildlife Agencies Technical Report on Best Management Practices for CWD, which recommends
that CWD-free jurisdictions focus on preventing the entry of the disease. Collaboration amoung
jurisdictions is resulting in better communication and more consistency with legislative and regulatory
tools to support CWD surveillance, response and prevention. B.C. is a member of the North American
CWD Task Force (CWDTF), formed in 2020 to foster cross-jurisdictional strategies and coordination of
efforts.
The diagnosis of CWD positive deer and moose near Libby, Montana increases B.C.’s risk for CWD
significantly. Montana Fish, Wildlife and Parks (FWP) reported a disease prevalence of 13% in
whitetailed deer within the city of Libby from 2019 surveillance, suggesting CWD presence for at least
several years. Montana, similar to other jurisdictions, has many challenges with this disease in different
ecosystems, so they are revising their CWD management and regulatory measures and continue to
collaborate with B.C. and other CWDTF members.
The B.C. CWD Program developed and follows the framework outlined in the Surveillance and Response
Plan for Chronic Wasting Disease in British Columbia (2019) which is based on 3 principles; Prevention,
Surveillance and Preparedness. The Provincial CWD Advisory Committee and Regional Working Groups
in Kootenay and Peace Regions membership (both include staff, other ministries, First Nations,
stakeholders and local businesses) continue their involvement and support and provide input on CWD
Program activities and planning. Annual meetings with the Regional CWD Working Groups and the
Provincial CWD Advisory Committee were held in January 2020 and May 2020, respectively. Action
items from these meetings are summarized in Appendix 1.
1
PREVENTION
The B.C. CWD Program, with expert advice from partners, has assessed the risk of CWD entering B.C.
The most likely risk is human importation of a CWD infected cervid carcass or tissues from a CWD
positive location. Degradation of carcasses or tissues infected with CWD can contaminate the
environment, with prions directly binding to soil particles. The prions can persist for years, possibly
decades, and are resistant to any practical method of destruction. The contaminated environment has
the potential to infect healthy cervids through consumption of soil or vegetation. Confirmation that
CWD is now present in free-ranging cervid populations in northwest Montana, only 60 kms from the B.C.
border and within the natural range of cervid movements, presents a new risk of disease entry through
live infected cervids moving into B.C. CWD surveillance in Alberta where mule deer are the primary host,
confirms the disease is moving westward towards the B.C. border from southcentral Alberta.
Mitigation of this risk has been partially accomplished with Wildlife Act regulations including; prohibition
on the importation of live cervids, prohibition on the importation of high-risk parts of harvested cervids,
and prohibition on the use of attractants and scents made from cervid materials such as urine. However,
awareness and compliance with the regulation requires education and outreach to all hunters. B.C.
residents continue to participate in out of province hunts, returning with intact carcasses or high-risk
materials. Communication with these hunters for proper disposal of high-risk materials has indicated a
lack of awareness of the disease and precautionary measures. It has also confirmed a lack of effective
methods and infrastructure for disposing of these high-risk biological materials.
Figure 1: CWD graphic for highway signs.
SURVEILLANCE
Surveillance is a critical component of disease detection. Since 2002, the B.C. CWD Program has
conducted surveillance and outreach activities in target areas of the province, with no positive cases.
B.C.’s surveillance objectives are to confirm CWD status (in free-ranging cervid populations) and if
introduced, to detect the disease as soon as possible at the lowest possible prevalence. Target
surveillance areas are based on risk factors and continue to focus on regions adjacent to jurisdictions
with positive cases (Alberta and Montana) and areas with clinically suspect cases. Prior to 2019 B.C. was
considered low risk for the presence of CWD. With cases now in northwest Montana, continued
westward spread across Alberta and an increase of high-risk material (i.e. intact cervid carcasses)
entering the Province, surveillance effort has increased in the highest risk areas.
A positive CWD diagnosis can only be made from specific tissues collected from the head of a cervid
(samples tested vary with the cervid species, see below). The B.C. CWD Program will accept heads from
any cervid species collected from anywhere in the province. Priority is given to cervids exhibiting
symptoms and road killed cervids as the most likely to be positive, followed by any cervid harvested or
collected in a high-risk area. Heads are generally collected and sampled by Wildlife Health staff or
2
trained biologists. Sample tissues are collected, processed and submitted to the Canadian Wildlife
Health Cooperative laboratory in Saskatoon, Saskatchewan for immunohistochemistry. Retropharyngeal
lymph nodes (RPLNs) and tonsils are collected from deer. RPLNs and obex are collected from moose, elk
and caribou. All tissues are fixed in 10% buffered formalin, with a portion retained (frozen) as a back-up
sample if re-testing is required.
Submission of cervid heads for CWD testing is voluntary in most areas of the province. However, in
response to the detection of CWD in Libby, Montana, on the request of the CWD Program, the B.C.
Ministry of Agriculture issued a General Order (Animal Health Act) in 2019 (and again in 2020) for
mandatory submission of the heads of mule deer and white-tailed deer harvested in management units
(MUs) 4-1 through 4-7 in the 2019 hunting season. Once samples are processed and tested, CWD results
are posted to the B.C. CWD website: www.gov.bc.ca/chronicwastingdisease
In 2019-20, the B.C. CWD Program submitted 1260 samples for testing. See below for an overview of
samples numbers by wildlife management region.
Figure 2: Provincial overview (by region) of CWD samples testing in 2019-20.
3
Hunters submitted 88% of the 2019 samples. The remaining were sourced from road kills, mortalities
and conservation officers. See below samples by source, by species and by sex.
Samples by Source
0 200 400 600 800 1000 1200
HUNTER 1109
ROAD KILL 53
CONSERVATION OFFICER 59
MORTALITY 13
SOURCE NOT RECORDED 28
Figure 3: Number of CWD samples by source.
Samples by Species
0 200 400 600 800 1000
CARIBOU 8
ELK 94
MOOSE 62
WHITE-TAILED DEER 903
MULE DEER 177
BLACK-TAILED DEER 16
SPECIES NOT RECORDED 4
Figure: 4: Number of CWD samples by species.
Samples by Sex
0 200 400 600 800 1000
FEMALE 393
MALE 846
SEX NOT RECORDED 25
Figure 5: Number of CWD samples by sex.
4
1069 samples (85% of total) and 144 samples (11% of total) were submitted from the Kootenay and the
Peace Regions, respectively. See below for regional overview by MU.
Figure 6: CWD samples from Kootenay Region (2019-20) by wildlife management unit.
Figure 7: CWD samples from Peace Region (2019-20) by wildlife management unit.
PREPAREDNESS
If CWD is confirmed in a B.C. cervid population, an effective response will require a team effort. The B.C.
CWD Program will work collaboratively with government and the Provincial CWD Advisory Committee
and Regional Working groups according to the Surveillance and Response Plan. A network approach and
an informed public is expected to help support initial response activities to minimize negative impacts to
5
cervid populations and potentially eradicate the disease. Response to a positive diagnosis will be
managed through an Incident Command System (ICS), led by the Provincial Wildlife Veterinarian and
informed by established partnerships. See Appendix 4 for an ICS template. These steps, in general, are
outlined in the Surveillance and Response Plan. The initial response phase will gather the required
information to assess risk and determine next steps.
SUPPORTING ACTIVITIES
The B.C. CWD Program and partners must continue to focus on improving the awareness of CWD, the
reduction of risks and targeted surveillance where required. Effective and appropriate outreach is a key
element. Those resources are developed collaboratively by B.C. CWD Program and disseminated
through the B.C. CWD website (www.gov.bc.ca/chronicwastingdisease), the B.C. Hunting and Trapping
Regulations Synopsis, partner websites and social media (eg. B.C. Wildlife Federation and others),
presentations, workshops, printed material, highway signs and other means. Outreach activities have
focused on the hunting public and First Nations communities, but resources are available for anyone.
In 2019-20, emergency investments by Government and external partners, especially the Habitat
Conservation Trust Foundation and the B.C. Wildlife Federation, provided infrastructure to support
enhanced outreach and surveillance activities in the Peace and Kootenay Regions. Regional CWD
Program coordinators (contracted through BCCF) were key to local delivery and remain essential to
successful program delivery in the Peace and Kootenay Regions. Each coordinator has supplied summary
reports with recommendations for improvement of program delivery. A list of recommendations for
improved program delivery in 2020-21 is included in Appendix 2.
Figure 8: CWD coordinator Brian Paterson at Sportsmen Show (March 2020).
Figure 9: BC CWD freezer / drop off location for head collection program (donated by BCWF).
CONCLUSION
CWD has not been detected in B.C. but the risk of entry continues to increase. This disease has been
very costly and difficult, if not impossible, to manage in other jurisdictions. It is critical that B.C.
continues its proactive actions to remain CWD free.
The disease was not detected in the highest risk areas despite enhanced surveillance activities in 2019-
20. Actions taken, including the General Order (Animal Health Act), increased focused outreach, and
involvement of First Nations and stakeholders, resulted in a significant increase in samples collected in
the highest risk area along the BC-Montana border from 2018-19 (N=99) to 2019-20 (N=1069). 2019-20
6surveillance results, while improved, do not confirm the absence of CWD. If the disease was present in
this area (i.e. mandatory MUs) at a prevalence of 0.52% (white-tailed deer) and 3.4% (mule deer) or
greater, with the number of samples tested, at least one case would have been detected (at a 95%
confidence). Sustained enhanced surveillance in this area is required to maintain confidence that cervid
populations are CWD-free. To accomplish this, the BC Ministry of Agriculture has again issued a General
Order for mandatory submission of mule deer and white-tailed deer harvested in management units
(MUs) 4-1 through 4-7 in the 2020 hunting season.
In this past year, new challenges were identified including; an increased disease distribution and
prevalence in Alberta and Montana, an increase in hunters returning to B.C. with intact carcasses or
high-risk materials and dumping of high-risk materials in the environment as well as an overall lack of
awareness of these risks. The solutions to these issues include newly focussed outreach products for
more audiences that include First Nations and improved access to appropriate methods of disposal of
high-risk materials, particularly in high risk areas.
Support and participation from hunters and communities is excellent, but there is much more that can
be done. The B.C. CWD Program will continue to work with experts and partners towards strengthening
B.C.’s preventative measures and preparedness to protect B.C. cervid populations from the threat of
CWD.
7APPENDIX 1: Action Items from 2020 Working Group and Advisory Committee Meetings
BC CWD Program Action Items
Peace • CWD presentation/workshop for Saulteau and West Moberly First Nations
Region • CWD content for First Nations outreach/social media/newsletter
Working • Doig River First Nation will present CWD at a community meeting and request
Group permission to use community freezer for samples
Meeting • Doig River First Nation will include CWD material in monthly newsletter
January • CWD Program staff to attend BC Cattlemen’s AGM
23, 2020
• Develop Best Management Practices for carcass handling and disposal – for
hunters
• Develop disposal plan with Peace River Regional District, MOTI, others
• Invite representative from MOTI and Peace River Regional District to working
group
• Supply Saulteau/West Moberly freezer location with supplies and posters
• Investigate new freezer location at Corlane’s
• Update hunting/trapping synopsis on the website to include drop off locations
• Develop road kill collection system with Doig River First Nation
• Produce signs for crews collecting road kills
• Investigate development of road kill app
• Develop road kill collection system with MOTI and contractors
• Develop regional specific budget request for 2020-21
Kootenay • Increase awareness of sample collection program and ensure instructions at
Region freezers are clear
Working • Develop communications and printed material for target audience with focus
Group on risks and Best Management Practices
Meeting • Develop outreach / communications strategy (with schedule / important dates)
January and prepare press release
29, 2020 • Working Group members to disseminate outreach materials / communications -
provided by Cait
• Develop Best Management Practices for carcass handling and disposal – for
hunters
• Develop disposal plan with municipalities, MOTI, others
• Discuss risk of human exposure to prions in the environment with Public Health
working group
• Working Group to prepare a joint statement for improved regulatory tools
for CWD
• Develop road kill collection system with MOTI and contractors
• Develop tracking system/tag with trappers/EKTA
• Develop regional specific budget request for 2020-21
Provincial • Follow up with BCWF app developers at UBC Kelowna and investigate various
CWD wildlife apps
Advisory • Develop communications for BC hunters that hunt in Alberta/Saskatchewan
Committee • Develop business case and outreach to MOTI executive and district offices – to
Meeting
improve access to road kills
May 26,
• MOTI to provide contacts for annual Roadbuilders meeting, regional MOTI and
2020
maintenance contractors
8Continued...
• Deliver outreach to COS regarding access to euthanized animals
• Committee to coordinate communications related to General Order (mandatory
submissions) in Kootenay Region
• Seek funding and partners for purchase of incinerators
• Finalize outreach materials and circulate to committee for input
• Propose meeting to discuss CWD management scenarios
• Request collaborators for white-tailed deer movement study between
BC/Alberta/Montana/Idaho
• Develop business case and funding request for in-province CWD testing
9APPENDIX 2: Recommendations from Regional CWD Program Coordinators
Regional CWD Coordinator Recommendations for 2020-21
Peace Region • Increase participation of road maintenance contractors.
Provided by: • Hire 2-3 locals to collect roadkill on a stipend or similar basis.
Brian Paterson • Develop and obtain signage for coordinator collecting roadkill cervid heads.
• Determine buy-in for provincial roadkill application for smart phones/mobile
devices.
• Increase partnerships with First Nations communities.
• Establish sample drop-off locations at local hunting stores.
• Deliver regional CWD training for FLNRORD biologists.
• CWD information included with BCEID e-licensing.
• Include BC Wildlife Health phone number in CWD section of regulations
synopsis.
• Region specific informational CWD business cards or handouts at tag/license
vendors.
• Increase use of social media for CWD outreach.
• BC CWD Program attendance at Sportsmen shows.
• Game checks with COS and First Nations.
• Consider incentive programs, local draws, prizes.
Kootenay Region • Focus on engaging with stakeholder groups, members of the public and First
Provided by: Nations to increase awareness regarding potential vectors (carcasses,
Jeff Berdusco scents, CWD positive meat, etc…).
• Develop and support a strong hazardous material transport protocol for
known affected or CWD positive animals/meat.
• Create video(s) to be posted on the web and social media showing proper
cervid sample preparation, tagging and submission.
• Construct shelters for freezers or move to covered locations.
• Create a position or add responsibility to MOTI contractors to manage road-
kill samples (currently out of scope for MOTI contractors).
• Work towards more awareness and support from different points of contact
for road-kill samples (namely the Conservation Officer Service, RCMP and
Trappers) for “year-round” sample submission.
• Partner with First Nations to develop and deliver indigenous specific
CWD/wildlife health outreach and messaging.
10APPENDIX 3: THE LATEST IN CWD RESEARCH, SCIENCE AND MANAGEMENT
Predicting Spread-Risk Potential of Chronic Wasting Disease to Sympatric Ungulate Species
Cullingham et al 2020
As CWD continues to expand, additional wild ungulate species including bison, bighorn sheep, mountain
goat, and pronghorn antelope may be exposed. To better understand the species barrier, the current
literature on taxa naturally or experimentally exposed to CWD was reviewed to identify susceptible and
resistant species. Findings suggest the host range for CWD will potentially include pronghorn, mountain
goat and bighorn sheep, but bison are likely to be more resistant. These findings highlight the need for
monitoring potentially susceptible species as CWD continues to expand.
Control and Surveillance Operations to Prevent Chronic Wasting Disease Establishment in Free-
Ranging White-Tailed Deer in Québec, Canada
Gagnier et al 2020
The first cases of CWD in Québec were detected in 2018 on a red deer (Cervus elaphus) farm.
Immediately following detection, intensive culling efforts were conducted in a control area around the
infected farm. To prevent the spread of CWD, Quebec applied legal restrictions regarding the movement
of specific anatomical parts of cervids harvested near the affected farm. To determine if CWD was
present in free-ranging cervids, over 3000 harvested white-tailed deer (Odocoileus virginianus) and 534
culled white-tailed deer were tested. No positive CWD cases were found, suggesting that if the disease is
present in free-ranging animals, infection rates are low, and it may still be possible to prevent its
establishment in Québec.
Cross-validation of the RT-QuIC Assay for the Antemortem Detection of Chronic Wasting Disease in Elk
Haley et al 2020
Conventional diagnosis relies on tissues collected post-mortem; however, recent research has focused
on newly developed amplification techniques using samples collected antemortem. The present study
sought to cross validate the real-time quaking-induced conversion assay (RT-QuIC) evaluation of rectal
biopsies collected from an elk herd with endemic CWD. A significantly higher number of positive
samples were identified using RT-QuIC, with results seemingly unhindered by low follicle counts. These
findings support the continued development and implementation of amplification assays in the
diagnosis of prion diseases, targeting not just antemortem sampling strategies, but post-mortem testing
approaches as well.
Revisiting Hunter Perceptions toward Chronic Wasting Disease: Changes in Behavior over Time
Holland et al 2020
Hunters play a vital role in the management of wildlife diseases such as Chronic Wasting Disease, but
their harvest rates may change based on their perception of disease risk. The objective was to estimate
how hunter harvest may change over time based on perception of disease and proximity to disease
location. We found that hunters harvested fewer deer in the 4 years following disease discovery but that
in the next 4-year period harvest rates increased to be similar to those from before the discovery of the
disease. This indicates that changes in behavior due to disease presence may diminish over time.
An empirical analysis of hunter response to chronic wasting disease in Alberta
Pattison-Williams et al 2020
11An integral partner in CWD management is the hunting community. This article empirically explored the
response of Alberta mule deer hunters to CWD by modeling license application trends in areas where
CWD has been positively detected in wild cervids. Results indicated that hunters are continuing to apply
to hunt mule deer in areas with CWD and this relationship is not statistically impacted by the increasing
prevalence of CWD. This outcome may be because CWD prevalence in Alberta is relatively low (but
increasing), which is consistent with the literature indicating that few hunters avoid CWD zones until
prevalence increases dramatically. Results also suggest that hunter-based strategies remain effective
options for management.
Chronic Wasting Disease Modelling: An Overview
Winter and Escobar 2020
To update the research community regarding the status quo of CWD epidemiologic models, a meta-
analysis on CWD research was conducted and explored the analytical methods used historically to
understand CWD. CWD modeling was initiated in the early 2000s and has increased since then. Studies
focused primarily on regression and compartment model–based models, population-level approaches,
and host species of game management concern. Similarly, CWD research focused on single populations,
species, and locations, neglecting modeling using community ecology and biogeographic approaches.
Chronic wasting disease detection relied on classic diagnostic methods with limited sensitivity for most
stages of infection. Past modeling efforts generated a solid baseline for understanding CWD in wildlife
and increased our knowledge on infectious prion ecology. Future analytical efforts should consider more
sensitive diagnostic methods to quantify uncertainty and broader scale studies to elucidate CWD
transmission beyond population-level approaches. Considering that infectious prions may not follow
biologic rules of well-known wildlife pathogens (i.e., viruses, bacteria, fungi), assumptions used when
modeling other infectious disease may not apply for CWD. Chronic wasting disease is a new challenge in
wildlife epidemiology.
Inactivation of chronic wasting disease prions using sodium hypochlorite (bleach)
Williams et al 2019
Hunters, meat processors and others in contact with tissues from potentially CWD-infected cervids need
a practical method to decontaminate knives, saws and other equipment. Prions are notoriously difficult
to inactivate, and most effective methods require chemicals or sterilization processes that are either
dangerous, caustic, expensive or not readily available. Although corrosive, sodium hypochlorite (bleach)
is widely available and affordable and has been shown to inactivate prion agents including those that
cause scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease. In the current study,
bleach was confirmed as an effective disinfectant for CWD prions at minimum times and bleach
concentrations. A five-minute treatment with a 40% dilution of household bleach was effective at
inactivating CWD seeding activity from stainless-steel wires and CWD-infected brain homogenates.
However, bleach was not able to inactivate CWD seeding activity from solid tissues in our studies.
Chronic wasting disease and implications for cervid populations
Ketz et al 2019
Geographic detection and distribution of CWD notably increased after 2002, although the disease has
been present in North America since at least the 1960s. CWD is characterized by a prolonged course of
individual infection, lengthy epizootics that last for decades, and delayed population effects until after
prevalence has reached a sufficient level. The available literature on CWD was reviewed and synthesized
to assess the current state of the science on disease dynamics and population impacts. The early phase
of a CWD epizootic is characterized by slowly increasing prevalence and geographic spread, but these
eventually accelerate and lead to declines in survival and recruitment that drive population reductions.
The threshold for these population impacts depends on species-specific demography, genetics,
12transmission and numerous factors influencing cervid infection and mortality. As prevalence and spread
continue to accelerate, management actions to mitigate CWD impacts will be challenging, costly and will
likely require changes in how we manage cervid populations.
Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal
Species
Osterholm et al 2019
CWD has been confirmed in at least 26 U.S. states, three Canadian provinces, South Korea, Finland,
Norway, and Sweden, with a notable increase in the past 5 years. The continued geographic spread of
this disease increases the frequency of exposure to CWD prions among cervids, humans, and other
animal species. Since CWD is now an established wildlife disease in North America, proactive steps,
where possible, should be taken to limit transmission of CWD among animals and reduce the potential
for human exposure.
13APPENDIX 4: Incidence Command System (Template)
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