Chronic Wasting Disease Program Standards

2. Trace-back herds – An exposed herd in which a CWD positive animal resided in any of the 60 months before the diagnosis. If the positive animal was a natural addition, the origins of all purchased animals for the previous 60 months should be evaluated to locate a possible source herd for introduction of the CWD infection.

3. Trace-forward herds – A herd that has received exposed animals from a positive herd within 60 months before the diagnosis of CWD in the positive herd or from the identified point of entry of CWD into the positive herd.

4. Any other susceptible animals which may have been exposed to CWD from direct or indirect contact (e.g., exposure to wild cervids).





(4.3) Trace-Back and Trace-Forward Notifications



Trace-back and trace-forward herd owners and their respective State authorities should be notified within 15 business days after their herds are identified as exposed. All notification should be provided in writing to the respective State or States and a copy provided to the AVIC in the corresponding Area Office even if the initial contact was verbal.



If these herds reside in States different than the positive herd, notification will be accomplished through the respective Federal or State official. On notification, actions regarding trace-back and trace-forward herds enrolled in the national CWD HCP should be taken as prescribed in these Program Standards.



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Appendix I. Official Animal Identification



The requirements for Official Animal Identification are described in 9 CFR 55.25.



Each animal required to be identified must have at least two forms of identification attached to its body.

One of the animal identifications must be official animal identification with a nationally unique animal identification number that is linked to that animal in the CWD National Database (SCS Core One – National Instance) or equivalent State database.



The type of official identification device must be approved by APHIS. The devices can be an electronic implant (electronic identification device/EID), legible flank tattoo, legible ear tattoo, tamper-resistant ear tag, or any other device approved by APHIS.



Please note that in accordance with 9 CFR 86.4 (Traceability rule) removal of official identification devices is prohibited except at the time of slaughter, at any location upon the death of an animal, or as otherwise approved by the State or Tribal animal health official or an APHIS area veterinarian in charge when a device needs to be replaced.



In accordance with 9 CFR Part 86.1 (Traceability rule) an official ear tag is defined as an identification tag approved by APHIS that bears an official identification number for individual animals. Beginning March 11, 2014, all official eartags manufactured must bear an official eartag shield. Beginning March 11, 2015, all official eartags applied to animals must bear an official eartag shield. The design, size, shape, color, and other characteristics of the official ear tag will depend on the needs of the users, subject to the approval of the Administrator. The official ear tag must be tamper-resistant and have a high retention rate in the animal.



The official identification number must use one of the APHIS-approved numbering systems to provide a nationally unique identification number. For the purposes of the CWD rule, and in accordance with the Traceability rule (9 CFR 86.1), the official identification number must be a nationally unique number that is permanently associated with an animal and that adheres to one of the following numbering systems:



(1) National Uniform Eartagging System (NUES).

(2) Animal Identification Number (AIN).

(3) Location-based number system

(4) Any other numbering system approved by the Administrator for the identification of animals in commerce.



The device must be applied by the owner of the herd or his or her agent and be linked to that herd in the National CWD Database (SCS Core One – National Instance) or equivalent State database. If a microchip is used and the animals will be slaughtered under State or Federal meat inspection, it should be used in compliance with applicable State or Federal regulations.



The second animal identification must be unique to the individual animal within the herd and also be linked to that animal and herd in the National CWD Database (SCS Core One – National Instance) or equivalent State database. As an example, the unique Animal Identification Number may be used on two separate identification devices on the same animal to fulfill the identification requirements if desired.



Although not required in the CWD rule, it is recommended that all animal identification devices be visible on the animal from an appropriate distance to allow visual verification of the identification number on the device without animal restraint. Any animals in which identification cannot be visually inspected will need some form of restraint for confirmation during herd inventories.



The FDA Center for Veterinary Medicine (CVM) regulates and permits the marketing of implantable transponder devices (Electronic identification devices/EID) for use in animals. Please contact the FDA or the specific manufacturer/ distributor for information on approved EIDs. In addition, USDA’s Food Safety and Inspection Service (FSIS) should be contacted regarding anatomic placement of the EIDs in animals



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that may be presented for slaughter in official slaughter facilities to determine if these devices pose a potential physical food safety hazard.



See APHIS Web site link for additional information on animal identification:

http://www.aphis.usda.gov/traceability/downloads/ADT_eartags_criteria.pdf



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Appendix II. Fencing Requirements and References



The herd premises must have perimeter fencing adequate to prevent entry or exit of cervids. In herd premises already existing at the time of the effective date of the CWD rule, fencing must comply with any existing State regulations or requirements. For herds established after the effective date of the CWD rule, the fence must be a minimum of 2.4 meters (8 feet) high and must comply with any other existing State requirements. At least one study (VerCauteren, et.al 2010) recommends fence height greater than 2.4 meters (at least 10 feet) to ensure 100 percent containment. In general, the fence must be structurally sound, maintained in good repair, and of sufficient construction to contain the animals.



Selected Studies on Farmed Cervid Fencing



VerCauteren, et al. (2010) evaluated the ability of wild-caught white-tailed deer to jump progressively taller woven-wire fences. They documented a 100 percent deterrence rate when the test fence was 2.4 m tall, suggesting that a 2.4 m fence will contain or exclude most deer under similar conditions. However, a survey of 150 wildlife biologists found six individuals who had witnessed deer jump fences higher than 2.4 m, suggesting that only a higher fence could achieve 100 percent deterrence. Other factors that may reduce a fence’s effective height include topography, snow depth, and the motivation level of the cervid to penetrate the fence.



VerCauteren, et al. (2007a and b) also measured behaviors and contacts through game-farm fences between farmed and wild white-tailed deer in Michigan and between farmed elk and wild elk and mule deer in Colorado. All sites in Michigan employed a single 3 m high woven-wire fence. Fence types in Colorado included a single woven-wire fence (2.4 m high), double woven-wire fences separated by 1 to 4 m (2.4 m high), and a single woven-wire fence (2.4 m high) plus a 3-strand offset electric fence either inside or outside the woven-wire fence. The study recorded only two direct naso-oral contacts between wild and farmed deer in Michigan during more than 77,000 hours of camera monitoring. Conversely, 77 interactions were documented between wild and farmed elk involving naso-oral contact. No direct contacts were observed through double woven-wire fences. Risk of direct contact was about 3.5 times greater for single woven-wire fences compared to an offset electric fence attached to the single woven-wire fence.



Expanding on the offset electric fence type, Fischer, et al. (2011) examined the effectiveness of a baited electric fence, as an addition to an existing single woven- wire fence (2.4 m high), for reducing fenceline contact between captive elk. They reported 426 direct contacts between elk through the existing woven-wire fence during trials without the electric fence; 0 direct contacts occurred between adult elk or the woven-wire fence when the baited-electric fence was in place.



Literature Cited



Fischer, J.W., G.E. Phillips, D.M. Baasch, M.J. Lavelle, and K.C. VerCauteren, 2011. “Modifying elk (Cervus elaphus) behavior with electric fencing at established fencelines to reduce disease transmission potential.” Wildlife Society Bulletin 35:9-14.



VerCauteren, K.C., M.J. Lavelle, N.W. Seward, J.W. Fischer, and G.E. Phillips, 2007a. “Fenceline contact between wild and farmed cervids in Colorado: Potential for disease

transmission.” Journal of Wildlife Management 71:1594-1602.



VerCauteren, K.C., M.J. Lavelle, N.W. Seward, J.W. Fischer, and G.E. Phillips, 2007b. “Fenceline contact between wild and farmed white-tailed deer in Michigan: Potential for disease transmission.” Journal of Wildlife Management 71:1603-1606.



VerCauteren, K.C., T.R. Vandeelen, M.J. Lavelle, W. Hall, 2010. “Assessment of abilities of white-tailed deer to jump fences.” Journal of Wildlife Management 74:1378-1381.



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Appendix III. Sample Collection



When CWD is suspected in a live or dead animal, or when an animal dies and is over 12 months of age, the owner must immediately report to a State official and ensure samples are submitted for CWD testing in accordance with APHIS instructions. Animals less than 12 months of age may be submitted for CWD testing if required by the State official. State officials or APHIS employees may approve reporting schedules other than immediate notification when herd conditions or circumstances warrant it in the opinion of both the State and APHIS.



It is the responsibility of the herd owner to have samples collected and preserved properly or to preserve the head by refrigeration for sampling. Refrigerated heads may be shipped to an APHIS-approved CWD laboratory for this purpose. Prior notification and approval is required from the laboratory before shipping whole heads. Owners must ensure that fresh samples or heads can be refrigerated over weekends and holidays. A link to CWD approved labs is:

http://www.aphis.usda.gov/animal_health/lab_info_services/approved_labs.shtml



The obex and medial retropharyngeal lymph nodes (MRPLNs) must should be collected on all animals regardless of susceptible species. Scientific evidence shows that in although MRPLNs may be early indicators of CWD in deer and the obex may be an early indicator of CWD in elk, the sensitivity for early CWD detection is increased in both deer and elk when both obex and MRPLNs are tested. . The obex and MRPLNs should be fixed in 10 percent neutral buffered formalin. Animal identification (eartags, tattoos, etc.) may be should be submitted with a portion of the skin (hide) or ear attached, are best submitted as fresh or frozen tissue (not preserved), and must be kept linked to the diagnostic specimens if DNA testing is requested. . These samples can be used for DNA testing if there is some dispute regarding origin of the sample Chain of custody principles should be followed in the field and the laboratory to assure sample integrity.. The owner may observe the sampling and labeling procedures to assure his or her sample is properly identified.



A link to VS Form 10-4 can be found in in Appendix VII.



The collector will include the following with each diagnostic submission:

1. Completed VS Form 10-4 or an equivalent form with the same information found on the 10-4. (Note:

Complete VS Form 10-4 with the approval of the State official or accredited veterinarian who will in turn obtain the approval of the AVIC).

In the case of whole heads submitted to a laboratory by the owner, the owner’s name, address, phone number, herd ID, and the animal’s ID numbers, age or date of birth, breed, ***, and any clinical signs observed should be included with the shipment.

2. All ID devices, tattoos, and any brands on the animal.

3.2. Age of animal based on owner records.

4.3. Herd ID, species, breed, and *** of animal.

5.4. Obex/brainstem and MRPLN collected and packaged as described below.

6.5. Any additional samples as requested by the State Veterinarian or AVIC, including samples requested for research. (Any research will be done at no charge to the owner).



A. Safety Precautions



It is the responsibility of the collector to take appropriate safety precautions. Measures should be taken to avoid contact with specimens. To minimize exposure to pathogens, the following precautions should be taken:

1. Wear personal protective equipment (PPE) at all times. (See Section B below.)

2. Cover cuts, abrasions, and wounds with waterproof dressing if not covered by PPE.

3. Wear gloves while handling specimens and formalin. Optionally, Use face and respiratory protection, including a well-fitted respiratory mask and face shield or goggles to protect from infective droplets or tissue particles

4. Use 10 percent neutral buffered formalin in a well-ventilated area.

5. Take steps to avoid creating aerosols, splashes, and dusts.



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6. Wash hands and exposed skin following collection procedures.

7. Wash and disinfect protective clothing and instruments thoroughly after use. Use 50 ounces (6 1/4 cups) bleach to enough water (78 ounces or 9¾ cups) to make 1 gallon of disinfectant solution; this solution will remain effective at room temperature (at least 18.3 °C or 65 °F) for 1 hour.

8. If rabies is suspected, do not proceed with any tissue collection. Instead, contact the approved laboratory for instructions on submission of the entire head to the laboratory for rabies testing. After rabies testing is completed, the laboratory will proceed with CWD sampling on rabies-negative brains.



B. Personal Protective Equipment



Personal protective equipment (PPE) is designed to minimize exposure to pathogens while collecting samples.



According to the Occupational Safety and Health Administration, PPE is defined as “specialized clothing or equipment worn by employees for protection against health and safety hazards.� PPE is designed to protect many parts of the body (i.e., eyes, head, face, hands, feet, and ears.).



PPE is selected based on the environment, physical hazards, and ability to complete the task. PPE is a balance between protection and comfort. PPE should protect an individual from the physical hazards of the collection environment while allowing the individual to comfortably collect specimens. Even though the environment where collecting specimens will differ, the following PPE should be worn at all times during collection of CWD specimens:



1. Skin Protection

Protect your skin from contact with fluids during specimen collection. Wear waterproof coveralls, preferably disposable, or coveralls with a waterproof apron and forearm protectors.

2. Eye and Face Protection

Protect your eyes and face from any aerosols, splashes, or dusts that may be created while collecting specimens. Eye protection includes safety glasses, safety goggles, or a face shield.

3. Hand Protection Gloves

a. Wear metal or mesh gloves. Always wear the cut-resistant glove (Hantover, Koch, or Packer) on the hand that is not holding the knife. Find a cut-resistant glove that fits against your skin and then wear a rubber glove on top of it.

b. Wear latex or nitrile examination gloves or thick rubber gloves that extend halfway up the forearm. Many people prefer the long, thick rubber gloves for the added protection.

4. Foot Protection

Protect your feet from injuries such as spills or splashes, impact, compression, or exposure. Wear steel-toed rubber boots when collecting specimens. If steel-toed boots are not available, pullover rubber boots are acceptable.

5. Respiratory Protection

Face masks or respirators are recommended if the environment includes aerosols, splashing, or flying debris as may be encountered with certain methods of brain removal or tissue handling. CWD cannot be transmitted through the air or to humans. However, other zoonotic diseases such as rabies may be present during CWD collection. Also, Listeria monocytogenes and Arcanobacterium pyogenes are each known to cause brain abscesses in cervids; Listeria sp. should be considered a potential zoonotic agent.



Instructions for Veterinarians and Animal Health Technicians

1. Collector’s Responsibility

Specimens submitted to NVSL or the approved laboratories must be traceable to the source animal and farm. The sample collector should follow all instructions for sample collection, completing VS Form 10-4 or its equivalent and labeling sample containers. The sample collector must accurately complete the specimen collection and submission process. Failure to do so may result in the erroneous destruction of animals or loss of herd status, which is an irretrievable economic loss to herd owners.

When collecting specimens:

a. Properly collect brainstem with obex, and at least one both left and right MRPLN.

b. Correctly label specimen collection containers.



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c. Correctly package specimens to meet Federal transportation guidelines. For Category B (UN3373) packaging and shipping details, contact the receiving laboratory, or NVSL, or visit the following Web site: www.aphis.usda.gov/animal_health/lab_info_services/packaging_labeling.shtml

d. Properly complete the specimen submission form (VS Form 10-4 or electronic 10-4, or equivalent submission form). Be sure to indicate whether the animal was an exposed animal or an animal with no known exposure. Also indicate whether the animal was exhibiting clinical signs. If the animal exhibited clinical signs, list the signs in the Additional Data Section of the VS Form 10-4 or equivalent form.

e. Make four copies of the completed VS Form 10-4 or equivalent form:

One for your files (submitter’s copy).

One for the animal owner or collection site.

One for the VS Area Office.

One to be submitted with the specimen.

f. Follow the laboratory’s procedure for notifying the laboratory of incoming specimens.

g. Contact the delivery service. Ensure that the package containing any fresh tissues for CWD testing will be shipped with ice packs for overnight delivery to the laboratory.



2. Sample Quality

A list of laboratories approved to conduct CWD testing is available at: http://www.aphis.usda.gov/animal_health/lab_info_services/approved_labs.shtml

All samples should be collected and submitted to the lab irrespective of the state of autolysis. Approved labs should evaluate the condition of the autolyzed samples to determine if the samples are of sufficient quality to be reliably tested or if the samples should be sent directly to NVSL.



3. Labeling Sample Containers

The specimen collection containers must be properly labeled. The information on the label provides detailed information to the laboratory regarding the specimens. The sample number or sample bar code on the container must be the same as on the completed VS Form 10-4 (or equivalent form).



Clearly label both the top and the sides of the sample container. Identify the sample by typing the information, using a permanent marker, or affixing the bar code (if available). Verify that the sample number that appears on the top and side of the sample container and the completed VS Form 10-4 (or equivalent form) are identical.

The side label must include:

a. Date of collection.

b. Producer name.

c. Species.

d. Type of specimen.

e. Official animal ID number.

f. Sample ID number (number assigned to this sample on the VS Form 10-4 or equivalent form).



4. Samples and Sample Packaging

Properly preserve CWD specimens to ensure accurate test results. CWD diagnosis may require the submission of fresh and fixed specimens.



Fresh tissue specimens are used for Western blot and ELISA assays. Fresh tissue specimens must be kept chilled. While dry ice may be used, it is usually best to ship the chilled tissues overnight on ice packs.



Formalin-fixed specimens are used for IHC testing, histopathology and may be acceptable for DNA comparison (although fresh or frozen tissues are preferred for DNA testing).. The specimen must be submerged in 10 percent neutral buffered formalin (follow the guideline of 10 parts buffered formalin per 1 part specimen). Do not freeze the formalin-fixed specimens.



Use the following table as a guide for proper tissue specimen collection for routine testing, and for exposed animals, suspect animals, and animals with specific clinical signs suggestive of CWD. Animals with "specific clinical signs" include those that are non-ambulatory, ante-mortem condemned or die before



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slaughter, or are ataxic. Suspect animals are highly suspicious for CWD because they are exhibiting central nervous system (CNS) signs.



Suspect and presumptive-positive animals should be submitted on separate VS Form 10-4s and shipped promptly to allow NVSL to prioritize testing these cases. Note: If rabies testing is required, contact the laboratory for instructions on submitting the entire head. After rabies testing is completed, the laboratory will proceed with CWD sampling on rabies-negative brains from animals presenting with neurologic symptoms, and/or are unthrifty (debilitated), may be salivating, or exhibiting nonspecific respiratory signs.



Ensure the sample container correctly lists all specimens included.



Tissue specimens for CWD testing

10 percent neutral buffered formalin: Single container for each animal Fresh: Western blot and ELISA

Left and Right MRPLNs Left and Right MRPLNs



Obex with 1-2 cm brain stem (including the apex of the “V” in the obex)

Obex with 1-2 cm brain stem (including the apex of the “V” in obex)



Tonsils (optional)

Tonsils (optional)



Animal ID device(s) (optional). Collect all animal ID devices with a quarter-sized piece of tissue (ear, hide, etc.) attached to each device. This will allow DNA verification if necessary. This should be kept fresh, but some laboratories will accept ID tissue samples in formalin. Verify with the receiving laboratory.

Animal ID device(s) (optional). Collect all animal ID devices with a quarter-sized piece of tissue (ear, hide, etc.) attached to each device. This will allow DNA verification if necessary. This should be kept fresh, but some laboratories will accept ID tissue samples in formalin. Verify with the receiving laboratory.





5. Collection Procedures



The collection of the obex and MRPLNs can be completed using several methods. However, these collection procedures describe the preferred methods to prevent inadvertent damage to the tissues during collection. Other methods may be used. Contact an experienced professional for more information regarding alternative collection methods.



The link to the APHIS CWD website to find the CWD Program Sample Collection Guidance with dissection photos and instructions can be found in Appendix VII.



The following equipment will help ensure proper specimen collection:

a. Sharp boning knives.

b. Disposable scalpel blades, disposable scalpels, or a large scalpel blade is acceptable.

c. Brown-Adson or rat-tooth forceps.



d. Meat cutting bone saw, hacksaw, or electric saw when brain removal is required.

e. Disposable cutting surfaces such as cardboard, plastic or Styrofoam.

f. Small hand nippers can be used on the hyoid bones or you may cut through at the soft cartilage of the joint using a knife.

g. Sharp stainless steel scissors.

h. Brain stem/obex spoon, grapefruit knife, or other brain stem scoop.



6. Obex Collection Procedure (Via Foramen Magnum)

a. Incise the head of the animal at the atlanto-occipital joint (between skull and first vertebra). Cut behind the back of the ears and extend the cut around and through the front of the larynx. Sever the brain stem as far to the posterior as possible during the removal process.



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b. Position the head upside down (ventral side up). Locate the occipital condyles and foramen magnum (FM). Locate the brain stem inside the FM. Trim the dura mater around the brainstem and cut the attached cranial nerve trunks.

c. Gently lift the brain stem with forceps and insert the spoon into the dorsal aspect of the FM between the brainstem and dorsal calvarium.

d. Advance the spoon 2-3 inches rostrally until it contacts bone to sever the cerebellum.

e. Reposition the spoon in the ventral aspect of FM between the brainstem and the ventral calvarium. Advance the spoon until it contacts bone and transversely sever the brain stem.

f. Remove the brain stem using the spoon and forceps. Examine to ensure the proper obex sample (bifurcation or “V”) is preserved.

g. Further trim the brain stem section by making a transverse cut 3/4 inch in front of the “V” shape bifurcation and an equal distance behind the bifurcation for good fixation.

For IHC testing: Place the trimmed obex and brainstem pieces in a jar of 10 percent neutral buffered formalin (10:1 ratio of formalin to tissue sample).



7. Medial Retropharyngeal Lymph Node (MRPLN) Collection Procedures

The MRPLN’s are medial to the stylohyoid bones on the dorsolateral surface of the pharyngeal muscles and dorsal to the carotid artery.

a. With the head positioned upside down, locate the esophagus and trachea in relation to the FM.

b. Lift the trachea and dissect muscles forward of the FM (rostrally). Locate the left and right medial retropharyngeal lymph nodes (RPLN) halfway between each corner of the jaw bone and the FM, caudal to the nasopharynx, and deep to the salivary gland. Lymph node consistency is much firmer and rounder than the surrounding tissue.

c. Remove each left and right medial RPLN and longitudinally incise each LN to confirm lymphoid tissue.

For IHC testing: Place the medial RPLNs in the same formalin jar with the obex.



8. Head Removal and Whole Head Packaging Procedure That May be Used by Owners for Submission to Laboratory



It is best to first contact the approved laboratory for instructions on submission of whole heads for CWD testing. Some laboratories may not accept whole heads.



Tools

a. Sharp boning knife.

b. Two heavy duty plastic bags and ties.

c. If shipping the head, use shipping container with cooler, large heavy-duty plastic bag, absorbent material and four frozen cool packs. Contact your inspector or the VS Area Office for shipping containers. A list of Area Offices can be found at http://www.aphis.usda.gov/animal_health/area_offices/





Procedures

a. If the carcass is intact, remove the head. This is done at the atlanto-occipital joint, which is where the skull meets the first cervical vertebrae.

b. Position the animal in ventral recumbency (lying on its abdomen).

c. Remove the head at the hinge joint where the skull meets the first cervical vertebrae (just behind the ears) using the following steps:

To locate the “hinge” area where the skull meets the first cervical vertebrae, grasp the nose and move the head up and down to locate the joint.

Insert the knife into the neck between the first cervical vertebrae and the throat. Cut downward (ventrally) with blade directed away from you through the throat tissue and skin. (Cutting down through the skin readily dulls the blade.)

Cut down to the membrane that covers the spinal cord; cut through the membrane exposing the spinal cord. Then cut the spinal cord as far from the head (caudally) as possible so that it is kept as long as practical.

Cut the lateral ligaments connecting the skull to the vertebra in a ventral to dorsal direction on both sides. This is usually best accomplished with the tip of the knife directed between the skull and vertebra.



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Once the lateral ligaments have been severed, cut through the remaining tissue to remove the head from the carcass.





Maintain any animal identification attached to the ears (ear tags, etc) in place and double bag the head..Secure each bag in a manner that will prevent leakage by tying a knot in the bag or using twist ties, string, or cord.

Chill the head before placing in the cool box and refrigerate the head until and during shipment to the laboratory in the cool box.

d. To pack the cool box: Put cool packs in the bottom, insert large plastic bag, insert absorbent material, insert double bagged heads, and seal the outer plastic bag. Place cool packs on top of bag and close cooler top. Insert submission form between cooler top and exterior box. Ship overnight. Use at least four chill packs per box and an additional chill pack for each additional head if more than two heads are shipped in the same cool box.



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Appendix IV. Guidelines on Environmental Contamination and Recommended Procedures for Disinfection and Decontamination of Premises



When possible, with a signed herd plan,cleaning and disinfection should be conducted under the supervision of a State Veterinarian or APHIS representative Administrator as follows:

(1) Drylot areas. Remove the manure and top 1-2 inches of soil to reduce contamination. Bury, till under, or compost the removed material in areas not accessed by domestic animals or wildlife.

(2) Cement, wood, metal, and other non-earth surfaces, tools, equipment, instruments, feed, hay, bedding, and other materials. Remove all organic material and compost or incinerate. Clean and wash all surfaces, tools, equipment, and instruments using hot water and detergent. Allow all surfaces, tools, equipment, and instruments to dry completely. Disinfect items by incineration at high-temperature or autoclaving at 136 °C for 1 hour. To clean dry surfaces, apply a 2-percent chlorine bleach solution at room temperature at least 18.3 °C for 1 hour.





Chronic wasting disease (CWD) is an infectious disease of cervids. The agent is believed to be transmitted laterally. Current models show that environmental contamination may be important in transmitting and perpetuating the disease. Once a CWD-positive animal is identified on a premises, the premises should be quarantined until adequate decontamination has been performed. This is recommended to reduce the risk of CWD exposure and infection in new cervids are restocked on that site following completion of a herd plan.



These guidelines base the suggested preferred herd plan on depopulation of the entire herd following detection of the index positive animal. If a producer chooses long-term quarantine, additional restrictions on the herd may be required and will be specified in the herd plan. The State will give the plan to the owner of the premises for agreement. The basic guidelines below provide a framework for developing these herd plans.



None of the following cleaning and inactivation procedures guarantees elimination or inactivation of the infectious prion agent; however, the methods listed below are the most effective procedures to reduce prion levels and activity based on current information. These recommended procedures may be altered as new information becomes available.



If a producer does not follow the recommendations in the herd plan and CWD reoccurs in animals on the premises, the producer will not be compensated for the destruction of those animals and may be responsible for infecting other cervids.



Principles and Approach:

The primary methods of CWD transmission and the time from infection to shedding are not known. Therefore, it is assumed that animals may shed the CWD prion into the environment before the onset of clinical disease. Published scientific studies have reported that the CWD prion may be shed into the environment via saliva, urine, and feces. Prions resist breakdown in the environment (i.e. to exposure to sunlight, freezing, or desiccation) but may slowly break down with time.



Decontamination procedures will be directed at portions of the facility or items most likely to harbor the agent. Areas where animals (particularly CWD positive animals) have resided will be the most contaminated. These areas should be evaluated by:

1. Assessing the facility in detail to document areas of animal congregation or particular movement patterns.

2. Characterizing the entire facility in terms of concentration of animals over time. This includes identification of fence lines (past and present), pens, corrals or handling facilities, watering and feeding areas (including natural water sources), points of concentration in a landscape (i.e. sheltered areas, woodlots etc.), drainage areas, and calving areas.

3. Identifying where known positive or suspicious animals resided relative to the areas of animal concentration. In the case of clinical animals, identify those areas where they resided during the time they were clinical.



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4. Considering the physical nature of surfaces as well as topography and drainage of the area that might create concentration of the agent.



Categorization of Premises:

Premises will be categorized as premises with “No to Minimal Environmental Contamination” or “Moderate to Severe Environmental Contamination”. Where applicable, the State or Federal designated epidemiologist, with concurrence of the State or APHIS veterinarians, will assess the premises.



Factors Used in Decisionmaking:

1. Origin of the positive animals (born to the premises or introduced).

2. Herd history verified through records to give confidence in the herd CWD status (i.e., degree of certainty, or uncertainty, in relation to possible unreported cases).

3. The number of CWD cases (clinical and preclinical) originating from or occurring over time on a premises.



Basic Definitions for Categories

A. No to Minimal Environmental Contamination: A premises where there is little evidence that there has been transmission on the premises and there is no evidence of longstanding infection of the herd. The number of cases is minimal and history and records indicate that the animals likely contracted the disease on another premises (i.e., purchased or trace animals). The animals are preclinical at the time of CWD diagnosis or are early in the clinical course of the disease.



B. Moderate to Severe Environmental Contamination: Those premises where there is evidence that CWD has been identified inmultiple animals ; or those premises where a positive animal was exposed in another herd and dies of CWD or is euthanized late in the clinical course of the disease (i.e., animals are not removed from the herd while they are preclinical or early in the clinical course of the disease).



Recommended Procedures for Disinfection and Decontamination of Premises

In 2013, EPA amended the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to include “prion” in the definition of ‘pest’. This will allow for the EPA registration of any commercial products for the disinfection and decontamination of prions. This is yet to be determined.



Therefore, none of the following suggested disinfection and inactivation procedures will guarantee elimination or inactivation of the infectious agent. However, based on current information on the efficiency under laboratory conditions of the disinfection methods listed, it is likely that these procedures will reduce the amount of infectivity in the environment. Until more specific information becomes available, good sanitary practices are recommended for all cervid husbandry activities. The following methods below should be applied where infected or exposed animals have been housed or maintained.





A. No to Minimal Environmental Contamination Premises



Pastures

Intensive measures are not required.



Dry lot – Where CWD-positive animals have been held in close confinement:

Remove organic materials (manure, feed, bedding, and other organic material) and bury the removed material in areas not accessed by farmed or wild animals. Composting may be used to reduce the volume of organic materials. Composted material should be buried deeply, incinerated, or digested by alkaline hydrolysis after composting is complete. Composting alone does not inactive prions.



Earth Surfaces Inside Structures or Used for Confinement

Remove and dispose the organic material as described for ‘Dry lot;’ Bury the removed material in areas not accessed by farmed or wild cervids.



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Nonearth Surfaces

(These include cement, wood, metal, tools, equipment, instruments, and other artificial items)

Remove all organic material or items (such as wooden feed bunks) and incinerate by high temperature incineration methods if possible.

Clean and wash surfaces and other items using hot water and detergent.

Allow all surfaces, tools, and equipment to dry completely before disinfecting and sanitizing using the methods outlined in Section B below.





Restocking

The premises may be restocked with non-cervid species immediately after decontamination. The premises may be restocked with cervids 1 year after decontamination. If premises are restocked with cervids they should immediately enroll in the herd certification program and all mortalities must be reported, investigated, and CWD tested regardless of age. If the premises are located in a CWD-endemic area, or any area where CWD has been found in free-ranging cervids, restocking with cervids is not recommended. If restocking with cervids is done, then additional biosecurity practices to minimize CWD exposure should be considered



Fencing Requirements

Fences should be maintained to prevent ingress and egress of cervids for at least 5 years. Such events must be reported immediately to the State authority.



B. Moderate to Severe Environmental Contamination Premises



Pastures

Effective inactivation of the agent will destroy the forage and should only be considered where exclusion of animals from high-use areas is not an option. These will be approached on a case-by-case basis.

Small pastures where CWD-positive animals have resided or particular areas in a pasture where animals are known to have congregated may be treated as follows:.

1. If practical, till soil under or do not use area to graze susceptible animals.

2. If this is not practical, do not use the pasture until the animal waste has decomposed and the weather has had an opportunity to dilute any infectivity.

3. Organic material (hay, accumulations of manure, etc.) in areas of congregation should be buried. Congregation areas include animal shelters, feeding grounds, and water sources (if applicable).





Dry lot – Where CWD-positive or CWD-exposed animals have been held in close confinement (this includes but is not limited to corrals, pens, stalls, and alleyways or pathways):

Remove organic materials (manure, feed, bedding, and other organic material). This material may be buried deeply in areas not accessed by farmed or wild animals, incinerated, or chemically digested. Composting may be used to reduce the volume of organic materials. Composted material should be buried deeply, incinerated, or digested by alkaline hydrolysis after composting is complete. Composting alone does not inactive prions.

In addition, remove the top 1 to 2 inches of soil to reduce surface contamination.. The soil removed may be buried deeply or incinerated.



Earth Surfaces Inside Structures or Used for Confinement

Remove and dispose the organic material as described for ‘Dry Lot’. When practical, remove the top 1 to 2 inches of soil to reduce surface contamination. Bury the removed material in areas not accessed by farmed or wild cervids.



Nonearth Surfaces

(These include cement, wood, metal, tools, equipment, instruments, grain feeders, hay feeders, panels, chutes, and working facilities).

1. Remove all organic material and deeply bury the removed material in areas not accessed by farmed or wild cervids.



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2. Clean and wash surfaces of items using hot water and detergent. A high-pressure washer after initial manual removal of organic debris and cleaning surfaces is recommended for thorough cleaning of large equipment items. Allow all surfaces, tools, and equipment to dry completely before disinfecting and sanitizing using the following suggested methods:

a. Autoclave instruments, small tools, and other items at 136o C (277 o F) for 1 hour. This method is more effective when preceded by the treatment described in b or c, below.

b. To clean dry surfaces, apply a 2 percent-available chlorine solution (equivalent to about 20,000 ppm available chlorine at room temperature (at least 18.3 o C [65 oF]) for 1 hour. This can be achieved by mixing 50 ounces [6 1/4 cups] of household bleach with enough water (78 ounces. or 9¾ cups) to make 1 gallon of solution. Rinse to remove solution after 1 hour of contact time.

c. For environmental purposes, use this disinfection method when the preceding methods are not available: Expose dry surfaces by applying a 1-molar solution of sodium hydroxide (an approximately 4 percent solution [5 ounces sodium hydroxide dissolved in one gallon of water]) at room temperature (at least 18.3 oC [65 o F) for at least 1 hour. Rinse equipment to remove solution after 1 hour of contact time.



Precautions: Professional judgment should be exercised in the choice and use of disinfectants. All disinfectants are hazardous to humans, animals, and the environment. Label directions should be carefully read and followed. If corrosive disinfectants are used directly on metal items, the items must be thoroughly rinsed with fresh water to minimize damage.



Synonyms for sodium hydroxide (NaOH) are caustic soda, soda lye, and sodium hydrate. Sodium hydroxide is a white, brittle solid that dissolves readily in water to form a strong alkaline and caustic solution and is used as an alkalinizing agent. Sodium hydroxide is very caustic and in solution is extremely corrosive. For environmental reasons, only use this disinfection method when the preceding method is not available.



Disinfectants, especially in concentrated form, may irritate the skin, eyes, and respiratory systems. Protective equipment such as coveralls, rubber boots, rubber gloves, masks, or respirators as well as eye protection should be worn while mixing and applying some disinfectants. If areas of the body are exposed directly to a disinfectant, they should be washed thoroughly with water. Any employee should notify his or her supervisor if excessive human or animal exposure to disinfectants occurs or if there is an accidental release into the environment.



Restocking

The premises may be restocked with non-cervid species immediately 1 month after decontamination. The owner must report all mortalities of non-cervid species to the State authority, and the causes of death must be determined. Non-cervid animals exhibiting clinical signs of progressive debilitating disease with or without a neurologic component, and which also may not respond to medical treatment, should be sent for complete necropsy evaluation.

The premises may be restocked with cervids 5 years after decontamination. If premises are restocked with cervids they must immediately enroll in the certification program and all mortalities must be CWD tested regardless of age. If the premises are located in an endemic area, or any area where CWD has been found in free-ranging cervids, restocking with cervids is not recommended regardless of time frame.



Fencing Requirements

If possible, fFences should be maintained to prevent the ingress and egress of wild cervids for at least 5 years. Such events must be reported immediately to the State authority.



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Appendix V. Carcass Disposal of CWD Positive Animals or Animals of Unknown Status



Destruction or inactivation of PrPres is difficult and few treatments have been documented as completely successful. In addition, there are currently no quality assurance or quality control methods to ensure successful prion inactivation. For that reason, we have provided a list of processes reported to be ones that reduce the amount or activity of the infectious prion material.



The following is a list of acceptable options for disposal of animals infected with chronic wasting disease (CWD) and animals from CWD-positive or exposed herds euthanized as part of a diagnostic or depopulation effort.



Options:

1. Incineration of carcasses in an Environmental Protection Agency-approved conventional incinerator, air curtain incinerator, or cement kiln. After incineration, ashes should be buried in an active, licensed landfill at a depth that meets local and State regulations to prevent scavenging or contamination of groundwater. Incineration of animals onsite with a mobile incinerator is an option as it presents the least risk of spreading contaminated materials by moving animals. However, mobile incinerators require large amounts of fuel to maintain an even, high temperature appropriate for prions.

2. High-pressure alkaline hydrolysis of carcasses followed by burial of the treated material in an active, licensed landfill at a depth that meets local and State regulations.

3. Removal of high-risk materials such as heads (with brain), spinal cords, and lymphoid tissues (including entire gastrointestinal tract) for incineration or alkaline hydrolysis followed by burial of the treated high-risk materials as well as the remainder of the carcass in an active, licensed landfill at a depth that meets local and State regulations for animal carcass disposal. Please note that CWD prions may be found throughout the body including skeletal muscle; therefore, this approach is not the most effective for prion reduction.

4. Rendering of carcasses. If a rendering facility is used, it must be one that does not provide rendered material for use in animal feeds. Food and Drug Administration Center for Veterinary Medicine guidance on rendering can be found at: http://www.fda.gov/downloads/Animal...Enforcement/GuidanceforIndustry/UCM052506.pdf



Burial of carcasses in a licensed, active landfill and/or burial onsite at a depth that meets local and State regulations for animal carcass disposal are options for disposal of CWD infected carcasses but these methods do not provide any inactivation of prions. Furthermore, disposal by composting does not provide any inactivation of prions, and must meet State and local environmental regulations and restrictions.



With all of the recommended methods, carcasses must be carefully transported between the collection location and treatment or burial sites to prevent the spread of potentially contaminated and infectious materials. Precautions should be taken to prevent ashes, blood, tissues, or feces from leaking from transport vehicles.



APHIS recommends first testing individual animals for prion protein by IHC or other official test and delay disposal until test results are obtained. Subsequently, disposal options involving incineration, alkaline hydrolysis, or rendering with burial of the treated materials can be used for the positive animals, and simple carcass burial in a landfill or onsite may be used for the negative animals.



These options provided are based on the available science of CWD inactivation. Changes will be made as appropriate as new information on CWD becomes available.



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Appendix VI. CWD Epidemiology Investigation and Report Template



A. Outline of Information



Preliminary Information: The following format is used to generate a summary of pertinent premises information. This summary typically precedes each situation report and does not change unless new or additional information becomes available.

(1) Information about Owners:

(a) Owner name or names.

(b) Owner physical addresses (if different from facility address) including county.

(c) Other contact information (i.e. home phone, cell phone, or email address).

(d) Herd or farm manager names and contact information (if applicable).

(e) Facility or premises owners and contact information (if applicable).

(2) Information about the Index Case:

(a) Index animal: Species, age, gender, breed, color, all forms of identification, other information or descriptions if applicable.

(b) Clinical signs exhibited by index animal? If so, list signs, duration, and whether died or euthanized.

(c) Location of index animal when clinical signs first observed (mortality/slaughter surveillance, on-farm, first-point, or other)

(d) CWD test confirmed positive (date, screening laboratory, other necessary information)?

(3) Information about the Facility or Premises:

(a) Physical location of facility (i.e., street address, GPS coordinates).

(b) Type of facility (i.e. breeding, feeding, exhibition, hunt preserve, other).

(c) Other facilities associated with index facility or premises?

(d) When was facility established?

(e) General description of facility (i.e., total acreage, confinement or modified confinement, type and condition of fencing and enclosure, flooring, traffic in and out of facility, other necessary information).

(f) A map or schematic of the facility will help officials understand the situation.

(g) Biosecurity of facility? Risks? Implementation?

(h) Handling facilities available on premises?

(4) Information about other animals in the index facility or adjacent to the facility or premises:

(a) Number and type of animals housed at facility or premises (physical inventory with identification).

(b) Other susceptible animals or species located on facility.

(c) Any other animals or species on facility affected? Clinical signs observed?

(d) Number of other animals on facility affected?

(e) Transmission believed to have occurred on premises?

(f) Testing history and level of testing for disease of concern (required monitoring or surveillance, etc.)

(g) Proximity of other susceptible species in adjacent facilities or enclosures or susceptible wild species. Potential for exposure to affected animals at facility?

(h) Types of facilities adjacent to the index premises and related information (i.e., distance, number of animals, type of facility, nature of exposure).

(i) Facility quarantined? Conditions of quarantine? Level of biosecurity?

(5) Facility Management Information:

(a) Identification systems used at facility? Any official identification in use?

(b) Level of management regarding but not limited to recordkeeping and availability of herd records.

(c) Management practices such as vaccination programs, feed sources and storage, sources of herd additions, marketing practices, animal movements, level of biosecurity maintained, and other areas.



Follow-up Information to be Included in Situation Reports or Final Narrative:

(1) Records/Regulatory issues:

(a) Record review: Herd additions and dispositions in preceding years; confirm existing inventory.

(b) If State requires an annual inventory, are owner’s records consistent with State’s records?

(c) Date of last regulatory inspection and findings.

(d) Has the owner complied with applicable regulatory requirements?

(2) Animal Movements (i.e., traces):



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(a) Movements in and out of the facility without change in ownership and reasons for movements (such as exhibition, breeding, or seasonal grazing).

(b) Movements into facility

i. Purchase of herd additions or trades to acquire new additions.

(c) Movements out of facility

i. Sale or marketing of animals (slaughter, exhibition, etc.) and channels (such as auction market, private treaty, commercial feeding or slaughter, or hunting).

ii. Mortalities

(d) Identification of other facilities that animals may have moved to (trace forwards).

(e) Identification of source facilities, especially if linked to index cases (trace backs).

(f) Dates of movements (acquisitions, dispositions). Investigation should extend back at least 5 years for CWD.

(g) Disease status of other linked facilities? Quarantine status of linked facilities?

(3) Additional premises information that might affect disease control, depopulation, or cleaning and disinfection:

(a) Pen layouts, pen sizes, structures (types and construction), equipment (types and materials), enclosure materials, and cover vegetation.

(b) Accessibility of animal pens.

(c) Soil types, general terrain.

(d) Surface and groundwater proximity and vulnerability.

(e) Proximity to other residences, businesses, and other entities and nature of these entities.

(f) Presence of other nonsusceptible species (domestic or wild) or human traffic that could compromise biosecurity.

(g) Access by index animals to various areas (such as pens) in facility.

(h) Other activities that may contribute to the risk of disease introduction (such as taxidermy, offsite hunting, breeding loans, or other hobbies).

(4) Other facilities:

(a) If epidemiologically linked to index premises, are these other facilities under State quarantine?

(b) Linked premises’ regulatory compliance, testing history, monitoring, etc.

(c) Any animals on linked premises exhibiting clinical signs?



Herd Summary Information:

(1) If selected animals or entire herd is depopulated, what is the suspected disease prevalence in the herd?

(2) What is the distribution of disease in the herd (i.e., restricted to certain areas in the facility or certain classes of animals)?

(3) Cleaning and disinfection considerations related to suspected level and distribution of environmental contamination in the facility.



Summary of Various Reports:

Situation Reports:

Situation reports (sitreps) are generally reserved for incidents or situations related to identification of newly infected herds or changes in State status (i.e., newly documented CWD in captive herds or wildlife). Information accrues rapidly early in an incident. The corresponding need for information is critical; a situation report may be necessary daily or semiweekly.



Supplemental Epidemiological Reporting:

Additional epidemiological information may be requested if not provided in sitreps or other reports from the State. This information can be used for planning or additional risk assessment related to herd plan development and could include information such as:

Map or schematic of facility, pens, structures, etc.

Proximity to surface water or groundwater.

Availability of handling facilities.

Terrain/soil types/surrounding land use.

Identification used on susceptible species.

Testing history.



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Any other information including, but not limited to, the information specifically mentioned in pages 1-3 of this document.



Final Epidemiological Report Narrative:

The final epidemiological report should contain sufficient detail to convey the known epidemiology of the outbreak or incident to the intended audience. The final report should also comment on elements of the herd plan and how these elements correspond to epidemiological findings, or how the herd plan is substantiated by epidemiological findings.



B: Situation Report (Sitrep) Format and Content

Facility/Premises Information:

A sitrep is always preceded by an initial summary of the farm or facility information. Most of this information should not change substantially from one sitrep to the next; however any changes or corrections identified should be noted.

This section briefly provides relevant background information and history related to the facility and index animal and may include information such as:

Owner name, address, geographic information system/global positioning system (GIS/GPS) information, farm name, and other information (depending on level of disclosure).

Name of county or State where premises is located.

Primary species (susceptible species), index case information (species, breed, age, ***, etc.)

Disease identified, date of testing or confirmation, laboratory where testing occurred, and reason for testing.

Type of facility (such as breeding, hunt preserve, or other) and when established.

Type and condition of enclosure.

Number of susceptible animals remaining at index premises.

Proximity to other susceptible animals.



Current Status:

This section contains relevant information and findings that have developed since the previous sitrep. Information in this section includes:

New laboratory results of interest from the index herd.

Notable activities by producer.

Changes in quarantine status of farm or breaks in quarantines.

Completion of final depopulation plan or herd plan.

Activities being conducted such as appraisal, depopulation, or cleaning and disinfection.

Signature of herd plan, VS Form 1-23, and other necessary documents by owner and related agency authorities.

Additional issues not previously identified.



Epidemiological Investigation

This section should relate information such as:

Findings of record reviews.

Progress of traceouts.

Identification of new traces and how they are associated with index premises.

Identification of new risk factors (biosecurity risks).

Closed-out traces.



Planning:

This section should provide information related to planned or pending activities such as:

Contingency planning for newly identified risks.

Plans for additional surveillance (traceout herds).

Plans for wildlife surveillance.

Plans for depopulation, cleaning and disinfection, and other needed activities.



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Note: In addition to the information specifically mentioned above, preparers should maintain an archive of previous sitreps, and attach them to any current sitrep to serve as a historical reference to the reader if needed.



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Appendix VII. Links to Forms and Documents



Forms and documents for application to the Approved State CWD Herd Certification include:

• VS Form 11-2

• MOU Between State and APHIS for CWD HCP

• Guidance to States on Application

These documents can be found on the APHIS CWD website at:

http://www.aphis.usda.gov/animal_health/animal_diseases/cwd/apply.shtml



A list of Approved State CWD HCPs can be found at:

http://www.aphis.usda.gov/animal_he...s/list_approved_st_cwd_herd_cert_programs.pdf



VS Form 10-4 laboratory submission forms can be found at:

http://www.aphis.usda.gov/library/forms/pdf/VS_Form10_4.pdf



VS Form 10-4A laboratory submission forms can be found at:

http://www.aphis.usda.gov/library/forms/pdf/VS_Form10_4a.pdf



CWD Program – “CWD Sample Collection Guidance” can be found at:

http://www.aphis.usda.gov/animal_health/animal_diseases/cwd/diagnostics.shtml



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THANKS to: Laurie Seale for sending this information so I could post it for the industry.