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Last modified: Thursday, August 17, 2006
Chronic wasting disease in UtahChronic Wasting Disease (CWD) is a relatively rare transmissible disease that affects the nervous systems of afflicted deer and elk. Infected animals develop brain lesions, become emaciated, appear listless and have droopy ears, may salivate excessively and eventually die. There is no evidence that CWD naturally infects other big game species or domestic livestock. Additional information CWD test results
Notices – Carcass regulations and importation
Maps
– Tested sample distribution – CWD sampling units E-book Important links Where is it? Chronic Wasting Disease has been found in three different geographic areas within Utah (see CWD positive map — (PDF format)). The disease was first discovered in Utah in 2002 in a buck taken during the rifle hunt near Vernal. A second positive was discovered in Utah in early 2003, when a mule deer doe that died in an agricultural field near Moab, Utah, also tested positive. A third area of Utah was found with CWD in late 2003 when a mule deer doe taken in a depredation situation near Fountain Green tested positive. To date, 38 mule deer and no elk have tested positive for CWD in Utah. The highest prevalence rate (two percent in the buck population) in Utah is found on Wildlife Management Unit (WMU) 13, the La Sal Mountains, where 26 of the 38 cases were found. Prevalence rates are less than one percent in the other two areas of Utah, near Vernal (WMU 9) and Fountain Green (WMU 16). Surveys have also found CWD in free-ranging deer and/or elk in parts of Colorado, Wyoming, South Dakota, Nebraska, New Mexico, Wisconsin, New York, West Virginia, the Canadian provinces of Saskatchewan and Alberta, and most recently in Kansas and Illinois. It has also been found in captive deer and/or elk in ten states and two Canadian provinces. In the endemic areas of Wyoming, Colorado, and Nebraska, it is found in less than one percent of wild elk and in one percent to 15 percent of wild deer populations. In 2005, Colorado confirmed that a bull moose tested positive for CWD, making it the first time CWD has been found in a wild moose. There is considerable concern that CWD will spread into additional Utah deer and elk populations. The Utah Division of Wildlife Resources is conducting random sampling of deer and elk to check for the disease especially in areas where the disease has already been detected. The DWR is also considering additional measures to inhibit the spread of the disease. What causes it? Neither viruses nor bacteria cause CWD. Instead, infectious proteins called prions seem responsible. Prion-caused diseases are known as transmissible spongiform encephalopathies (TSE). Examples of these diseases are: Bovine Spongiform Encephalopathy (BSE) ("Mad Cow Disease"), Scrapie (in sheep and goats) and Creutzfeldt-Jakob Disease (CJD) (in humans). Prion-caused diseases and their methods of transmission are not well understood. Research indicates that it is unlikely that direct transmission of CWD from infected animals to humans occurs. In December of 1999, the World Health Organization stated, "There is currently no evidence that CWD in cervidae (deer and elk) is transmitted to humans." However, the similarities between CWD and Creutzfeldt-Jakob Disease are cause for concern, and appropriate precautions should be taken with harvested animals.  Avoid tissues where prions accumulate Precautions Hunters should not harvest animals that appear sick, nor should they eat meat from suspect animals. While there is little evidence that CWD affects humans, the DWR advises hunters to take these simple precautions when handling the carcass of any deer or elk:
What is the DWR doing about CWD? The Utah Division of Wildlife Resources (DWR) first began looking for Chronic Wasting Disease in 1998 under the guidance of the Centers for Disease Control (CDC). This effort was initiated in response to three young human individuals who had contracted Creutzfeldt-Jakob Disease (CJD). All three of the infected people had consumed wild game, and one of the individuals was from Utah and had hunted and consumed wildlife from the state. Over 700 samples were obtained over a two-year period from hunter-harvested and symptomatic deer and elk from areas where this individual had hunted, none of which tested positive. Targeted surveillance continued between 1998 and 2002, and no positives were found during this time period. In early 2002, a CWD-positive deer was discovered in western Colorado (not far from the Utah border) which caused the DWR to conduct a more aggressive search for the disease. Over 1,500 animals were tested as a result of these increased efforts. One positive case was documented in a mule deer buck taken in northeastern Utah (WMU 9) during the hunting season. The DWR established a five-mile radius around the location from where the positive deer was taken and conducted hot-spot culling, which resulted in an additional 84 mule deer being tested for CWD, none of which tested positive. A second positive was found in the southeastern portion of the state in early 2003, when a mule deer doe exhibiting clinical signs of illness died in an agricultural field on the west side of the La Sal Mountains (WMU 13).  Elk afflicted with chronic wasting disease Photo by Dr. Beth Williams The unexpected finding of CWD in Utah caused the DWR to again increase surveillance efforts with a more intensive management program in 2003. Samples were collected from mule deer in 17 of the 30 WMU's and a goal was set for 2,138 samples. All sample goals were met with the exception of those established for WMU 14, which fell 10 samples short. A total of 3,220 tissue samples were collected and nine positive mule deer were found, which brought the state to a total of 11 known CWD cases. All positives, with one exception, came from areas where CWD had been found the previous year. One new area was documented in central Utah when a mule deer doe taken in a depredation situation near Fountain Green (WMU 16) tested positive. A total of 549 samples were submitted from WMU 16 and no other positives were found in this unit (see 2003 results — (PDF format)). In 2004, a five- to 10-mile radius was established around the location of the positive in WMU 16 and 107 deer were removed through hot-spot culling efforts. None of these animals tested positive for CWD. In addition to these samples, another 500 samples were taken from hunter-harvested mule deer in this unit, none of which were positive for the disease. Overall in 2004, 15 of the 30 wildlife management units were sampled (see 2004 map) and target sample sizes were obtained on most units except for those established for elk and units located in the western half of the state. Through surveillance and management efforts in 2004, an additional seven positives were found on WMU 13 and the prevalence rate for this unit was determined to be near two percent in the buck population. No additional positives were located in either of the other two positive areas (WMU 9 or 16) and prevalence rates remain below one percent for these areas (see 2004 results — (PDF format)). Surveillance continued in 2005, and 15 of 30 wildlife management units were sampled. More than 2,100 deer and more than 300 elk were sampled, and eight mule deer tested positive for the disease. Two of the deer that tested positive were taken in central Utah near the Spencer Fork Wildlife Management Area, about 20 miles north of Fountain Green, confirming that CWD is present in the central part of the state. In addition to the two central Utah bucks, five deer taken in the La Sal Mountains tested positive for the disease, as well as a yearling buck from the south end of Flaming Gorge Reservoir. This was the first CWD-positive deer found in that specific area, but other CWD-positive deer have been found in previous years near Vernal, just 20 miles to the south (see 2005 results — (PDF format)). In 2006, 17 of 30 wildlife management units were sampled. More than 1,800 deer and more than 400 elk were sampled, and seven mule deer tested positive for the disease. Six deer taken in the La Sal Mountains tested positive for the disease, as well as one buck from Brush Creek in Uintah County (see 2006 results — (PDF format)). The 2007 CWD sampling season ends July 1, 2008. Currently, 14 of 30 wildlife management units have been sampled (2007 map not yet available). For 2007, nearly 1,300 deer and more than 300 elk have been sampled, and five mule deer tested positive for the disease. Two bucks taken in the La Sal Mountains tested positive, as well as two from an area 15 miles north of Fountain Green, and one from Sanpete County, south of Mt. Pleasant (see 2007 results — (PDF format)). To date, a total of 38 positives have been discovered in Utah. Twenty-six of the 38 deer came from the La Sal Mountains, six came from the Vernal area, one was taken near the south end of Flaming Gorge, one was killed near Fountain Green and four were taken 15 to 20 miles north of Fountain Green. (see CWD positives map, 2003–2006). Management and surveillance summary The goal of the DWR is to maintain a management program for CWD that provides the public with factual information, provides early detection, and prevents spread of the disease. The DWR has actively participated in CWD management by working to prevent infection, eliminate infection, and perform maintenance activities in areas where CWD has been found. The DWR's objective is to sample all WMU's with adequate deer populations that will allow the collection of statistically valid sample sizes to detect the presence of CWD at a one percent prevalence level with 95 percent confidence limits. The primary source of samples will come from mule deer because of the higher reported prevalence rate, which can be greater than 15 percent, versus one percent prevalence rate in elk. By 2006, the goal to sample all wildlife management units in the state with adequate deer populations to determine distribution of CWD in the state was met. Beginning in 2006, some units that have been tested in previous years will be resampled. Units where CWD already exists will continue to be sampled on an annual basis to monitor the prevalence and distribution of CWD. Targeted surveillance, or the removal of symptomatic animals, will continue on all WMU's throughout the state. Sampling methods The medial retropharyngeal lymph nodes of mule deer in all sample units, as well as elk from positive deer units, are collected. All samples are sent to the Utah State University Veterinary Diagnostic Laboratory (UVDL) in Logan, Utah, for analysis. UVDL has been approved by the National Veterinary Sciences Laboratory (NVSL) to test for chronic wasting disease. UVDL uses the IDEXX HerdChek CWD Antigen EIA (IDEXX Laboratories, Inc., Westbrook, ME) and the PRECESS 48 system, (Bio-Rad Laboratories, Inc., Life Science Group, Hercules, CA) as rapid tests. Any positives that are detected by the Bio-Rad or IDEXX systems are verified using the "gold standard" Immunohistochemistry (IHC) assay test. Carcass regulations The DWR has taken measures to prohibit the import of deer and elk carcasses from known infection areas. Only the following parts of wild deer and elk may be imported from designated infection areas from other states.
It is unlawful to import dead elk, mule deer, or white-tailed deer or their parts, except for the carcass parts listed above, from the following states, provinces, game management units, equivalent wildlife management units, or counties. Additional areas may be added as necessary.
Non-residents transporting harvested deer and elk carcasses through Utah may do so if they do not stay in Utah more than 24 hours, do not leave any part of the animal carcass in Utah, and do not have their deer or elk processed in Utah. How can hunters help? Immediately report all deer that appear sick or emaciated to a DWR office, biologist or officer. The DWR will attempt to locate the animal and remove a tissue sample from the head for testing.
Hunters harvesting animals from areas where testing is needed may be requested to cooperate by removing the cape from the deer or elk in the field or by taking the head to a Division office immediately after it is caped. The DWR can then remove a lymph node sample for testing. Can hunters have their deer/elk tested for CWD? The DWR has implemented an aggressive surveillance plan to target deer in specific units throughout the state. CWD infection in the endemic areas of Wyoming, Colorado and Nebraska are found in less than one percent of wild elk populations and one to 15 percent of wild deer populations. Therefore, testing strategies mainly target deer and not elk, although the DWR will test any deer or elk exhibiting clinical symptoms of CWD. Hunters who have harvested a deer in one of the CWD sampling units (2007 CWD sampling units map), or who harvest an elk in a CWD positive area, are requested to take their animal to the nearest regional office or wildlife check station to have a tissue sample removed for testing. To qualify for testing, the animal must be older than one year old, must not have been dead longer than three days, and the head of the animal must not have been frozen at any time. Hunters may view the results on the Internet after allowing four to six weeks for processing. Hunters who harvest an animal in a non-target sampling unit, but still wish to have their deer or elk tested for chronic wasting disease, may do so at a cost of $25 by providing the head to the Utah Veterinary Diagnostic Lab in Logan, Utah or the Utah Veterinary Diagnostic Lab in Nephi, Utah. In this case, the DWR will remove a sample from any harvested deer or elk, but the hunter is responsible for getting the sample to the lab and for paying the $25 testing fee. Deer and elk must be older than one year of age to be eligible for testing. Utah Veterinary Diagnostic Lab Utah Veterinary Diagnostic Lab Ongoing research in Utah A research project is currently being conducted on the La Sal mountains (WMU 13) where prevalence rates for CWD are the highest in Utah (two percent of the buck population). The study is examining the migration patterns and reproductive behavior of mule deer on the La Sal Mountains and how this behavior may be related to prevalence and spread of CWD. The study, which began in early 2005, will take at least three years to complete and hunters are asked not to harvest mule deer with radio collars. If a deer is harvested that has a radio collar, hunters are asked to turn in the collar at nearest DWR office or game checking station. |
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