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The article offers information on chronic wasting disease (CWD), a naturally occurring prion disease in North American dear, Rocky mountain elk and moose. It notes that this disease was first confirmed in 2001 in Republic of Korea. Ferrets, several species of voles, white-footed mice, dear mice, and Syrian golden hamsters are among the experimental host range of CWD.

Abstract: The aim of the present study was to investigate the presence of Bartonella infections in elk populations. We report the isolation of four Bartonella strains from 55 elk blood samples. Sequencing analysis demonstrated that all four strains belong to Bartonella capreoli, a bacterium that was originally described in the wild roe deer of Europe. Our finding first time demonstrated that B. capreoli has a wide geographic range, and that elk may be another host for this bacterium. Further investigations are needed to determine the impact of this bacterium on wildlife. [Copyright &y& Elsevier]

The article presents an analysis of various factors influencing the attachment of prion protein to soil constituents. It discusses the potential implications of prions as agents of transmissible spongiform encephalopathies (TSEs), that is a form of neurodegenerative disease and explains the structure of pathogenic prion protein. It informs that environmental routes of TSE transmission are shown in TSE if deer, mouse and elk and stresses on the need of assessing the persistence, mobility and bioavailability of prions in soil for the management of TSE-contaminated soils.

Abstract: Elk in the Greater Yellowstone Area are a major reservoir for brucellosis, which represents an obstacle to eradication of the disease in domestic livestock. Furthermore, immune responses to Brucella abortus infection in the wild host are not well-understood. In this regard, in vivo-induced antigen technology (IVIAT) was employed to identify novel B. abortus antigens expressed during infection in elk. Sera collected from sero-positive Wyoming elk were pooled and absorbed against in vitro-grown cultures of B. abortus. Approximately 35,000 E. coli clones, expressing B. abortus DNA, were then screened by colony immunoblot, yielding ten genes with immuno-reactive products, to include seven proteins secreted beyond the inner membrane. Three products, an outer membrane protein (D15), malate dehydrogenase (Mdh), and an ion transporter (AfuA), were examined by Western blot against individual elk serum samples. Sero-reactivity was significantly more frequent for both Mdh and D15 in naturally infected animals, compared to vaccinated and uninfected elk, indicating that antibody to these two antigens is a predictor of natural infection. Cross-reactivity of all three proteins was next examined with serum samples from confirmed brucellosis-positive cattle. While variable patterns of reactivity were seen with the antigens, the sample group was equivalently reactive to AfuA and Mdh, compared to elk, suggesting that these antigens are commonly expressed during infection in both hosts. We conclude that the application of IVIAT to B. abortus may not only facilitate the identification of serologic markers for brucellosis in elk, but may provide further insight into biological processes of the pathogen in different hosts. [Copyright &y& Elsevier]

The article discusses the experimental transmission of chronic wasting disease (CWD) in red deer. The animals were euthanized and tested using 3 conventional immunological assays as well as mild to moderate neurological signs, weight loss and post-inoculation at 18-20 months were investigated. It indicates that tissues used for CWD diagnosis show strong abnormal prion (PrPCWD) accumulation, and determines that red deer are susceptible to oral challenge.

The spread of Chronic Wasting Disease (CWD) in the deer and elk population has caused serious public health concerns due to its potential to infect farm animals and humans. Like other prion disorders such a sporadic Creutzfeldt- Jakob-disease of humans and Mad Cow Disease of cattle, CWD is caused by PrP-scrapie (PrPSc), a β-sheet rich isoform of a normal cell surface glycoprotein, the prion protein (PrPC). Since PrPSc is sufficient to cause infection and neurotoxicity if ingested by a susceptible host, it is important to understand the mechanism by which it crosses the stringent epithelial cell barrier of the small intestine. Possible mechanisms include co-transport with ferritin in ingested food and uptake by dendritic cells. Since ferritin is ubiquitously expressed and shares considerable homology among species, co-transport of PrPSc with ferritin can result in cross-species spread with deleterious consequences. We have used a combination of in vitro and in vivo models of intestinal epithelial cell barrier to understand the role of ferritin in mediating PrPSc uptake and transport. In this report, we demonstrate that PrPSc and ferritin from CWD affected deer and elk brains and scrapie from sheep resist degradation by digestive enzymes, and are transcytosed across a tight monolayer of human epithelial cells with significant efficiency. Likewise, ferritin from hamster brains is taken up by mouse intestinal epithelial cells in vivo, indicating that uptake of ferritin is not limited by species differences as described for prions. More importantly, the iron content of ferritin determines its efficiency of uptake and transport by Caco-2 cells and mouse models, providing insight into the mechanism(s) of ferritin and PrPSc uptake by intestinal epithelial cells. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) was found in wild deer populations in the province of Alberta, Canada, in 2005, and there is concern that this finding could create significant costs related to the farmed elk and deer industry. These potential costs or “values at risk” can be used to assess the economic returns from CWD containment and eradication programs. Cost estimates of CWD to cervid farms range from $12 million for additional farm fencing to hundreds of millions of dollars in payments by governments to discontinue cervid farming. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is increasingly prevalent in multiple wild mule (Odocoileus hemionus) and white-tailed deer (O. virginianus) herds in North America. CWD was first found in Canadian wild mule deer in Saskatchewan in 2000 and has since spread into the neighboring province of Alberta. The infectious agent for CWD is a misfolded prion protein encoded by the PRNP gene. Previous studies revealed association between PRNP genotype and susceptibility to CWD in both mule and white-tailed deer in other regions. To investigate this link in Canadian populations, PRNP gene sequence was examined in 166 CWD- and 83 CWD+ mule deer, and 197 CWD- and 30 CWD+ white-tailed deer from Saskatchewan and Alberta. Two variable sites were found in mule deer, and 15 in white-tailed deer. In both species PRNP genotype was associated with CWD status. Mule deer possessing at least one copy of the common allele at codon 20 were less likely to test positive for CWD than expected, given the frequency of this allele in the population. A variant at codon 96 in white-tailed deer was also linked with reduced incidence of CWD. A greater knowledge of the genetic sources of heterogeneity in CWD susceptibility may improve our understanding of the mechanisms underlying the CWD epidemic in western Canada. [ABSTRACT FROM AUTHOR]

Summary: Chronic wasting disease (CWD), a prion disease of North American deer, elk and moose, affects both free-ranging and captive cervids. The potential host range for CWD remains uncertain. The susceptibility of the ferret to CWD was examined experimentally by administering infectious brain material by the intracerebral (IC) or oral (PO) route. Between 15 and 20 months after IC inoculation, ferrets developed neurological signs consistent with prion disease, including polyphagia, somnolence, piloerection, lordosis and ataxia. Upon first sub-passage of ferret-adapted CWD, the incubation period decreased to 5 months. Spongiform change in the neuropil was most marked in the basal ganglia, thalamus, midbrain and pons. The deposition of PrPCWD was granular and was occasionally closely associated with, or localized within, neurons. There were no plaque-like or perivascular PrP aggregates as seen in CWD-infected cervids. In western blots, the PrPCWD glycoform profile resembled that of CWD in deer, typified by a dominant diglycosylated glycoform. CWD disease in ferrets followed IC but not PO inoculation, even after 31 months of observation. These findings indicate that CWD-infected ferrets share microscopical and biochemical features of CWD in cervids, but appear to be relatively resistant to oral infection by primary CWD inoculum of deer origin. [Copyright &y& Elsevier]

The bovine spongiform encephalopathy (BSE) agent has been transmitted to humans, leading to variant Creutzfeldt-Jakob disease. Sheep and goats can be experimentally infected by BSE and have been potentially exposed to natural BSE; however, whether BSE can be transmitted to small ruminants is not known. Based on the particular biochemical properties of the abnormal prion protein (PrPsc) associated with BSE, and particularly the increased degradation induced by proteinase K in the N terminal part of PrPsc, we have developed a rapid ELISA designed to distinguish BSE from other scrapie strains. This assay clearly discriminates experimental ovine BSE from other scrapie strains and was used to screen 260 transmissible spongiform encephalopathy (TSE)--infected small ruminant samples identified by the French active surveillance network (2002/2003). In this context, this test has helped to identify the first case of natural BSE in a goat and can be used to classify TSE isolates based on the proteinase K sensitivity of PrPsc. [ABSTRACT FROM AUTHOR]

Abstract: Until recently, chronic wasting disease of cervids, the only prion disease affecting wildlife, was believed to be geographically concentrated to Colorado and Wyoming within the United States. However, increased surveillance has unveiled several additional pockets of CWD-infected deer and elk in 12 additional states and 2 Canadian provinces. Deer and elk with CWD have extensive aggregates of PrPSc not only in the central nervous system, but also in peripheral lymphoid tissues, skeletal muscle, and other organs, perhaps influencing prion shedding. Indeed, CWD is transmitted efficiently among animals by horizontal routes, although the mechanism of spread is unknown. Genetic polymorphisms in the Prnp gene may affect CWD susceptibility, particularly at codon 225 (S/F) in deer and codon 132 (M/L) in elk. Since CWD infects free-ranging animals and is efficiently spread, disease management will be a challenge. [Copyright &y& Elsevier]

Chronic wasting disease (CWD) of deer and elk is a widespread health concern because its potential for crossspecies transmission is undetermined. CWD prevalence in wild elk is much lower than its prevalence in wild deer, and whether CWD-infected deer and elk differ in ability to infect other species is unknown. Because lymphoid tissues are important in the pathogenesis of some transmissible spongiform encephalopathies such as sheep scrapie, we investigated whether CWD-affected elk and deer differ in distribution or quantity of disease-associated prion protein (PrPres) in lymphoid tissues. Immunoblot quantification of PrPres from tonsil and retropharyngeal lymph nodes showed much higher levels of PrPres in deer than in elk. This difference correlated with the natural prevalence of CWD in these species and suggested that CWD-infected deer may be more likely than elk to transmit the disease to other cervids and have a greater potential to transmit CWD to noncervids. [ABSTRACT FROM AUTHOR]

Transmissible spongiform encephalopathies are fatal neurodegenerative diseases that are caused by unconventional pathogens and affect the central nervous system of animals and humans. Several different forms of these diseases result from natural infection (i.e. exposure to transmissible spongiform encephalopathy agents or prions, present in the natural environment of the respective host). This holds true also for scrapie in sheep, bovine spongiform encephalopathy in cattle, chronic wasting disease in elk and deer, or variant Creutzfeldt–Jakob disease in humans, all of which are assumed to originate predominantly from peroral prion infection. This article intends to provide an overview of the current state of knowledge on the spread of scrapie, chronic wasting disease, bovine spongiform encephalopathy and variant Creutzfeldt–Jakob disease agents through the body in naturally affected hosts, and in model animals experimentally challenged via the alimentary tract. Special attention is given to the tissue components and spreading pathways involved in the key stages of prion routing through the body, such as intestinal uptake, neuroinvasion of nerves and the central nervous system, and centrifugal spread from the brain and spinal cord to peripheral sites (e.g. sensory ganglia or muscles). The elucidation of the pathways and mechanisms by which prions invade a host and spread through the organism can contribute to efficient infection control strategies and the improvement of transmissible spongiform encephalopathy diagnostics. It may also help to identify prophylactic or therapeutic approaches that would impede naturally acquired transmissible spongiform encephalopathy infections. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD), a transmissible prion disease that affects elk and deer, poses new challenges to animal and human health. Although the transmission of CWD to humans has not been proven, it remains a possibility. If this were to occur, it is important to know whether the ‘acquired’ human prion disease would show a phenotype including the scrapie prion protein (PrPSc) features that differ from those associated with human sporadic prion disease. In this study, we have compared the pathological profiles and PrPSc characteristics in brains of CWD-affected elk and deer with those in subjects with sporadic Creutzfeldt-Jakob disease (CJD), as well as CJD-affected subjects who might have been exposed to CWD, using histopathology, immunohistochemistry, immunoblotting, conformation stability assay, and N-terminal protein sequencing. Spongiform changes and intense PrPSc staining were present in several brain regions of CWD-affected animals. Immunoblotting revealed three proteinase K (PK)-resistant bands in CWD, representing different glycoforms of PrPSc. The unglycosylated PK-resistant PrPSc of CWD migrated at 21 kDa with an electrophoretic mobility similar to that of type 1 human PrPSc present in sporadic CJD affecting subjects homozygous for methionine at codon 129 (sCJDMM1). N-terminal sequencing showed that the PK cleavage site of PrPSc in CWD occurred at residues 82 and 78, similar to that of PrPSc in sCJDMM1. Conformation stability assay also showed no significant difference between elk CWD PrPSc and the PrPSc species associated with sCJDMM1. However, there was a major difference in glycoform ratio of PrPSc between CWD and sCJDMM1 affecting both subjects potentially exposed to CWD and non-exposed subjects. Moreover, PrPSc of CWD exhibited a distinct constellation of glycoforms distinguishable from that of sCJDMM1 in two-dimensional immunoblots. These findings underline the importance of detailed PrPSc characterization in trying to detect novel forms of acquired prion disease. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is an emerging transmissible spongiform encephalopathy (prion disease) of North American cervids, i.e., mule deer, white-tailed deer, and elk (wapiti). To facilitate in vitro studies of CWD, we have developed a transformed deer cell line that is persistently infected with CWD. Primary cultures derived from uninfected mule deer brain tissue were transformed by transfection with a plasmid containing the simian virus 40 genome. A transformed cell line (MDB) was exposed to microsomes prepared from the brainstem of a CWD-affected mule deer. CWD-associated, protease-resistant prion protein (PrPCWD) was used as an indicator of CWD infection. Although no PrPCWD was detected in any of these cultures after two passes, dilution cloning of cells yielded one PrpCWD-positive clone out of 51. This clone, designated MDBCWD, has maintained stable PrPCWD production through 32 serial passes thus far. A second round of dilution cloning yielded 20 PrPCWD-positive subclones out of 30, one of which was designated MDBCWD2. The MDBCWD2 cell line was positive for fibronectin and negative for microtubule-associated protein 2 (a neuronal marker) and glial fibrillary acidic protein (an activated astrocyte marker), consistent with derivation from brain fibroblasts (e.g., meningeal fibroblasts). Two inhibitors of rodent scrapie protease-resistant PrP accumulation, pentosan polysulfate and a porphyrin compound, indium (III) meso-tetra(4-sulfonatophenyl)porphine chloride, potently blocked PrPCWD accumulation in MDBCWD cells. This demonstrates the utility of these cells in a rapid in vitro screening assay for PrPCWD inhibitors and suggests that these compounds have potential to be active against CWD in vivo. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD), a prion disease affecting free-ranging and captive cervids (deer and elk), is widespread in the United States and parts of Canada. The large cervid population, the popularity of venison consumption, and the apparent spread of the CWD epidemic are likely resulting in increased human exposure to CWD in the United States. Whether CWD is transmissible to humans, as has been shown for bovine spongiform encephalopathy (the prion disease of cattle), is unknown. We generated transgenic mice expressing the elk or human prion protein (PrP) in a PrP-null background. After intracerebral inoculation with elk CWD prion, two lines of "humanized" transgenic mice that are susceptible to human prions failed to develop the hallmarks of prion diseases after >657 and >756 d, respectively, whereas the "cervidized" transgenic mice became infected after 118-142 d. These data indicate that there is a substantial species barrier for transmission of elk CWD to humans. [ABSTRACT FROM AUTHOR]

Sections of medulla oblongata, taken at the level of the obex, palatine tonsil and medial retropharyngeal lymph node from 10,269 captive Rocky Mountain elk (Cervus elaphus nelsoni), were examined by immunohistochemical staining with monoclonal antibody for the prion protein associated with the transmissible spongiform encephalopathy of cervids, chronic wasting disease (PrPCWD). The protein was detected in 226 of them. On the basis of the anatomical location of the deposits in the brainstem of 183 elk, four distinct patterns of distribution of PrPCWD within the parasympathetic region of the dorsal motor nucleus of the vagus nerve and the adjacent nuclei were observed. Mild gross lesions of chronic wasting disease (serous atrophy of fat) were observed in only three elk, all with spongiform degeneration; the other elk were considered to be in the preclinical stage of the disease. In contrast with the relatively predictable distribution of prion protein (PrP) in the brain and cranial nodes of sheep and mule deer, the distribution of PrPCWD in the brain and nodes of the elk was more variable and unrelated to their PrP genotype. One hundred and fifty-five of the 226 positive elk had deposits of PrPCWD in the brainstem and lymphoid tissues, 43 had deposits only in the lymphoid tissue and 28 had deposits only in the brainstem. [ABSTRACT FROM AUTHOR]

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Chronic wasting disease (CWD), a fatal transmissible spongiform encephalopathy of deer (Odocoileus spp.) and elk (Cervus elaphus), presents a challenge to wildlife managers because little is known about its transmission, yet it could severely threaten wildlife populations if action is not taken rapidly. Published mathematical models predict that CWD could devastate populations of free-living deer and elk, prompting wildlife managers to attempt large-scale eradication of deer in hopes of containing CWD outbreaks. Our objective is to critically examine the theoretical and empirical support for current models of CWD epizootiology, in light of herd health-management actions. We identify a critical, untested premise (i.e., strictly frequency-dependent transmission) that underlies the dire model predictions. We re-evaluate published comparisons of model output with field data and find little support for published model structures. Given the uncertainty surrounding the future effects of chronic wasting disease on deer and elk populations, and the potential costs of unnecessarily culling large numbers of charismatic and valuable animals, we propose that consideration of alternative models and management actions in a decision-theoretic framework is necessary for wildlife management actions to retain their scientific basis. [ABSTRACT FROM AUTHOR]

Clusterin (apolipoprotein J), a multifunctional protein involved in amyloidogenesis in Alzheimer's disease, was studied immunohistochemically in both human transmissible spongiform encephalopathies (TSEs) and a mouse model of human TSE. Clusterin immunoreactivity was co-localized with plaque-type deposits but not with punctate-type prion protein (PrP) deposits in human TSEs. On the other hand, clusterin-positive astrocytes were readily demonstrated in the regions of punctate PrP deposits, but not around plaque PrP deposits despite the presence of surrounding astrocytes. Clusterin expression in astrocytes was not disease specific, but the punctate immunoreactivity for clusterin was more prominently demonstrated in TSEs with punctate PrP deposits. Serial analysis in the mouse model of human TSE revealed that clusterin expression in astrocytes was enhanced in the lesions with punctate-type PrP deposits during the disease progression. Thus, the induction of clusterin expression in astrocytes could be more enhanced by punctate-type PrP deposits than by plaque-type deposits. The clusterin molecules co-localized in plaque PrP deposits might be derived not from surrounding astrocytes but from other resources such as cerebrospinal fluid and blood plasma, both of which contain clusterin in significant amounts. Taken together with previously reported findings of the anti-amyloidogenic property in clusterin, our findings suggest that clusterin may be induced as one of the important molecules participating in the neurodegeneration caused by abnormally deposited PrP. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) in captive and free-ranging cervids in the USA; its origin is obscure. Archival formalin-fixed and paraffin-embedded specimens of 16 captive mule deer brains with CWD were analyzed using immunocytochemistry for the disease-associated prion protein (PrP). The most prominent pattern of PrP deposition were plaque-like structures, a substantial proportion of which were florid plaques surrounded by a rim of spongiform vacuoles. The percentage of florid plaques was highly variable according to region, ranging from 0% to 52.7%. The highest percentage was observed in the medulla and basal ganglia, the lowest in the cerebral cortex. Only three brains contained no florid plaques. There were also punctate synaptic-type and perivascular deposits, particularly in areas of severe spongiform change, and subpial and subependymal plaque-like deposits, whereas cerebellar involvement was mild. Thus, CWD brain pathology prominently features florid PrP plaques, as does variant Creutzfeldt-Jakob disease (vCJD), but differs in other characteristics from vCJD. [ABSTRACT FROM AUTHOR]

Classical and modern studies of the pathogenesis of transmissible spongiform encephalopathy are reviewed, with particular attention paid to recent investigations of the routes of neuroinvasion. In various experimental models, a heirarchy of paths to the brain includes direct neural transit from the site of infection, replication in the spleen and neural entry through the spinal cord, and hematogenous spread. Possible modes and sites of therapeutic intervention are suggested. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is an emerging prion disease of deer and elk. The risk of CWD transmission to humans following exposure to CWD-infected tissues is unknown. To assess the susceptibility of nonhuman primates to CWD, two squirrel monkeys were inoculated with brain tissue from a CWD-infected mule deer. The CWD-inoculated squirrel monkeys developed a progressive neurodegenerative disease and were euthanized at 31 and 34 months postinfection. Brain tissue from the CWD-infected squirrel monkeys contained the abnormal isoform of the prion protein, PrP-res, and displayed spongiform degeneration. This is the first reported transmission of CWD to primates. [ABSTRACT FROM AUTHOR]

The article offers perspective on research reported by Angers et al. elsewhere in the issue on infections involving prions, their diversification and spread, and the contagious chronic wasting disease (CWD) found in wild deer and elk that is attributed to prions. The role of prions in bovine spongiform encephalopathy (BSE) and other diseases is noted. Genetic aspects of prion propagation are illustrated and discussed with reference to the biochemistry of polymers of misfolded prion protein called PrPs.

Reports on the effort of the United States Department of Agriculture's Animal and Plant Health Inspection Service to gain approval from the Office of Management and Budget to launch a national chronic wasting disease study and chronic wasting disease (CWD) herd certification program. Aim of supporting the captive deer and elk industry and reducing CWD in captive herds; Voluntary participation in the study and program if approved.

Focuses on hunter perceptions and behaviors related to chronic wasting disease (CWD) in Northern Illinois. Overview of CWD; Influence of CW on hunting participation of hunters; Sources of information on CWD.

Reports on the concerns about widening human exposure to variant Creutzfeldt-Jacob disease (vCJD) in elk and deer in the U.S. Formation of a committee at the Institute of Medicine to look into the matter; Fear of transfer of chronic wasting disease from animals to humans; Suggestions of the U.S. Centers for Disease Control and Prevention on the issue; Method of killing vCJD strains on surgical tools.

The article reports on the absence of cattle herds infected with brucellosis in U.S. as revealed by the Department of Agriculture. It mentions that the entire U.S. was declared as class-free for brucellosis since February to May 2008 due to the cooperation between states and the implementation of the brucellosis program. However, the disease may still occur due to the continued contact of livestock with the brucellosis-positive wildlife like the bison and elk from the Yellow National Park.

The article reports that researchers have completed their third year of evaluating and validating the first live rectal-tissue biopsy method for detecting chronic wasting disease (CWD) in captive and wild elk in Colorado. More than 1,500 biopsy specimens have been collected from captive elk in Colorado. 15 of the specimens were tested positive for CWD.

Chronic wasting disease (CWD), a prion disease of deer and elk, is highly prevalent in some regions of North America. The establishment of mouse-adapted CWD prions has proven difficult due to the strong species barrier between mice and deer. Here we report the efficient transmission of CWD to transgenic mice overexpressing murine PrP. All mice developed disease 500 ± 62 days after intracerebral CWD challenge. The incubation period decreased to 228 ± 103 days on secondary passage and to 162 ± 6 days on tertiary passage. Mice developed very large, radially structured cerebral amyloid plaques similar to those of CWD-infected deer and elk. PrPSc was detected in spleen, indicating that murine CWD was lymphotropic. PrPSc glycoform profiles maintained a predominantly diglycosylated PrP pattern, as seen with CWD in deer and elk, across all passages. Therefore, all pathological, biochemical, and histological strain characteristics of CWD appear to persist upon repetitive serial passage through mice. These findings indicate that the salient strain-specific properties of CWD are encoded by agent-intrinsic components rather than by host factors. [ABSTRACT FROM AUTHOR]

The article presents findings of a study on the transmission of chronic wasting disease through blood and saliva of deer, conducted by researchers at the Colorado State university and published in the October 6, 2006 edition of "Science." The study speculates on whether the disease can be spread by blood-sucking insects or social contact between animals. The methodology used in the study is described.

Chronic wasting disease (CWD) is a fatal prion disease in deer and elk. Unique among the prion diseases, it is transmitted among captive and free-ranging animals. To facilitate studies of the biology of CWD prions, we generated five lines of transgenic (Tg) mice expressing prion protein (PrP) from Rocky Mountain elk (Cervus elaphus nelsoni), denoted Tg(ElkPrP), and two lines of Tg mice expressing PrP common to white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus), denoted Tg(DePrP). None of the Tg(ElkPrP) or Tg(DePrP) mice exhibited spontaneous neurologic dysfunction at more than 600 days of age. Brain samples from CWD-positive elk, white-tailed deer, and mule deer produced disease in Tg(ElkPrP) mice between 180 and 200 days after inoculation and in Tg(DePrP) mice between 300 and 400 days. One of eight cervid brain inocula transmitted disease to Tg(MoPrP)4053 mice overexpressing wild-type mouse PrP-A in 540 days. Neuropathologic analysis revealed abundant PrP amyloid plaques in the brains of ill mice. Brain homogenates from symptomatic Tg(ElkPrP) mice produced disease in 120 to 190 days in Tg(ElkPrP) mice. In contrast to the Tg(ElkPrP) and Tg(DePrP) mice, Tg mice overexpressing human, bovine, or ovine PrP did not develop prion disease after inoculation with CWD prions from among nine different isolates after <500 days. These findings suggest that CWD prions from elk, mule deer, and white-tailed deer can be readily transmitted among these three cervid species. [ABSTRACT FROM AUTHOR]

The article presents information on the web site wildlifedisease.nbii.gov, from the U.S. Geological Survey's National Wildlife Health Center. A threat is stalking North America's deer and elk--chronic wasting disease. Triggered by the infectious proteins called prions, the brain-devastating ailment has attacked wild and captive animals in 14 U.S. states and Canadian provinces since the late 1960s.

Reports on a study which provides the evidence that chronic wasting disease can be transmitted through environments contaminated by carcasses or excrement of infected animals, in addition to spreading through direct interactions between animals. Need to consider potential exposure routes when attempting to control this disease; History of the identification of the disease; Significance of the findings for veterinary medicine.