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Articles 1 - 10 of 10
Full-Text Articles in Veterinary Infectious Diseases
Brown Dog Tick: Vector For Rocky Mountain Spotted Fever, Craig Levy
Brown Dog Tick: Vector For Rocky Mountain Spotted Fever, Craig Levy
Other Publications in Zoonotics and Wildlife Disease
The brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae), feeds primarily on dogs and until recently was not known to vector Rocky Mountain spotted fever (RMSF). In 2003–2004, fourteen cases of RMSF in humans occurred in eastern Arizona in the absence of known vectors, the Rocky Mountain wood tick, Dermacentor andersoni, and American dog tick, Dermacentor variabilis. However, health officials found brown dog ticks to be very abundant in areas associated with human cases, and the Centers for Disease Control and Prevention (CDC) implicated that the brown dog tick was responsible for transmitting RMSF. Brown dog ticks occur throughout the United …
Myenteric Neurons Of The Ileum That Express Somatostatin Are A Target Of Prion Neuroinvasion In An Alimentary Model Of Sheep Scrapie, David A. Schneider, Huijun Yan, Lindsay M. Fry, Janet Alverson, Stephen N. White, Katherine I. O'Rourke
Myenteric Neurons Of The Ileum That Express Somatostatin Are A Target Of Prion Neuroinvasion In An Alimentary Model Of Sheep Scrapie, David A. Schneider, Huijun Yan, Lindsay M. Fry, Janet Alverson, Stephen N. White, Katherine I. O'Rourke
Other Publications in Zoonotics and Wildlife Disease
Neuroinvasion of the enteric nervous system by prions is an important step in dissemination to the brain, yet very little is known about the basic process of enteric neuroinvasion. Using an alimentary model of neonatal disease transmission, neuroinvasion by scrapie prions in the ileum of lambs was detected by immunohistochemical staining for the disease-associated form of the prion protein, PrPSc. Odds ratios (OR) were determined for the frequency of PrPSc staining within enteric somata categorized by plexus location (myenteric, submucosal) and neurochemical staining (PGP 9.5, neural nitric oxide synthase, somatostatin, substance P, and vasoactive intestinal polypeptide). PrP …
Scrapie Resistance In Arq Sheep, W. W. Laegreid, M. L. Clawson, M. P. Heaton, B. T. Green, Katherine I. O'Rourke, D. P. Knowles
Scrapie Resistance In Arq Sheep, W. W. Laegreid, M. L. Clawson, M. P. Heaton, B. T. Green, Katherine I. O'Rourke, D. P. Knowles
Other Publications in Zoonotics and Wildlife Disease
Variation in the ovine prion protein amino acid sequence influences scrapie progression, with sheep homozygous for A136R154Q171 considered susceptible. This study examined the association of survival time of scrapie-exposed ARQ sheep with variation elsewhere in the ovine prion gene. Four single nucleotide polymorphism alleles were associated with prolonged survival. One nonsynonymous allele (T112) was associated with an additional 687 days of survival for scrapie-exposed sheep compared to M112 sheep (odds ratio, 42.5; P = 0.00014). The only two sheep homozygous for T112 (TARQ) did not develop scrapie, suggesting that the allelic effect may be additive. …
Ecological Factors Associated With West Nile Virus Transmission, Northeastern United States, Heidi E. Brown, James E. Childs, Maria A. Diuk-Wasser, Durland Fish
Ecological Factors Associated With West Nile Virus Transmission, Northeastern United States, Heidi E. Brown, James E. Childs, Maria A. Diuk-Wasser, Durland Fish
Other Publications in Zoonotics and Wildlife Disease
Since 1999, West Nile virus (WNV) disease has affected the northeastern United States. To describe the spatial epidemiology and identify risk factors for disease incidence, we analyzed 8 years (1999–2006) of county-based human WNV disease surveillance data. Among the 56.6 million residents in 8 northeastern states sharing primary enzootic vectors, we found 977 cases. We controlled for population density and potential bias from surveillance and spatial proximity. Analyses demonstrated significant spatial spreading from 1999 through 2004 (p2 = 0.16). A significant trend was apparent among increasingly urban counties; county quartiles with the least (0.75 cases/100,000 residents) than counties with the …
Prion Gene (Prnp) Haplotype Variation In United States Goat Breeds, Stephen N. White, Lynn Herrmann-Hoesing, Katherine I. O'Rourke, Daniel Waldron, Joan Rowe, Janet Alverson
Prion Gene (Prnp) Haplotype Variation In United States Goat Breeds, Stephen N. White, Lynn Herrmann-Hoesing, Katherine I. O'Rourke, Daniel Waldron, Joan Rowe, Janet Alverson
Other Publications in Zoonotics and Wildlife Disease
Scrapie eradication efforts cost 18 million dollars annually in the United States and rely heavily upon PRNP genotyping of sheep. Genetic resistance might reduce goat scrapie and limit the risk of goats serving as a scrapie reservoir, so PRNP coding sequences were examined from 446 goats of 10 breeds, 8 of which had not been previously examined at PRNP. The 10 observed alleles were all related to one of two central haplotypes by a single amino acid substitution. At least five of these alleles (M142, R143, S146, H154, and K222) have been associated with increased incubation time or decreased …
A Species Barrier Limits Transmission Of Chronic Wasting Disease To Mink (Mustela Vison), Robert D. Harrington, Timothy V. Baszler, Katherine I. O'Rourke, David A. Schneider, Terry R. Spraker, H. Denny Liggitt, Donald P. Knowles
A Species Barrier Limits Transmission Of Chronic Wasting Disease To Mink (Mustela Vison), Robert D. Harrington, Timothy V. Baszler, Katherine I. O'Rourke, David A. Schneider, Terry R. Spraker, H. Denny Liggitt, Donald P. Knowles
Other Publications in Zoonotics and Wildlife Disease
Transmissible mink encephalopathy (TME) occurs as sporadic outbreaks associated with ingestion of feed presumably contaminated with some type of prion disease. Mink lack a species barrier to primary oral challenge with bovine spongiform encephalopathy, whereas they have a barrier to such challenge with scrapie. We investigated whether mink have a species barrier to chronic wasting disease (CWD) by performing primary intracerebral (IC) and primary oral challenge with CWD-positive elk brain. Primary IC challenge resulted in clinical disease in two of eight mink at 31–33 months incubation. Affected mink had spongiform vacuolation and astrocytosis within the central nervous system and immunoreactivity …
Small-Ruminant Lentivirus Enhances PrpSc Accumulation In Cultured Sheep Microglial Cells, James B. Stanton, Donald P. Knowles, Katherine I. O'Rourke, Lynn M. Herrmann-Hoesing, Bruce A. Mathison, Timothy V. Baszler
Small-Ruminant Lentivirus Enhances PrpSc Accumulation In Cultured Sheep Microglial Cells, James B. Stanton, Donald P. Knowles, Katherine I. O'Rourke, Lynn M. Herrmann-Hoesing, Bruce A. Mathison, Timothy V. Baszler
Other Publications in Zoonotics and Wildlife Disease
Sheep scrapie is the prototypical transmissible spongiform encephalopathy (prion disease), which has a fundamental pathogenesis involving conversion of normal cellular prion protein (PrPC [C superscript stands for cellular]) to disease-associated prion protein (PrPSc [Sc superscript stands for sheep scrapie]). Sheep microglial cell cultures, derived from a prnp 136VV/171QQ near-term fetal brain, were developed to study sheep scrapie in the natural host and to investigate potential cofactors in the prion conversion process. Two culture systems, a primary cell culture and a cell line transformed with the large T antigen of simian virus 40, were developed, and both were identified …
Chronic Wasting Disease In A Wisconsin White-Tailed Deer Farm, Delwyn P. Keane, Daniel J. Barr, Phillip N. Bochsler, S. Mark Hall, Thomas Gidlewski, Katherine I. O'Rourke, Terry R. Spraker, Michael D. Samuel
Chronic Wasting Disease In A Wisconsin White-Tailed Deer Farm, Delwyn P. Keane, Daniel J. Barr, Phillip N. Bochsler, S. Mark Hall, Thomas Gidlewski, Katherine I. O'Rourke, Terry R. Spraker, Michael D. Samuel
Other Publications in Zoonotics and Wildlife Disease
In September 2002, chronic wasting disease (CWD), a prion disorder of captive and wild cervids, was diagnosed in a white-tailed deer (Odocoileus virginianus) from a captive farm in Wisconsin. The facility was subsequently quarantined, and in January 2006 the remaining 76 deer were depopulated. Sixty animals (79%) were found to be positive by immunohistochemical staining for the abnormal prion protein (PrPCWD) in at least one tissue; the prevalence of positive staining was high even in young deer. Although none of the deer displayed clinical signs suggestive of CWD at depopulation, 49 deer had considerable accumulation of …
A Collaborative Canadian–United Kingdom Evaluation Of An Immunohistochemistry Protocol To Diagnose Bovine Spongiform Encephalopathy, Lisa Manning, Katherine I. O'Rourke, Donald P. Knowles, Sarah A. Marsh, Yvonne I. Spencer, Estella Moffat, Gerald A. H. Wells, Stefanie Czub
A Collaborative Canadian–United Kingdom Evaluation Of An Immunohistochemistry Protocol To Diagnose Bovine Spongiform Encephalopathy, Lisa Manning, Katherine I. O'Rourke, Donald P. Knowles, Sarah A. Marsh, Yvonne I. Spencer, Estella Moffat, Gerald A. H. Wells, Stefanie Czub
Other Publications in Zoonotics and Wildlife Disease
Collaboration was established in 2001 to evaluate a commercially available immunohistochemistry assay kit for the detection of bovine spongiform encephalopathy (BSE) disease–associated prion protein in formic acid–treated formalin-fixed samples of bovine brain. The kit protocol was evaluated at the National Centre for Foreign Animal Diseases (Winnipeg, Canada) and the Veterinary Laboratories Agency (Weybridge, U.K.). The U.K. laboratory provided paraffin-embedded blocks of brainstem (medulla oblongata at the level of the obex) from 100 positive cases defined by clinical signs and histopathology, and 100 clinically suspect but BSE-negative samples defined by histopathology and immunohistochemistry with anti-PrP monoclonal antibody R145. The Canadian laboratory …
Experimental Transmission Of Chronic Wasting Disease (Cwd) Of Elk (Cervus Elaphus Nelsoni), White-Tailed Deer (Odocoileus Virginianus), And Mule Deer (Odocoileus Hemionus Hemionus) To White-Tailed Deer By Intracerebral Route, A. N. Hamir, J. A. Richt, J. M. Miller, R. A. Kunkle, S. M. Hall, E. M. Nicholson, Katherine I. O'Rourke, J. J. Greenlee, E. S. Williams
Experimental Transmission Of Chronic Wasting Disease (Cwd) Of Elk (Cervus Elaphus Nelsoni), White-Tailed Deer (Odocoileus Virginianus), And Mule Deer (Odocoileus Hemionus Hemionus) To White-Tailed Deer By Intracerebral Route, A. N. Hamir, J. A. Richt, J. M. Miller, R. A. Kunkle, S. M. Hall, E. M. Nicholson, Katherine I. O'Rourke, J. J. Greenlee, E. S. Williams
Other Publications in Zoonotics and Wildlife Disease
To compare clinical and pathologic findings of chronic wasting disease (CWD) in a natural host, 3 groups (n = 5) of white-tailed deer (WTD) fawns were intracerebrally inoculated with a CWD prion of WTD, mule deer, or elk origin. Three other uninoculated fawns served as controls. Approximately 10 months postinoculation (MPI), 1 deer from each of the 3 inoculated groups was necropsied and their tissues were examined for lesions of spongiform encephalopathy (SE) and for the presence of abnormal prion protein (PrPd) by immunohistochemistry (IHC) and Western blot (WB). The remaining deer were allowed to live until …