WDIN New Content

White-Tailed Deer Movements in a Chronic Wasting Disease Area in South-Central Wisconsin

Tue, 08 Jul 2008 00:00:00 -0500

From abstract (online abstract only):To focus white-tailed deer (Odocoileus virginianus) management within a chronic wasting disease - infected area in south-central Wisconsin, USA, we assessed deer movements and related dispersal to variation in landscape pattern, deer density, and harvest intensity. We radiocollared and monitored 165 deer between 2003 and 2005. Yearling males that dispersed (45%) had greater forest edge (i.e., fragmentation) within natal home ranges. Exploratory movements were rare for adult females. Transient and migratory movements were rare among all deer (<5%). Although yearling males have low chronic wasting disease prevalence rates, they may be infected before dispersal due to variable incubation times. Managers should increase yearling male harvest and consider removing young males in areas of higher forest edge.

Quarantine and Health Screening Protocols for Wildlife prior to Translocation and Release into the Wild

Wed, 18 Jun 2008 00:00:00 -0500

In an effort to address the disease considerations of wild animal releases, Michael Woodford has assembled information regarding quarantine, screening procedures and treatment/vaccination suggestions for mammals, birds, reptiles, amphibians and fish. These protocols are comprehensive and represent the ideal, given our current level of understanding of the potential risks of the various organisms that may be carried by any single animal. We are reminded that once an animal has been released into the wild, it is rarely, if ever, possible to recover that animal or the potential pathogens it may be carrying. Thus it is incumbent upon all who are charged with the release of wildlife to follow stringent guidelines that will help to ensure the merit and wisdom of releasing such wildlife.

"Quarantine and Health Screening Protocols for Wildlife Prior to Translocation to Release into the Wild" is an excellent reference source and will enable the veterinarian to make rational decisions regarding release based on currently available science. Michael Woodford and his fellow contributors are to be congratulated for their thoughtful approach to this subject.

Australian Wildlife Health Network - Disease Incident Reports

Wed, 18 Jun 2008 00:00:00 -0500

As part of the Australian Wildlife Health Network web site, this section offers brief, summary information on selected disease events occurring around Australia.

Wildlife Disease Association Newsletter Archives

Wed, 18 Jun 2008 00:00:00 -0500

Lists back issues of the Wildlife Disease Association (WDA) newsletter. This publication is written for WDA members to keep them updated on the organization's activities, upcoming wildlife disease related meetings and conferences, and future education opportunities. Non-members who have an interest in the topic of wildlife disease will also find this resource informative, especially the section, News from the Field, which includes the Quarterly Wildlife Mortality Report from the National Wildlife Health Center. This section provides a review of disease outbreaks that occurred during the reported quarter in the form of brief narratives and a summery table, which includes information such as location, dates, species affected, and diagnosis.

Serologic Survey of Birds for West Nile Flavivirus in Southern Moravia (Czech Republic)

Fri, 16 May 2008 00:00:00 -0500

From abstract (online abstract only): A serosurvey for West Nile virus (WNV) was carried out in 54 domestic birds (geese and ducks bred on fishponds) and 391 wild birds representing 28 migratory and resident species, using a plaque-reduction neutralization microtest with Vero cells and Egyptian topotype Eg-101 strain as test virus. The birds were sampled in the South-Moravian fishpond ecosystem between 2004 and 2006. Antibodies to WNV were not detected in domestic waterfowl, but 23 (5.9%) free-living birds of 10 species showed a positive response. These were the common coot (Fulica atra, 5 positive/18 examined), common kingfisher (Alcedo atthis, 1/1), reed warbler (Acrocephalus scirpaceus, 2/80), sedge warbler (A. schoenobaenus, 3/80), marsh warbler (A. palustris, 2/28), Savi's warbler (Locustella luscinioides, 3/12), reed bunting (Emberiza schoeniclus, 1/28), blackcap (Sylvia atricapilla, 2/11), penduline tit (Remiz pendulinus, 1/14), blue tit (Parus caeruleus, 1/1), and starling (Sturnus vulgaris, 2/4). The antibody titers were comparatively low (1:20-1:40), and the only high titer (1:160) was found in an adult marsh warbler. When 14 of the sera reacting with WNV were titrated in parallel with Usutu Flavivirus, 12 were interpreted as having specific antibodies to WNV, one coot had a higher titer against Usutu virus, and another one could not be attributed to either of the two viruses. In conclusion, 13 (3.3%) of 391 wild birds had specific antibodies to WNV. The results indicate that WNV activity in southern Moravia was limited during 2004 - 2006.

PrP Genotypes of Free-Ranging Wapiti (Cervus elaphus nelsoni) with Chronic Wasting Disease

Wed, 14 May 2008 00:00:00 -0500

Variation in PrP prion gene sequence appears to modulate susceptibility to chronic wasting disease (CWD), a naturally occurring prion disease affecting four North American species of the family Cervidae. Wapiti (Cervus elaphus nelsoni) PrP is polymorphic at codon 132 [methionine (M) or leucine (L)]. We genotyped 171 samples, collected between 2002 and 2005 from CWD-infected and uninfected wapiti from three free-ranging populations in Colorado, USA, to study influences of PrP polymorphisms on CWD susceptibility further. Overall genotype frequencies for 124 apparently uninfected animals were 65.3 % MM132, 32.3 % ML132 and 2.4 % LL132; for 47 CWD-infected animals, these frequencies were 70.2 % MM132, 27.7 % ML132 and 2.1 % LL132. Surprisingly, our data revealed that, among recent (approx. 2002-2005) CWD cases detected in free-ranging Colorado wapiti, the three PrP codon 132 genotypes were represented in proportion to their abundance in sampled populations (P greater than 0.24) and all three genotypes showed equivalent susceptibility to infection.

Enviro-Health Links - Lead and Human Health - Wild Birds and Lead Shot or Sinkers

Mon, 28 Apr 2008 00:00:00 -0500

Provides an extensive bibliography of web links on lead poisoning, most pertaining to human health. Although, there is a section on wild birds under the heading, Specific Aspects, entitled, Wild birds and Lead Shot and Sinkers. Here visitors will find a substantial list of web resources, including links to a chapter on lead in the National Wildlife Health Center, Field Manual of Wildlife Disease and a U.S. Geological Survey map on bird deaths due to lead poisoning.

Hunter Perceptions of Similarity and Trust in Wildlife Agencies and Personal Risk Associated with Chronic Wasting Disease

Mon, 28 Apr 2008 00:00:00 -0500

From abstract (online abstract only): Theory suggests that risk perceptions are influenced by trust in managing agencies. Shared goals and values (i.e., perceived similarity) are foundations of trust. This article examines the extent to which hunters perceive personal health risks associated with chronic wasting disease (CWD) (e.g., become ill from CWD) and the influence of perceived similarity and trust in state wildlife agencies as determinants of risk. Data were obtained from surveys (n = 9567) of resident and nonresident deer and elk hunters in eight states. Structural equation models showed that across all strata, hunters' perceptions of similarity with agencies positively influenced trust in agencies to manage CWD, explaining up to 49% of the variance in trust. Hunters who trusted agencies perceived less risk associated with CWD, but trust only explained up to 8% of the variance in risk. Hunters perceived similarity with and trust in wildlife agencies, but still perceived risks associated with CWD.

CWD Regulations in North America - Use a Map to Find Regulation Summaries for State and Provincial Agenices

Mon, 14 Apr 2008 00:00:00 -0500

Transportation regulations for deer and other cervid carcasses are regularly amended. With this easy-to-use map interface, hunters and other interested individuals can quickly click on a map and access not only contact information for a particular state or provincial CWD (chronic wasting disease) management agency, but also learn about new CWD regulations in development, current CWD testing programs, and feeding bans.

Shedding Light on Chronic Wasting Disease [Video]

Mon, 14 Apr 2008 00:00:00 -0500

From introduction: Produced in cooperation with American Outdoor Productions, this instructional video [for hunters] entitled "Shedding Light on Chronic Wasting Disease" discusses important facts about CWD and provides: 1) Close-up views of lymph nodes and their locations, 2) A 3D model illustrating the CWD hot spots in a deer and elk, 3) A hunter, in the field, demonstrating the boning-out of a deer and removal of the tissues where CWD is found, 4) A home processing section showing how to eliminate any of the remaining potentially diseased areas, 5) Suggested care that should be taken by the professional processor, 6)Footage portraying CWD symptoms in live animals, 7)Procedure for presenting a proper sample for testing, 8) The proper way to hang an animal in CWD areas, 9) A brief historical perspective from an individual who saw some of the first recorded cases, 10)An interview with the late Beth Williams, one of the top authorities who originally diagnosed CWD and her thoughts on hunting in CWD areas, 11)Advice on compliance with state carcass transportation regulations. [copyright 2004].

Wild Ducks as Long-Distance Vectors of Highly Pathogenic Avian Influenza Virus (H5N1)

Mon, 14 Apr 2008 00:00:00 -0500

From abstract (free full-text available):Wild birds have been implicated in the expansion of highly pathogenic avian influenza virus (H5N1) outbreaks across Asia, the Middle East, Europe, and Africa (in addition to traditional transmission by infected poultry, contaminated equipment, and people). Such a role would require wild birds to excrete virus in the absence of debilitating disease. By experimentally infecting wild ducks, we found that tufted ducks, Eurasian pochards, and mallards excreted significantly more virus than common teals, Eurasian wigeons, and gadwalls; yet only tufted ducks and, to a lesser degree, pochards became ill or died. These findings suggest that some wild duck species, particularly mallards, can potentially be long-distance vectors of highly pathogenic avian influenza virus (H5N1) and that others, particularly tufted ducks, are more likely to act as sentinels. [includes figures].

Transmission of Avian Influenza Virus (H3N2) to Dogs

Wed, 02 Apr 2008 00:00:00 -0600

From abstract (free full-text available): In South Korea, where avian influenza virus subtypes H3N2, H5N1, H6N1, and H9N2 circulate or have been detected, 3 genetically similar canine influenza virus (H3N2) strains of avian origin (A/canine/Korea/01/07, A/canine/Korea/02/07, and A/canine/Korea/03/07) were isolated from dogs exhibiting severe respiratory disease. To determine whether the novel canine influenza virus of avian origin was transmitted among dogs, we experimentally infected beagles with this influenza virus (H3N2) isolate. The beagles shed virus through nasal excretion, seroconverted, and became ill with severe necrotizing tracheobronchitis and bronchioalveolitis with accompanying clinical signs (e.g., high fever). Consistent with histologic observation of lung lesions, large amounts of avian influenza virus binding receptor (SAa 2,3-gal) were identified in canine tracheal, bronchial, and bronchiolar epithelial cells, which suggests potential for direct transmission of avian influenza virus (H3N2) from poultry to dogs. Our data provide evidence that dogs may play a role in interspecies transmission and spread of influenza virus.

Avian Flu: Threat of a pandemic [Video]

Wed, 02 Apr 2008 00:00:00 -0600

The risk from avian flu is generally low to most people. However, scientists are concerned that the H5N1 virus could one day be able to infect humans and spread easily from one person to another. We will explain how the virus which is today very contagious to birds may become tomorrow very contagious to humans. Also includes outline of video. Approximately 8 minutes.

Age-related Lesions in Laboratory-confined Raccoons (Procyon lotor) Inoculated with the Agent of Chronic Wasting Disease of Mule Deer

Tue, 01 Apr 2008 00:00:00 -0600

From abstract: (online abstract only): This communication documents age-associated pathologic changes and final observations on experimental transmission of chronic wasting disease (CWD) by the intracerebral route to raccoons (Procyon lotor). Four kits were inoculated intracerebrally with a brain suspension from mule deer with CWD. Two uninoculated kits served as controls. One CWD-inoculated raccoon was humanely killed at 38 months after inoculation, and 1 control animal died at 68 months after inoculation. Both animals had lesions that were unrelated to transmissible spongiform encephalopathy. Six years after inoculation, none of the 3 remaining CWD-inoculated raccoons had shown clinical signs of neurologic disorder, and the experiment was terminated. Spongiform encephalopathy was not observed by light microscopy, and the presence of abnormal prion protein (PrPd) was not detected by either immunohistochemistry or Western blot techniques. Age-related lesions observed in these raccoons included islet-cell pancreatic amyloidosis (5/6), cystic endometrial hyperplasia (3/4), cerebrovascular mineralization (5/6), neuroaxonal degeneration (3/6), transitional-cell adenoma of the urinary bladder (1/6), and myocardial inclusions (4/6). The latter 2 pathologic conditions were not previously reported in raccoons.

H5N1 Avian Influenza Re-emergence of Lake Qinghai: Phylogenetic and Antigenic Analyses of the Newly Isolated Viruses and Roles of Migratory Birds in Virus Circulation

Mon, 31 Mar 2008 00:00:00 -0600

From abstract (free full-text available): Highly pathogenic avian influenza H5N1 virus has swept west across the globe and caused serious debates on the roles of migratory birds in virus circulation since the first large-scale outbreak in migratory birds of Lake Qinghai, 2005. In May 2006, another outbreak struck Lake Qinghai and six novel strains were isolated. To elucidate these QH06 viruses, the six isolates were subjected to whole-genome sequencing. Phylogenetic analyses show that QH06 viruses are derived from the lineages of Lake Qinghai, 2005. Five of the six novel isolates are adjacent to the strain A/Cygnus olor/Croatia/1/05, and the last one is related to the strain A/duck/Novosibirsk/02/05, an isolate of the flyway. Antigenic analyses suggest that QH06 and QH05 viruses are similar to each other. These findings implicate that QH06 viruses of Lake Qinghai may travel back via migratory birds, though not ruling out the possibility of local circulation of viruses of Lake Qinghai. [includes figures].

Mapping H5N1 highly pathogenic avian influenza risk in Southeast Asia

Fri, 28 Mar 2008 00:00:00 -0600

From abstract (free full-text available): The highly pathogenic avian influenza (HPAI) H5N1 virus that emerged in southern China in the mid-1990s has in recent years evolved into the first HPAI panzootic. In many countries where the virus was detected, the virus was successfully controlled, whereas other countries face periodic reoccurrence despite significant control efforts. A central question is to understand the factors favoring the continuing reoccurrence of the virus. The abundance of domestic ducks, in particular free-grazing ducks feeding in intensive rice cropping areas, has been identified as one such risk factor based on separate studies carried out in Thailand and Vietnam. In addition, recent extensive progress was made in the spatial prediction of rice cropping intensity obtained through satellite imagery processing. This article analyses the statistical association between the recorded HPAI H5N1 virus presence and a set of five key environmental variables comprising elevation, human population, chicken numbers, duck numbers, and rice cropping intensity for three synchronous epidemic waves in Thailand and Vietnam. A consistent pattern emerges suggesting risk to be associated with duck abundance, human population, and rice cropping intensity in contrast to a relatively low association with chicken numbers. A statistical risk model based on the second epidemic wave data in Thailand is found to maintain its predictive power when extrapolated to Vietnam, which supports its application to other countries with similar agro-ecological conditions such as Laos or Cambodia. The model's potential application to mapping HPAI H5N1 disease risk in Indonesia is discussed [includes figures].

Avian Flu: The H5N1 virus [Video]

Mon, 24 Mar 2008 00:00:00 -0600

From podcast description: Following the most recent outbreak of bird flu in British turkeys, we decided to focus on the H5N1 virus. Avian flu refers to influenza viruses found in birds. The risk from avian flu is generally low to most people. However, confirmed cases of human infection from an avian influenza virus called H5N1 have been reported since 1997. Scientists are concerned that H5N1 virus one day could be able to infect humans and spread easily from one person to another. Also included outline of video. Approximately 7 minutes.

Detection and Isolation of H5N1 Influenza Vrus from Large Volumes of Natural Water

Mon, 24 Mar 2008 00:00:00 -0600

From abstract (online abstract only): Various species of aquatic or wetlands birds can be the natural reservoir of avian influenza A viruses of all hemagglutinin (HA) subtypes. Shedding of the virus into water leads to transmission between waterfowl and is a major threat for epidemics in poultry and pandemics in humans. Concentrations of the influenza virus in natural water reservoirs are often too low to be detected by most methods. The procedure was designed to detect and isolate low concentrations of the influenza virus in large volumes of water without the need for costly installations and reagents. The virus was adsorbed onto formalin-fixed erythrocytes and subsequently isolated in chicken embryos. Sensitivity of the method was determined using a reverse-genetic H5N1 virus. A concentration as low as 0.03 of the 50% egg infection dose per milliliter (EID50/ml) of the initial volume of water was effectively detected. The probability of detection was around 13%, which is comparable to that of detecting the influenza virus M-gene by PCR amplification. The method can be used by field workers, ecologists, ornithologists, and researchers who need a simple method to isolate H5N1 influenza virus from natural reservoirs. The detection and isolation of virus in embryonated chicken eggs may help epidemiologic, genetic, and vaccine studies.

Examining the Hemagglutinin Subtype Diversity Among Wild Duck-origin Influenza A Viruses Using Ethanol-fixed Cloacal Swabs and a Novel RT-PCR Method

Mon, 24 Mar 2008 00:00:00 -0600

From abstract (online abstract only): This study presents an interconnected approach for circumventing two inherent limitations associated with studies defining the natural history of influenza A viruses in wild birds. The first limiting factor is the ability to maintain a cold chain from specimen collection to the laboratory when study sites are in more remote locations. The second limiting factor is the ability to identify all influenza A virus HA subtypes present in an original sample. We report a novel method for molecular subtyping of avian influenza A virus hemagglutinin genes using degenerate primers designed to amplify all known hemagglutinin subtypes. It was shown previously that templates larger than 200 bp were not consistently amplifiable from ethanol-fixed cloacal swabs. For this study, new primer sets were designed within these constraints. This method was used to perform subtyping RT-PCR on 191 influenza RNA-positive ethanol-fixed cloacal swabs obtained from 880 wild ducks in central Alaska in 2005. Seven different co-circulating hemagglutinin subtypes were identified in this study set, including H1, H3, H4, H5, H6, H8, and H12. In addition, 16% of original cloacal samples showed evidence of mixed infection, with samples yielding from two-to-five different hemagglutinin subtypes. This study further demonstrates the complex ecobiology of avian influenza A viruses in wild birds.

Preliminary Observations on the Experimental Transmission of Chronic Wasting Disease (CWD) from Elk and White-Tailed Deer to Fallow Deer

Mon, 24 Mar 2008 00:00:00 -0600

From abstract (online abstract only): To determine the transmissibility of chronic wasting disease (CWD) to fallow deer (Dama dama) and to provide information about clinical course, lesions and suitability of currently used diagnostic procedures for detection of CWD in this species, 13 fawns were inoculated intracerebrally with CWD brain suspension from elk (n = 6) or white-tailed deer (n = 7). Three other fawns were kept as uninfected controls. Three CWD-inoculated deer were killed 7.6 months post-inoculation (mpi). None had abnormal prion protein (PrPd) in their tissues. One sick deer died at 24 mpi and one deer without clinical signs was killed at 26 mpi. Both animals had a small focal accumulation of PrPd in the midbrain. Between 29 and 37 mpi, three other deer became sick and were killed. All had shown gradual decrease in appetite and some loss of body weight. Microscopical lesions of spongiform encephalopathy were not observed, but PrPd was detected in tissues of the central nervous system (CNS) by immunohistochemistry, western blot and by two commercially available rapid diagnostic tests. This study demonstrates that intracerebrally inoculated fallow deer amplified CWD PrPd from white-tailed deer and elk in the absence of lesions of spongiform encephalopathy. Four years after CWD inoculation, the remaining five inoculated and two control deer are alive and apparently healthy.