Expression of interleukin-1 beta and interleukin-6 in white-tailed deer infected with Epizootic Hemorrhagic Disease virus.

The pathogenesis of epizootic haemorrhagic disease (EHD) in white­tailed deer (WTD) may be related to factors other than direct viral damage caused by replication in endothelium, such as the release of cytokines. This study focused on interleukin­1 ß (IL­1) and interleukin­6 (IL­6), which have been shown to be variably upregulated in Bluetongue virus (BTV) infected cattle and sheep endothelial cultures possibly explaining species susceptibility to BTV. We evaluated circulating and tissue levels of IL­1 and IL­6 in WTD experimentally infected with EHD virus serotype 2 (EHDV­2). Circulating levels of IL­1 were assayed by ELISA. RT­PCR and immunohistochemistry (IHC) were used to detect upregulation of IL­1 and IL­6 mRNA as well as protein expression, respectively. RT­PCR was also used to determine whether IL­1 and IL­6 were upregulated in WTD peripheral blood mononuclear cells (PBMC) infected with EHDV­2 in vitro. We found increased circulating levels of IL­1 and upregulation of IL­1 mRNA and protein expression and upregulation of IL­6 mRNA in tissues of WTD infected with EHDV. Upregulation of mRNA levels of IL­1 and IL­6 in EHDV infected PBMCs was also observed. Findings suggest a role for IL­1 and IL­6 in the pathogenesis of EHD in WTD.

Assessment of owner willingness to treat or manage diseases of dogs and cats as a guide to shelter animal adoptability.

OBJECTIVE: To determine community approaches to medical and behavioral diseases in dogs and cats. DESIGN: Cross-sectional descriptive study. SAMPLE: 97 companion animal veterinarians and 424 animal owners. PROCEDURES: Companion animal veterinarians in central Iowa ranked medical or behavioral diseases or conditions by what they thought most clients would consider healthy, treatable, manageable, or unhealthy (unmanageable or untreatable). In a parallel survey, cat- or dog-owning households in central Iowa responded to a telephone survey regarding the relationship of their animal in the household, owner willingness to provide medical or behavioral interventions, and extent of financial commitment to resolving diseases. RESULTS: One hundred twenty common health or behavioral disorders in cats and dogs were ranked by veterinarians as healthy, treatable, manageable, or unhealthy (unmanageable or untreatable) on the basis of their opinion of what most clients would do. Findings were in congruence with animal owners' expressed willingness to provide the type of care required to maintain animals with many acute or chronic medical and behavioral conditions. In general, owners indicated a willingness to use various treatment modalities and spend money on veterinary services when considering current or previously owned animals as well as hypothetical situations with an animal. Past experiences with veterinary care in which an animal did not recover fully did not diminish the willingness of respondents to use veterinary services again in the future. CONCLUSIONS AND CLINICAL RELEVANCE: These results provide a baseline indication of community willingness to address medical or behavioral conditions in dogs and cats. These considerations can be used in conjunction with Asilomar Accords recommendations to assess adoptability of cats and dogs in animal shelters.

Molecular characterization of epizootic hemorrhagic disease virus serotype 1 associated with a 1999 epizootic in white-tailed deer in the eastern United States.

During the autumn of 1999 (mid-August-late September), an outbreak of hemorrhagic disease in white-tailed deer (Odocoileus virginianus) caused by epizootic hemorrhagic disease virus serotype 1 (EHDV-1) occurred along the east coast of the United States from Georgia to New Jersey. An EHDV-1 epizootic of such magnitude had not been described in this region since 1975. To determine the genetic relatedness among the 1999 viruses, as well as among additional EHDV-1 isolates from the eastern and western United States, portions of the S10 and L2 gene segments were sequenced and compared utilizing phylogenetic analyses. Nearly all of the 1999 eastern isolates were identical in nucleotide sequence at one or both loci. Additionally, confirmed cases of EHDV-1 in white-tailed deer occurred in a south (Georgia)-to-north (New Jersey/Virginia) progression over a short period of approximately six weeks. Taken together, these results indicate that this outbreak resulted from the spread of a single viral strain. The phylograms derived from analysis of the entire sample set displayed eastern and western region-specific clusterings (topotypes), as well as an eastern versus western difference in branch lengths, which may reflect the influence of epizootic versus enzootic transmission patterns on viral genetic diversity.

Genetic variation among epizootic hemorrhagic disease viruses in the southeastern United States: 1978-2001.

The epizootic hemorrhagic disease (EHD) viruses, which are endemic in the southeastern United States, are the causative agents of an important clinical disease in wild and captive ruminants. In order to elucidate the molecular epidemiology of EHD serotype 2, the sequences of portions of the S10 and L2 gene segments (which encode the NS3 viral egress protein and the VP2 surface protein, respectively) of viral isolates made from white-tailed deer over 23 years(1978-2001) were determined and compared using phylogenetic analyses. Both loci demonstrated very little genetic variation among isolates, with a 94-100% nucleotide identity among isolates at the S10 locus (98-100% amino acid conservation), and an 89.1-100% identity among isolates at the L2 locus (87.6-100% amino acid conservation). The grouping of isolates within the resulting cladograms appeared nearly random with respect to time of isolation and geographic origin. One exception to this was a distinctive grouping of some isolates from 1996 to 1997, which formed a separate subclade in both the S10 and L2 cladograms.

Effect of strain and serotype of vesicular stomatitis virus on viral shedding, vesicular lesion development, and contact transmission in pigs.

OBJECTIVE: To determine whether pigs can be infected with strains of vesicular stomatitis virus New Jersey (VSV-NJ) and vesicular stomatitis virus Indiana (VSV-I) isolated during recent vesicular stomatitis outbreaks that primarily involved horses in the western United States and determine the potential for these viruses to be transmitted by contact. ANIMALS: 128 pigs. PROCEDURE: Pigs were challenged with VSV-NJ or VSV-I from the 1995 and 1997 outbreaks of vesicular stomatitis in the western United States, respectively, or with VSV-NJ (OS) associated with vesicular stomatitis in feral pigs on Ossabaw Island, Ga. Pigs (3/group) were inoculated with each virus via 3 routes and evaluated for viral shedding, seroconversion, and the development of vesicular lesions. In another experiment, the potential for contact transmission of each virus from experimentally infected to naïve pigs was evaluated. RESULTS: Infection of pigs was achieved for all 3 viruses as determined by virus isolation and detection of seroconversion. In inoculated pigs, all 3 viruses were isolated from multiple swab samples at concentrations sufficient to infect other pigs. However, compared with results obtained with the 2 VSV-NJ strains, viral titers associated with VSV-I were low and the duration of virus shedding was reduced. Results from the contact transmission trials were consistent with these results; virus transmission was detected most frequently with the VSV-NJ strains. CONCLUSIONS AND CLINICAL RELEVANCE: Pigs can be infected with VSV-NJ and VSV-I. Differences in the extent of viral shedding and potential for contact transmission were apparent between serotypes but not between the VSV-NJ strains investigated.

Biological transmission of vesicular stomatitis virus (New Jersey serotype) by Simulium vittatum (Diptera: Simuliidae) to domestic swine (Sus scrofa).

The role of hematophagous arthropods in vesicular stomatitis virus (New Jersey serotype; VSV-NJ) transmission during epizootics has remained unclear for decades in part because it has never been shown that clinical or subclinical disease in a livestock host results from the bite of an infected insect. In this study, we investigated the ability of VSV-NJ-infected black flies (Simulium vittatum Zetterstedt) to transmit the virus to domestic swine, Sus scrofa L. Experimental evidence presented here clearly demonstrates that VSV-NJ was transmitted from black flies to the swine. Transmission was confirmed by seroconversion or by the presence of clinical vesicular stomatitis followed by seroconversion. Our results represent the first report of clinical vesicular stomatitis in a livestock host after virus transmission by an insect.

Black fly involvement in the epidemic transmission of vesicular stomatitis New Jersey virus (Rhabdoviridae: Vesiculovirus).

The transmission routes of Vesicular stomatitis New Jersey virus (VSNJV), a causative agent of vesicular stomatitis, an Office International des Epizooties List-A disease, are not completely understood. Epidemiological and entomological studies conducted during the sporadic epidemics in the western United States have identified potential virus transmission routes involving insect vectors and animal-to-animal contact. In the present study we experimentally tested the previously proposed transmission routes which were primarily based on field observations. Results obtained provide strong evidence for the following: (1) hematophagous insects acquire VSNJV by unconventional routes while blood feeding on livestock, (2) clinical course of VSNJV infection in livestock following transmission by an infected insect is related to insect bite site, (3) infection of livestock via insect bite can result in multiple transmission possibilities, including animal-to-animal contact. Taken together, these data significantly add to our understanding of the transmission routes of a causative agent of one of the oldest known infectious diseases of livestock, for which the details have remained largely unknown despite decades of research.