Recommendations of the International Roundtable Workshop on Bovine Spongiform Encephalopathy.

Recommendations of the working party were summarized as follows: Determine the status in all countries of their national cattle herds with respect to BSE. Attempt to develop a test to recognize BSE-infected animals before they become clinically ill. Establish procedures to prevent spread of BSE agent into the cattle populations, especially by eliminating feeds containing rendered ruminant proteins. Review the rendering processes, identify the sources and destinations of rendered products, and suggest appropriate changes if needed. Especially needed are standardized rendering procedures in regard to use of organic solvents, temperature, and duration of heat treatment. Review import and export regulations to reduce the risk of spreading BSE and to maximize opportunities for safe trading in cattle and cattle products. The scrapie-free certification program of the USDA was supported, and similar programs might be considered by other countries. If BSE/scrapie is diagnosed in a given country, determine baseline incidence of CJD in those countries and consider contributing to an international registry. The WHO should address the problems of BSE, formulate policy, participate in and coordinate research, and provide training opportunities for veterinary and human health care workers from eastern European countries and developing nations. Government and private agencies should consider increasing support for research on transmissibility and pathogenesis of CJD, BSE, CWD, scrapie, and transmissible mink encephalopathy. Prepare and publish a critical neuropathologic review of all spongiform encephalopathies, naturally and experimentally transmitted, defining the characteristics of each disease in the various species known to be susceptible. Consider producing guidelines for the biological and pharmaceutical industries with regard to sourcing, collecting, and processing bovine and ovine materials.(ABSTRACT TRUNCATED AT 250 WORDS)     

Veterinarian injuries associated with bovine TB testing livestock in Michigan, 2001

Testing all the cattle in an entire state with a uniform procedure for each animal affords an opportunity to relate human injury data to a known number of animals handled while carrying out a standardized procedure. Our objective was to describe the type and incidence density of injuries associated with TB-testing a large number of cattle herds, and to delineate the various factors associated with the risk of injury. A survey was mailed to all veterinarians (N = 259) who had completed at least five official bovine TB (bTB) herd tests in Michigan in 2001. We collected data regarding basic demographics and health status, work experience, veterinary specialty, and practice information. Each veterinarian was also requested to complete a separate injury questionnaire for each injury received while TB testing livestock in 2001. Accurate addresses were found for 247 eligible veterinarians, 175 (71%) of whom returned the survey. Thirty-six veterinarians reported a total of 53 injuries (10 major, 12 minor and 31 self-treated). Hands (29%) and legs (21%) were the anatomic locations most frequently injured, with sprains/strains (30%) and abrasion/contusion (30%) the most common types of injuries sustained. The overall incidence density of injuries was 1.9 per 10,000 animals tested. Female gender (RR = 3.3), being employed by the government (RR = 4.5), and smoking (RR = 6.0) were significantly associated with a higher rate of injury. Significant colliniearities were found between some risk factors associated with an increased rate of injury and participants thought 81% of their injuries could have been prevented. These results are explained by the administrative structure of the bTB testing program in Michigan, and the changing demographics of the veterinary workforce.     

Isolation and identification of canine adenovirus type-2 from the upper respiratory tract of a dog

AIM: To report on the isolation and identification of canine adenovirus type-2 (CAV-2) from a greyhound dog with tracheitis/tonsillitis. METHODS: Virus isolation was performed with Madin and Darby canine kidney (MDCK) cell monolayers using standard virological techniques. The isolated virus was identified by haemagglutination inhibition and serum neutralisation tests. Viral DNA was extracted from infected MDCK cells and subjected to restriction endonuclease analysis using the endonuclease enzymes Bam HI, Bgl II, Eco RI and Hind III. RESULTS: A virus, designated 5 113-87, was isolated in MDCK cells yielding typical cytopathic effect. The virus could be neutralised with a CAV-2 specific reference antiserum and also showed some cross neutralisation with CAV-1 specific reference antiserum. The virus 5 113-87 had a high haemagglutination inhibition titre with CAV-2 antiserum using human group 0 red blood-cells and CAV-1 and CAV-2 reference antisera. This virus also had DNA restriction profiles identical to those of the reference CAV-2 (Toronto A26/61), whereas previously isolated strains of adenovirus from dogs in New Zealand had DNA restriction patterns identical to the prototype CAV-1 strain (Utrecht). CONCLUSION: The findings show that the virus 5 113-87 isolated from the upper respiratory tract of a dog in New Zealand is CAV-2.     

In Vitro Production of Equine Embryos

The development of methods to produce embryos in vitro in the horse has been delayed compared with other domestic species. Oocytes can be collected from excised ovaries or from the small or preovulatory follicles of live mares. Intracytoplasmic sperm injection is the only reliable method to fertilize equine oocytes in vitro. Intracytoplasmic sperm injection-produced embryos can be transferred into the oviducts of recipient mares or cultured to the morula or blastocyst stage of development for nonsurgical embryo transfers into recipients' uteri. Embryos cultured in vitro have some morphological differences compared with embryos collected from the mares' uteri. Most notably, the embryonic capsule does not form in culture, and the zona pellucida fails to expand completely. However, embryo produced in vitro can result in viable pregnancies and healthy offspring.     

Malachite green therapy of proliferative kidney disease in rainbow trout: field trials

The results of a series of experiments to investigate the use of the arylmethane dye, malachite green, for the control of proliferative kidney disease in rainbow trout (Salmo gairdneri Richardson) are described. Under field conditions using the bath application method the dye gave good control of the disease with treatments at 1.6 ppm for 40 minutes repeated at seven, 14 and 21 day intervals. Flush treatments were also successful using the same treatment intervals and beginning with 3.2 ppm malachite green. The problems of toxicity and of standardising the exposure of the fish to the dye with flush treatments are discussed.     

Epizootic haematopoietic necrosis virus—An assessment of the likelihood of introduction and establishment in England and Wales

Epizootic haematopoietic necrosis virus (EHNV) is an iridovirus that affects perch (Perca fluviatilis) and rainbow trout (Oncorhynchus mykiss). It emerged in Australia in the 1980s and has not been discovered elsewhere. It causes a high level of mortality in perch resulting in steep population declines. The main possible routes of introduction of the virus to England and Wales are the importation of infected live fish or carcasses. However, no trade in live susceptible species is permitted under current legislation, and no importation of carcasses currently takes place. The virus is hardy and low levels of challenge can infect perch. Therefore, mechanical transmission through the importation of non-susceptible fish species should be considered as a potential route of introduction and establishment. Carp (Cyprinus carpio) have been imported to the UK from Australia for release into still-water fisheries. A qualitative risk assessment concluded that the likelihood of EHNV introduction and establishment in England and Wales with the importation of a consignment of carp was very low. The level of uncertainty at a number of steps in the risk assessment scenario tree was high, notably the likelihood that carp become contaminated with the virus and whether effective contact (resulting in pathogen transmission) is made between the introduced carp and susceptible species in England and Wales. The virus would only establish when the water temperature is greater than 12 °C. Analysis of 10 years of data from two rivers in south-west England indicated that establishment could occur over a period of at least 14 weeks a year in southern England (when average water temperature exceed 12 °C). Imports of live fish from Australia need to be evaluated on a case-by-case basis to determine which, if any, sanitary measures are required to reduce the assessed risk to an acceptable level.     

Diagnosis of ovine fascioliasis by a dot enzyme-linked immunosorbent assay: a rapid microdiagnostic technique

A microenzyme-linked immunosorbent assay (dot-ELISA) was modified for making an immunodiagnosis of Fasciola hepatica infections in sheep. Sheep were alloted as follows: group I-3 controls and 4 principals, each inoculated with 500 metacercariae; group II-3 controls and 7 principals, each inoculated with 250 metacercariae; and group III-3 controls and 7 principals, each inoculated with 500 metacercariae. Blood and fecal samples were collected from each animal every 2 weeks for 16 weeks. Presence (or absence) of flukes was confirmed by fecal examinations and examination of dissected livers at necropsy of the sheep. The dot-ELISA incubations were done at ambient room temperature. Nitrocellulose disks dotted with 1 microliter (50 ng of protein) of F hepatica excretory/secretory products were placed in 96-well tissue culture plates. After nonspecific binding sites on the disks were bound with bovine serum albumin-triethanolamine-buffered saline solution, dilutions (1:2) of positive- and negative-control serum samples or experimental serum samples were placed in appropriate wells for a 30-minute incubation. Wells were washed (3 times), and 50 microliters of horseradish peroxidase conjugated rabbit anti-sheep immunoglobulin G was added to each well for a 30-minute incubation and then aspirated. Substrate solution (4-chloro-1-naphthol, methanol, triethanolamine-buffered saline solution, and H2O2; 50 microliters) was added for a 30-minute incubation and then aspirated. Disks were air dried for visualization: solid purple dot = positive sample, or no dot = negative sample.(ABSTRACT TRUNCATED AT 250 WORDS)     

New insights into the morphology, molecular characterization and identification of Baylisascaris transfuga (Ascaridida, Ascarididae)

Species ranked within the genus Baylisascaris (Ascaridida, Ascarididae) have been implicated in clinical and subclinical intestinal diseases in their natural hosts (e.g., raccoons and bears) as well as in life-threatening larva migrans syndromes in a number of incidental hosts, including humans. Following the diagnosis of Baylisascaris transfuga infestation in two captive polar bears, living in the zoo park of Pistoia (Tuscany, Italy), nematodes (n=300; both sexes) have been characterized by morphological and molecular methods by sequencing and analysing ribosomal (large ribosomal DNA (28S) and internal transcribed spacer region 1 and 2 (ITSs)) and mitochondrial (cytochrome c oxidase subunit 1 (cox1) and cytochrome c oxidase subunit 2 (cox2)) target regions. In addition, seven faecal samples were collected from the animal enclosure and submitted to copromicroscopic and molecular examination. All nematodes were morphologically identified as B. transfuga and their main distinctive features are here presented. No variation in size and nucleotide polymorphisms was detected within each target sequence among all samples analysed. These data contribute to facilitate an accurate diagnosis of this little known nematode infestation in order to apply appropriate anthelmintic strategies.