The National Veterinary Institute

Sentrum, Norway

The National Veterinary Institute

Sentrum, Norway
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Andersson A.-M.,The National Veterinary Institute | Nyman A.-K.,The National Veterinary Institute | Wallgren P.,The National Veterinary Institute
Preventive Veterinary Medicine | Year: 2017

Aleutian Disease (AD) is an important disease in mink characterized by a persistent chronic infection typically causing a progressive disease with symptoms such as weight loss, polydipsia, polyuria, reduced reproductive performance and increased herd mortality. Due to lack of success in eradicating AD by stamping out, disease control programs based on estimating the disease progression have been implemented and used in the selection of future breeding animals. The aim of this project was to evaluate the association between the reproductive performance of female mink (expressed as being barren or not and litter size of non-barren females) and the individual AD status (defined as diseased or non-diseased based on the OD450 value in a dried blood spot samples (DBS) VP2 ELISA) while controlling for age and color type. The project included a pilot study with data on OD450 values and reproductive performance of 2067 female mink in one herd and a follow-up study with data from 10,368 primiparous female mink in four different herds. To investigate the association between the reproductive performance and the AD status, a multivariable zero-inflated Poisson regression model was used in the pilot study and an univariable mixed-effect logistic and Poisson regression model was used in the follow-up study. In the pilot study, being barren was significantly associated with age in an interaction with the AD status of the female mink with the highest risk among the primiparous diseased mink and lowest risk among older non-diseased mink (OR = 5.8; p < 0.001). In addition, color type was significantly associated with being barren. Age was also significantly associated with litter size, where older female mink gave birth to approximately 5% larger litters. However, no significant association was found between the litter size and the AD status of the female mink. In the follow-up study, both being barren as well as litter size were significantly associated with the AD status of the female mink (OR = 1.6 (p < 0.001) and IRR = −0.95 (p < 0.001), respectively). Our results demonstrated an association between the reproductive performance of the female mink and the individual AD status. The effect of disease on litter size was minor compared to the effect on the barren percentage. Thus, assessment of the AD status with the DBS VP2 ELISA can be concluded to be a valuable tool for improving the reproductive performance of mink herds. Selection of primiparous female mink with low OD450 values for breeding will reduce the risk of having barren females. © 2017 Elsevier B.V.


Asefa D.T.,The National Veterinary Institute | Kure C.F.,N 1430 As | Gjerde R.O.,Stranda Spekemat AS | Omer M.K.,Norwegian Meat and Poultry Research Center | And 2 more authors.
International Journal of Food Microbiology | Year: 2010

The aims of this study were to investigate the patterns of fungal growth on dry-cured meat products, identify the important sources and factors of contamination and recommend intervention measures. The production processes of two smoked dry-cured hams and one unsmoked dry-cured leg of lamb were studied. A longitudinal observational study was performed to collect 642 samples from the meat, production materials, room installations and indoor and outdoor air of the production facility. Standard mycological isolation and identification procedures were followed. Totally, 901 fungal isolates were obtained; of which 57% were moulds while 43% were yeast. Yeasts were dominant on meat surfaces by covering 64% of the isolates. Mould growth was not observed until late in the dry-ripening stage. Yeasts and moulds were isolated from half of the environmental samples, of which moulds contributed by 80%. More than 39 mould species were isolated from the entire production process with a 77% contribution by the species of Penicillium. Penicillium nalgiovense dominated the species composition of moulds isolated from the products and the production environment. A preliminary bioassay analysis on bacterial colonies indicated that most of the P. nalgiovense isolates have the ability to produce penicillin. Such isolates might produce penicillin on the products and can become potential food safety hazards. Improper pressing at the salting process, the air quality in salting, brining and smoking rooms and activities in the sorting room were identified as important factors and sources of fungal contamination. Technical solutions and organized production activities that reduce crack formation, airborne spore concentration and improve air circulation in the facility are recommended as intervention measures. © 2010 Elsevier B.V.


Asefa D.T.,The National Veterinary Institute | Kure C.F.,N 1430 As | Gjerde R.O.,Stranda Spekemat AS | Langsrud S.,N 1430 As | And 2 more authors.
Food Control | Year: 2011

This work provided a HACCP plan for mycotoxigenic hazards associated with dry-cured meat production facility. Mycotoxigenic hazards that could emerge at each stage of the production were described. Pathogenic yeasts, toxic secondary metabolites of toxigenic moulds were identified as the potential hazards. Smoking and the dry-ripening stages of production were the critical control points identified. Critical limits for the critical control points were set based on scientific premises and recommendations set by legislative authorities. The status of the critical limits at the identified critical control points need to be monitored, verified and recorded. © 2010 Elsevier Ltd.


PubMed | Collège de France, 4 ANSES Dozule Laboratory for Equine Diseases, Szent Istvan University, The National Veterinary Institute and 3 more.
Type: Journal Article | Journal: Vector borne and zoonotic diseases (Larchmont, N.Y.) | Year: 2016

Various methods are currently used for the early detection of West Nile virus (WNV) but their outputs are not quantitative and/or do not take into account all available information. Our study aimed to test a multivariate syndromic surveillance system to evaluate if the sensitivity and the specificity of detection of WNV could be improved.Weekly time series data on nervous syndromes in horses and mortality in both horses and wild birds were used. Baselines were fitted to the three time series and used to simulate 100 years of surveillance data. WNV outbreaks were simulated and inserted into the baselines based on historical data and expert opinion. Univariate and multivariate syndromic surveillance systems were tested to gauge how well they detected the outbreaks; detection was based on an empirical Bayesian approach. The systems performances were compared using measures of sensitivity, specificity, and area under receiver operating characteristic curve (AUC).When data sources were considered separately (i.e., univariate systems), the best detection performance was obtained using the data set of nervous symptoms in horses compared to those of bird and horse mortality (AUCs equal to 0.80, 0.75, and 0.50, respectively). A multivariate outbreak detection system that used nervous symptoms in horses and bird mortality generated the best performance (AUC=0.87).The proposed approach is suitable for performing multivariate syndromic surveillance of WNV outbreaks. This is particularly relevant, given that a multivariate surveillance system performed better than a univariate approach. Such a surveillance system could be especially useful in serving as an alert for the possibility of human viral infections. This approach can be also used for other diseases for which multiple sources of evidence are available.


PubMed | The National Veterinary Institute, University of Caen Lower Normandy, French National Institute for Agricultural Research and Veterinary Public Health Institute
Type: Journal Article | Journal: PloS one | Year: 2014

In this work we propose the adoption of a statistical framework used in the evaluation of forensic evidence as a tool for evaluating and presenting circumstantial evidence of a disease outbreak from syndromic surveillance. The basic idea is to exploit the predicted distributions of reported cases to calculate the ratio of the likelihood of observing n cases given an ongoing outbreak over the likelihood of observing n cases given no outbreak. The likelihood ratio defines the Value of Evidence (V). Using Bayes rule, the prior odds for an ongoing outbreak are multiplied by V to obtain the posterior odds. This approach was applied to time series on the number of horses showing clinical respiratory symptoms or neurological symptoms. The separation between prior beliefs about the probability of an outbreak and the strength of evidence from syndromic surveillance offers a transparent reasoning process suitable for supporting decision makers. The value of evidence can be translated into a verbal statement, as often done in forensics or used for the production of risk maps. Furthermore, a Bayesian approach offers seamless integration of data from syndromic surveillance with results from predictive modeling and with information from other sources such as disease introduction risk assessments.


PubMed | Swedish University of Agricultural Sciences, Uppsala University and The National Veterinary Institute
Type: Journal Article | Journal: BMC immunology | Year: 2016

Serglycin proteoglycans are essential for maturation of secretory granules and for the correct granular storage of cationic proteases in hematopoietic cells, e.g. mast cells. However, little is known about the in vivo functions of serglycin proteoglycans during infection. Here we investigated the potential role of serglycin proteoglycans in host defense after infection with the nematode Trichinella spiralis.Twelve days post infection lack of serglycin proteoglycans caused significantly increased enteropathy. The serglycin-deficient mice showed significantly increased intestinal worm burden, reduced recruitment of mast cells to the intestinal crypts, decreased levels of the mast cell proteases MCPT5 and MCPT6 in intestinal tissue, decreased serum levels of TNF-, IL-1, IL-10 and IL-13, increased levels of IL-4 and total IgE in serum, and increased intestinal levels of the neutrophil markers myeloperoxidase and elastase, as compared to wild type mice. At five weeks post infection, increased larvae burden and inflammation were seen in the muscle tissue of the serglycin-deficient mice.Our results demonstrate that the serglycin-deficient mice were more susceptible to T. spiralis infection and displayed an unbalanced immune response compared to wild type mice. These findings point to an essential regulatory role of serglycin proteoglycans in immunity.


Patent
Columbia University and The National Veterinary Institute | Date: 2016-06-14

The invention is directed to immunogenic compositions and methods for inducing an immune response against Piscine reoviruses in an animal. In another aspect, the invention relates to antibodies that bind Piscine reovirus polypeptides. In yet another aspect, the invention relates to methods for preventing, or reducing PRV infection in an animal.


PubMed | Uppsala University, The National Veterinary Institute and Harvard University
Type: Journal Article | Journal: Journal of immunology (Baltimore, Md. : 1950) | Year: 2014

Allergic asthma is a complex disease with a strong genetic component where mast cells play a major role by the release of proinflammatory mediators. In the mouse, mast cell protease-6 (mMCP-6) closely resembles the human version of mast cell tryptase, -tryptase. The gene that encodes mMCP-6, Tpsb2, resides close by the H-2 complex (MHC gene) on chromosome 17. Thus, when the original mMCP-6 knockout mice were backcrossed to the BALB/c strain, these mice were carrying the 129/Sv haplotype of MHC (mMCP-6(-/-)/H-2bc). Further backcrossing yielded mMCP-6(-/-) mice with the BALB/c MHC locus. BALB/c mice were compared with mMCP-6(-/-) and mMCP-6(-/-)/H-2bc mice in a mouse model of experimental asthma. Although OVA-sensitized and challenged wild type mice displayed a striking airway hyperresponsiveness (AHR), mMCP-6(-/-) mice had less AHR that was comparable with that of mMCP-6(-/-)/H-2bc mice, suggesting that mMCP-6 is required for a full-blown AHR. The mMCP-6(-/-)/H-2bc mice had strikingly reduced lung inflammation, IgE responses, and Th2 cell responses upon sensitization and challenge, whereas the mMCP-6(-/-) mice responded similarly to the wild type mice but with a minor decrease in bronchoalveolar lavage eosinophils. These findings suggest that inflammatory Th2 responses are highly dependent on the MHC-haplotype and that they can develop essentially independently of mMCP-6, whereas mMCP-6 plays a key role in the development of AHR.


PubMed | Uppsala University and The National Veterinary Institute
Type: | Journal: Infection ecology & epidemiology | Year: 2016

In Sweden, human cases of Puumala hantavirus (PUUV) infections are reported from the northern endemic regions. We found hantavirus-specific antibodies in yellow-necked mice (Apodemus flavicollis) trapped in human dwellings in the surroundings of the cities of Uppsala and Stockholm, which are situated far south from the traditional endemic areas of PUUV. Because the yellow-necked mouse is the most common rodent in human dwellings, hantaviruses in this rodent species may be important for the public health.


PubMed | The National Veterinary Institute
Type: | Journal: Acta veterinaria Scandinavica | Year: 2013

Aleutian disease in mink is caused by infection with Aleutian mink disease virus (AMDV). In Sweden, the infection most commonly causes classical Aleutian disease in which the immune system fails to neutralize the virus and the infection becomes persistent. Diagnosis of AMDV infection is based on serological methods that detect virus-specific antibodies. Traditionally counterimmunoelectrophoresis (CIEP) has been the preferred method, but in order to enable automation interest has been paid to other antibody detecting systems. Recently, at least two different ELISA systems that detect antibodies to AMDV have been manufactured; one is based on an in vitro grown AMDV as antigen, and the other system is based on the AMDV capsid protein VP2 as antigen. The aim of this study was to evaluate the two ELISA systems for detection of antibodies to AMDV using CIEP as the gold standard.When employing the mean optical density of the samples from CIEP negative mink plus three standard deviations as cut-off value, the ELISA with the VP2 antigen had a sensitivity of 99.7% and a specificity of 98.3% compared to CIEP (n=364). Analysis of samples with the AMDV-G antigen based ELISA employing an assay cut-off value based on the negative control samples, as suggested by the manufacturer, resulted in a sensitivity of 54.3% and a specificity of 93.2% with reference to CIEP as the gold standard (n=359). When employing the mean optical density of the samples from CIEP negative mink plus three standard deviations as cut-off value, the AMDV-G ELISA had a sensitivity of 37.6% and a specificity of 98.3%.The ELISA system based on VP2 antigen had high sensitivity and specificity, and was concluded to be an alternative to the CIEP as a diagnostic tool for AMDV antibodies. In contrast, the AMDV-G ELISA suffered from low sensitivity when compared to CIEP.

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