No description available.

No description available.

Background: As a part of a national health control program, Statens VeterinärmedicinskaAnstalt performs diagnostics to screen flocks for certain pathogens causing high mortality,morbidity and/or serious economical losses. There are several viruses in the programincluding IBDV (infectious bursal disease virus), IBV (infectious bronchitis virus) and NDV(Newcastle disease virus). Method: 96 serum samples were collected from different poultryflocks in Sweden and analyzed by ELISA, which are currently used in the health controlprogram as well as by a commercial prototype of a multiplex immunoassay manufactured byLuminex Corp., which is currently under evaluation at the United States Department ofAgriculture USDA. This 4-plex assay detects antibodies for the three above-mentionedviruses as well as antibodies of avian reovirus. In the context of this study the ELISAs run inroutine diagnostics as well as a REO ELISA were used as the standard for comparison.Result: The antibody concentration in serum from vaccinated chickens was high while theantibody concentration level in serum from not vaccinated chickens was low. There was agood correlation between the multiplex assay and ELISA. Conclusion: The results obtainedin this study indicate that the Luminex multiplex assay tested has the potential to be usedroutinely for screening flocks.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 77-89).

The very virulent (vv) pathotype of infectious bursal disease virus (IBDV) has spread rapidly throughout Europe, Asia, and the Middle East. Although Australia is currently unaffected, there remains the potential for incursion of an exotic isolate. The aim of this study was to identify putative virulence determinants of IBDV to facilitate the development of improved diagnostic assays for detection and characterisation of vvIBDV isolates. Sequencing of Indonesian vvIBDV Tasik94 revealed a unique substitution [ A¨S222] in the hypervariable region (HVR) of viral protein (VP) VP2, which did not appear to impinge on virulence or antigenicity. Phylogenetic analyses indicated that Tasik94 was closely related to Asian and European vvIBDV strains. Extensive alignment of deduced protein sequences across the HVR of VP2 identified residuesI242 I256 and I294 as putative markers of the vv phcnotype. Comparison of the pathology induced by mildly-virulent Australian IBDV 002/73 and Indonesian vvIBDV Tasik94, revealed that histological lesions in the spleen, thymus and bone marrow were restricted to Tasik94-infected birds, suggesting the enhanced pathogenicity of vvIBDV might be attributed to replication in non-bursal lymphoid organs. The biological significance of the VP2 HVR in virulence was assessed using recombinant viruses generated by reverse genetics. Both genomic segments of Australian IBDV 002/73, and recombinant segment A constructs in which the HVR of 002/73 was replaced with the corresponding region of either tissue culture-adapted virus or vvIBDV (Tasik94), were cloned behind T7 RNA polymerase promoter sequences. In vitro transcription/translation of each construct resulted in expression of viral proteins. Co-transfection of synthetic RNA transcripts initiated replication of both tissue culture-adapted parental and recombinant viruses, however attempts to rescue non-adapted viruses in specific-pathogen-free (SPF) chickens were unsuccessful. Nucleotide sequence variation in the HVR of VP2 was exploited for the development of a new diagnostic assay to rapidly detect exotic IBDV isolates, including vvIBDV, using reverse transcription polymerase chain reaction (RT-PCR) amplification and Bmrl restriction enzyme digestion. The assay was capable of differentiating between endemic and exotic IBDV in 96% of 105 isolates sequenced to date.

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-21T13:33:38Z No. of bitstreams: 1 PGCA17MA227.pdf: 1295144 bytes, checksum: d5bbe4c0123a299ec156229a16f2d98a (MD5) / Made available in DSpace on 2018-03-21T13:33:38Z (GMT). No. of bitstreams: 1 PGCA17MA227.pdf: 1295144 bytes, checksum: d5bbe4c0123a299ec156229a16f2d98a (MD5) Previous issue date: 2017-07-14 / Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) belong to the Retroviridae family, being the most important viral infectious agents in cats. FeLV infection is commonly manifested through immunosuppression, anemia, and lymphoma. FIV is responsible for primarily depleting immune system action of the host. The prevalence of these viral infections varies in different locations around the world. In Brazil, there is a lack of data about highest prevalence of infected animals. Therefore, a cross-sectional study was conducted to determine the prevalence and related factors in FeLV and FIV infections in cat from Santa Catarina Plateau. In the meantime, a second study was conducted with the objective of describing and comparing the clinical and hematological changes that affect FeLV positive domestic cats. The prevalence was 22.26% (61/274) for FeLV infection, 5.84% (16/274) for FIV and 1.46% (4/274) for both viruses. Cats that presented aggressive behavior (OR = 1.18) and males (OR = 2.41) were more likely to be FeLV positive. Aggressive cats (OR = 8.00), males (OR = 5.87) and older (OR = 1.01) had a greater chance of testing positive for FIV. The most observed clinical sign in FeLV positive sick cats was pallor of mucous membranes (65, 51%; 19/29), followed by neurological changes (20, 69%; 6/29), lymphoma (17, 24%; 5/29), secondary infections (10, 34%; 3/29) and leukemia (6.9%; 2/29). At the complete blood count, the means found in Group 3 (FeLV positive and affected by viral disease) were lower than for Groups 1 (FeLV negative and healthy) and 2 (FeLV positive and asymptomatic) for erythrocyte counts, hemoglobin concentration, hematocrit and eosinophils, while for nucleated erythrocytes was higher. The mean number for corpuscular volume was higher in the Group 3 than Group 1. At the same time, platelet count was lower. The most frequent hematological changes in Group 3 were anemia (65, 51%; 9/29) and thrombocytopenia (62.7%; 18/29). Hematological changes found in FeLV positive and symptomatic felines are more severe than those found in healthy FeLV felines. The prevalence for FeLV infection was high, showing that the local feline population is at risk and it is needed to implement measures to control the disease spreading / O vírus da leucemia felina (FeLV) e o vírus da imunodeficiência felina (FIV) pertencem a família Retroviridae e são os agentes infecciosos virais mais importantes em gatos. A infecção pelo FeLV é manifestada comumente através de imunossupressão, anemia e linfoma. O FIV é responsável por causar principalmente depleção da ação do sistema imune do hospedeiro. A prevalência para a infecção por esses vírus varia entre diferentes regiões no planeta. No Brasil há poucos dados, aonde é possível observar alta prevalência de animais infectados. Portanto, um estudo transversal foi realizado para determinar a prevalência e os fatores associados a infecção por FeLV e FIV em gatos do Planalto de Santa Catarina. Em paralelo um segundo estudo foi conduzido, com o objetivo de descrever e comparar as alterações clínicas e hematológicas que acometem os gatos domésticos FeLV positivos. A prevalência encontrada foi 22,26% (61/274) para a infecção por FeLV, 5,84% (16/274) para FIV e 1,46% (4/274) para ambos os vírus. Gatos que apresentaram comportamento agressivo (OR=1.18) e machos (OR=2.41) apresentaram maior chance de ser positivos para FeLV. Gatos agressivos (OR= 8.00), machos (OR= 5.87) e mais velhos (OR=1,01) apresentaram maior chance de testar positivo pra FIV. A apresentação clínica mais observada nos gatos FeLV positivos e doentes foi palidez de mucosa (65,51%; 19/29); alterações neurológicas (20,69%; 6/29); linfoma (17,24%; 5/29); coinfecções (10,34%; 3/29) e leucemia (6,9%; 2/29). No hemograma, as médias encontradas para o Grupo 3 (FeLV positivos e com doença causada pelo vírus) foram menores que para os Grupos 1 (FeLV negativos e saudáveis) e 2 (FeLV positivos e assintomáticos) para contagem de eritrócitos, concentração de hemoglobina, hematócrito e eosinófilos, enquanto para eritrócitos nucleados foi maior. A média encontrada para volume globular médio foi maior para o Grupo 3 que para o Grupo 1 e para a contagem de plaquetas foi menor. As alterações hematológicas mais encontradas no Grupo 3 foram a anemia [65,51%; 19/29] e a trombocitopenia [62,7%; 18/29]. As alterações hematológicas encontradas em felinos FeLV positivos e sintomáticos são mais severas que as encontradas em felinos FeLV positivos saudáveis. A prevalência para a infecção por FeLV é alta, colocando a população de felinos da região em risco e demonstrando a necessidade de implementação de medidas de controle da disseminação da doença

Over the past few years one of the major concerns in the Atlantic salmon (Salmo salar) farming industry has been the increasing incidence and severity of inflammatory viral diseases. Heart and skeletal muscle inflammation (HSMI) and cardiomyopathy syndrome (CMS) are currently two of the most prevalent viral diseases in commercial Atlantic salmon farms in Norway. Mortality levels in both diseases are generally low but morbidity can be very high with the associated chronic inflammatory response lasting for several months. The consequent reduced growth performance is causing considerable financial impact as HSMI has become increasingly widespread in recent years. The impact of CMS is further exacerbated as it generally affects large fish close to harvest. HSMI lesions occur in the atrium and ventricle in the heart including inflammation and necrosis in epi- endo- and myocardium along with myositis of red skeletal muscle. CMS lesions are commonly observed in the spongy myocardium in the atrium and ventricle of the heart with severe mononuclear inflammation and necrosis. Furthermore, circulatory disturbances associated with reduced cardiac function cause multifocal liver steatosis and necrosis in both diseases. Currently there are no vaccines or any other effective treatments for these diseases and so alternative therapies that could potentially modulate the intensity of the inflammatory response could be crucial to improve the clinical manifestation of the diseases. Therefore, the overall aim of the present study was to evaluate the concept of “clinical nutrition” to improve the clinical symptoms of both viral diseases, HSMI and CMS, through the use of functional feeds formulated with reduced lipid content and increased proportions of anti-inflammatory fatty acids to moderate the apparently uncontrolled inflammatory response in the heart tissue associated with both diseases and also alleviate the secondary hepatic lesions. The experimental work consisted of three major dietary trials in Atlantic salmon in seawater. Two large trials investigated the effects of functional feeds in Atlantic salmon challenged with Atlantic salmon piscine reovirus (ASRV) and piscine myocarditis virus (PMCV), the causal agents of HSMI and CMS, respectively. In both trials, heart transcriptome, heart and liver histopathology and tissue lipid and fatty acid compositions and metabolism were determined post-infection in fish fed with the functional feeds in comparison with fish fed with a standard commercial feed formulation considered as a reference diet. All the functional feeds were formulated to have reduced digestible energy through lower dietary lipid and higher protein contents, and increased levels and proportions of anti-inflammatory long-chain polyunsaturated fatty acids (LC-PUFA), particularly eicosapentaenoic acid (EPA) compared with the reference diets. Histopathology, fatty acid composition and gene expression of heart were assessed over a long time-period of 16 weeks and 14 weeks post-challenge with ASRV and PMCV, respectively. Viral load in heart tissue, hepatic histopathology and fatty acid composition of liver and head kidney along with expression of the genes involved in the eicosanoid and LC-PUFA and eicosanoid biosynthesis pathways were also determined in the HSMI trial. The third trial was a nutritional trial evaluating the effects of dietary digestible energy content on lipid and fatty acid metabolism in salmon fed diets containing graded amounts of lipid. Fatty acid composition of liver and heart were assessed over 12 weeks, along with the hepatic expression of genes of lipid and fatty acid metabolism. The results of this research are presented in four chapters (Chapters 2-5) as four paper manuscripts. The manuscripts/Papers are either published (Chapter 2), in review (Chapter 3 and 4) or drafted for submission (Chapter 5) in appropriate peer-reviewed international journals. Chapter 2 and 3 correspond to the HSMI trial, Chapter 4 to the nutritional trial, and Chapter 5 to the CMS trial. Chapter 2 showed that viral load and histopathology scores were lower in fish fed the functional feeds, especially diet FF1, which displayed better performance. Diet strongly influenced the expression of genes related with the immune and inflammatory responses, with delayed expression in fish fed the functional feeds. Up-regulation of pro-inflammatory genes was correlated with the higher viral load observed at early-mid stages of the disease in fish fed the reference diet (ST). Expression of genes related with the immune response at 16-weeks post challenge reflected the differences in immunomodulation between the functional feeds, with fish fed diet FF1 showing lower expression. Therefore, severity of the heart lesions was correlated with the intensity of the immune response and could be associated with tissue anti-inflammatory LC-PUFA levels. Chapter 3 was focused on liver histopathology, fatty acid composition and LC-PUFA biosynthesis, along with phospholipid fatty acid composition and eicosanoid production in head kidney and heart tissue at early and late stages of ASRV infection. Liver was severely affected by the virus at the beginning of the infection in fish fed the reference ST diet, but the level of lesions were similar in all dietary groups at the end of the trial. Hepatic expression of fatty acyl desaturases was significantly depressed in fish fed the ST diet compare with fish fed the functional feeds despite the lower levels of dietary LC-PUFA in that feed. Thus endogenous production and bioavailability of anti-inflammatory LC-PUFA was potentially enhanced in fish fed the functional feeds. Changes in tissue lipid content, mobilization of fatty acids involved in inflammatory responses and changes in expression of transcription factors and genes involved in eicosanoid biosynthesis were more prominent in head kidney, confirming the important role of this organ in dietary immunomodulation after viral infection. To a lesser extent similar changes were observed in heart tissue, suggesting in situ production of eicosanoids could also be important. The unexpected effects of diet on expression of genes of LC-PUFA biosynthesis were specifically investigated in the trial described in Chapter 4. One aim of this study was to clarify whether dietary lipid content or viral infection was the cause of altered expression of desaturase genes between the different diets. Hepatic expression of other genes of lipid and fatty acid metabolism were also determined to evaluate metabolic changes associated with dietary lipid/energy level. In general, reduction of dietary energy and lipid contents while maintaining similar proportions of dietary fatty acids, led to a general up-regulation of genes involved in lipid biosynthetic pathways. Thus salmon fed lower energy diet showed increased liver expression of fatty acyl desaturases in comparison with fish fed higher energy levels. Heart transcriptomic data in Chapter 5 showed a similar delay in the inflammatory response in fish fed the functional feeds after PCMV infection as observed in the HSMI study. Modulation of inflammatory responses, similar to that previously described after ASRV infection, was also observed in fish fed the functional feeds. However, the differences in the expression of immune related genes and the level of heart lesions were not as prominent at mid-late stages of the disease as in fish fed FF1 in the HSMI trial. The present study demonstrated the beneficial effects of a clinical nutrition approach via functional feeds in two viral inflammatory diseases, HSMI and CMS, currently affecting farmed Atlantic salmon.

Dengue, a group of four similar viruses transmitted through the bite of a mosquito, is estimated to infect upwards of 100 million annually in over 100 nations throughout the global equatorial belt. Distribution of global dengue is highly skewed as Southeast Asian and Western Pacific regions endure 75% of the global dengue burden. Similar to other regional countries, Malaysia has been rapidly urbanizing, which has supported a hyperendemic dengue state. The biological pathway by which dengue infection causes a wide range of clinical manifestations, spanning asymptomatic to life-threatening severe complications, is not comprehensively understood. Historically, severe dengue complications have primarily occurred in children. Consequentially, the majority of the dengue biological pathway research has been conducted on children; however, extrapolation of research findings to adults may be inappropriate as dengue manifestations have differed between age groups. As developing countries undergo epidemiologic transitions and dengue continues to spread geographically to non-endemic regions, youth and adult populations have been subjected to more of the severe dengue burden. Epidemiology and laboratory-based evidence has supported both memory T-cell and antibody independent enhancement hypotheses to explain the biological pathway of severe dengue. Both hypotheses employ the central idea that a primary infection alters immune components so that during a secondary heterotypic dengue infection, an individual is more at risk for severe complications. Monocytes, immune cells that are pivotal in both hypotheses, have been highly examined through in vivo and in vitro experimentation; however, epidemiological evidence for monocyte involvement is incomplete. The primary objective of the study was to examine if a difference in absolute monocyte count, considering independent risk factors, is present in individuals with primary and secondary dengue infections. A secondary dengue infection was found to raise absolute monocyte count during the defervescence phase of dengue illness in individuals aged 15 years and older 0.71 ± 0.15 (x10^9) compared to those experiencing primary dengue infection. Gender and distance of study participants' residences from Hospital Ampang were found to be risk factors for the relationship of interest; whereas, age and race were not found to be significant risk factors. The study helps expand current knowledge of the severe dengue biological pathway with respect to immunological differences between primary and secondary dengue infections. Further research is needed to confirm and expand the findings of this initial study, specifically to include infecting dengue serotype, education, and socioeconomic status which are known dengue risk factors.

Língua Azul (LA) é uma doença causada pelo Vírus da Língua Azul (VLA) e transmitida por vetores do gênero Culicoides. Estudos sorológicos tem demonstrado a ampla presença do vírus no Brasil, entretanto, informações clínicas da LA na América do Sul são limitadas. Este trabalho descreve alterações clínico-patológicas em ovinos acometidos pela LA no Estado do Rio Grande do Sul, Brasil. Em dois surtos, em propriedades distintas, 15 ovinos apresentaram como principais sinais clínicos hipertermia, apatia, aumento de volume da face e região submandibular, dificuldade de deglutição com regurgitação, secreção nasal mucopurulenta esverdeada, alterações respiratórias, além de acentuada perda de peso e erosões na mucosa oral. Seis ovinos que morreram, apresentaram à necropsia edema subcutâneo na face e região ventral do tórax, secreção nasal de coloração esverdeada, esôfago dilatado e preenchido por grande quantidade de conteúdo alimentar, pulmões não colabados, com áreas de consolidação anteroventrais, e luz da traquéia e brônquios com conteúdo espumoso misturado a conteúdo alimentar. No coração e base da artéria pulmonar observaram-se focos de hemorragia. Histologicamente as principais alterações observadas foram no tecido muscular cardíaco e esquelético, em especial no esôfago, com degeneração hialina e flocular, necrose bifásica e micro-mineralização de miofibras associadas a infiltrado inflamatório mononuclear. Pneumonia aspirativa associada à presença de material vegetal e bactérias na luz de brônquios também foi observada e foi considerada a responsável pela gravidade das manifestações clínicas e pelas mortes. O diagnóstico de LA foi confirmado pelo duplex RT-PCR com a identificação do VLA, sorotipo 12. / Bluetongue (BT) is a disease caused by bluetongue virus (BTV) and transmitted by vectors of the genus Culicoides. Serological studies have demonstrated the widespread distribution of the virus in Brazil, however, clinical information of BT in South America are limited. This paper describes clinical and pathological changes in sheep affected by BTV in southern Brazil. In two outbreaks on different farms, 15 sheep showed clinical signs as severe hyperthermia, apathy, swelling of the face and submandibular area, difficulty in swallowing with regurgitation, greenish mucopurulent nasal secretion, severe weight loss and erosions in the oral mucosa. Six sheep that eventually died, shall necropsy showed subcutaneous edema in the face and ventral region of the chest, runny nose of green color, and dilated esophagus filled with adundant food content, lungs collapsed, with areas of antero ventral consolidation and trachea and bronchi containing foamy contents mixed with food. Heart and base of the pulmonary artery showing foci of hemorrhage. Histologically, the main changes were in cardiac and skeletal muscles and consisted of biphasic lesions characterized by hyaline and floccular degeneration/necrosis of myofibers associated with micro-mineralization and mononuclear cell infiltration. Pneumonia associated with the presence of organic matter and bacteria in the lumen of the bronchi was also observed. The diagnosis of BT was confirmed by duplex RT-PCR to the identification of the BTV, serotype 12.

Língua Azul (LA) é uma doença causada pelo Vírus da Língua Azul (VLA) e transmitida por vetores do gênero Culicoides. Estudos sorológicos tem demonstrado a ampla presença do vírus no Brasil, entretanto, informações clínicas da LA na América do Sul são limitadas. Este trabalho descreve alterações clínico-patológicas em ovinos acometidos pela LA no Estado do Rio Grande do Sul, Brasil. Em dois surtos, em propriedades distintas, 15 ovinos apresentaram como principais sinais clínicos hipertermia, apatia, aumento de volume da face e região submandibular, dificuldade de deglutição com regurgitação, secreção nasal mucopurulenta esverdeada, alterações respiratórias, além de acentuada perda de peso e erosões na mucosa oral. Seis ovinos que morreram, apresentaram à necropsia edema subcutâneo na face e região ventral do tórax, secreção nasal de coloração esverdeada, esôfago dilatado e preenchido por grande quantidade de conteúdo alimentar, pulmões não colabados, com áreas de consolidação anteroventrais, e luz da traquéia e brônquios com conteúdo espumoso misturado a conteúdo alimentar. No coração e base da artéria pulmonar observaram-se focos de hemorragia. Histologicamente as principais alterações observadas foram no tecido muscular cardíaco e esquelético, em especial no esôfago, com degeneração hialina e flocular, necrose bifásica e micro-mineralização de miofibras associadas a infiltrado inflamatório mononuclear. Pneumonia aspirativa associada à presença de material vegetal e bactérias na luz de brônquios também foi observada e foi considerada a responsável pela gravidade das manifestações clínicas e pelas mortes. O diagnóstico de LA foi confirmado pelo duplex RT-PCR com a identificação do VLA, sorotipo 12. / Bluetongue (BT) is a disease caused by bluetongue virus (BTV) and transmitted by vectors of the genus Culicoides. Serological studies have demonstrated the widespread distribution of the virus in Brazil, however, clinical information of BT in South America are limited. This paper describes clinical and pathological changes in sheep affected by BTV in southern Brazil. In two outbreaks on different farms, 15 sheep showed clinical signs as severe hyperthermia, apathy, swelling of the face and submandibular area, difficulty in swallowing with regurgitation, greenish mucopurulent nasal secretion, severe weight loss and erosions in the oral mucosa. Six sheep that eventually died, shall necropsy showed subcutaneous edema in the face and ventral region of the chest, runny nose of green color, and dilated esophagus filled with adundant food content, lungs collapsed, with areas of antero ventral consolidation and trachea and bronchi containing foamy contents mixed with food. Heart and base of the pulmonary artery showing foci of hemorrhage. Histologically, the main changes were in cardiac and skeletal muscles and consisted of biphasic lesions characterized by hyaline and floccular degeneration/necrosis of myofibers associated with micro-mineralization and mononuclear cell infiltration. Pneumonia associated with the presence of organic matter and bacteria in the lumen of the bronchi was also observed. The diagnosis of BT was confirmed by duplex RT-PCR to the identification of the BTV, serotype 12.